Are Vegetarians Healthier than Omnivores? A Soho Forum Debate

a vegan diet has been shown to upregulate genes that protect against cancer anytime you see a nutritional epidemiological study anything that says oh this is linked to that you know meat is linked to cancer or this is associated with that if the the likeliness the likelihood that that will be an accurate statement is 0 to 20% of the time vegan diets and lifestyle interventions have been shown to grow telomeres the caps at the ends of our chromosomes that correlate with our longevity it's not the fat you eat that becomes the fat in your blood but the carbohydrates you eat and vegetarian diets are almost always higher in carbohydrates more animal protein more premature death more plant protein less premature death that is just a critical flaw when you're saying let's assume a vegan vegetarian diet which we've only had access to that the last 20 to 30 40 years is something that we can rely upon for the whole human race when it doesn't supply the basic nutrients needed for human life tonight's resolution again reads there is little or no rigorous evidence that vision vegetarian diets are healthier than diets that include meat eggs and cheese arguing for the affirmative nina tae shoals nina nina please come to the stage our greens for the negative dr. David Katz David please come to the stage but Jane please close the voting right Nina you are rocketing through the affirmative so you're up please come to the mic Thanks great well I I feel like I missed out I didn't go to McDonald's before the debate because I could just stand up here and say tremendous and I'd win that would be it so well you know I'm very excited to be here I think there's a special free song of excitement actually in the room tonight because I don't know if many of you know it but there's actually it's sort of a history between David Katz and I that's from the past few years and and this is the first time that we've met so that's exciting and I'm going to just tell you a little bit about that I mean I'm I'm here because I wrote this book and when it came out in 2014 it was much acclaimed I had spent nearly a decade of my life diving into the science and read thousands and thousands of scientific studies and I got it was best book of the year by a number of really important outlets and lauded by medical journals and yet there was this Yale doctor who was writing these terrible things about me like he was saying I was only out to sell a book and that was the only reason I had written what I had written my book my book is based the central argument is that saturated fats have been unfairly vilified and do not actually cause heart disease and so so he said that I was only out to write a to sell books like yeah good plan spent a decade of your life store to write a nonfiction book but it got worse that I was a parasite of science and that I was a fool or a fanatic that I was Apparel or that I lived in a was a wingnut living in the basement of my mom I just want to know when I lived with my mom I was allowed to live on the top floor and and then it finally came to being quoted in The Guardian as saying I was like an animal unlike anything he'd ever seen before which really really hurt my feelings and a number of doctors wrote in to the Dean of Yale Medical School to say well what is going on here this is not very professional behavior and got the reply that that dr. Katz is not associated he doesn't teach her he's not a professor at the Medical School and he runs a research program at a local county hospital that got the name of Yale some years ago and so that made me feel better but I also just want to explain I've been asked like by so many people why I would be here tonight it is hard to be on stage with somebody who's been so uncivil to you and I'm and I guess my answer is is that I really believe in the science and I really think it's important I think these kinds of attacks are are just not about science it's so important that we understand and debate the real science I care so much about it so that is why I'm here and thank you so what are we debating we are debating a hypothesis that vegan and vegetarian diet diets are superior in health to diets with with animal foods in them in order for a hypothesis to be considered as somewhat true or we can we can start to believe in it it's truth it must be supported by rigorous evidence that's human clinical trials and those trials must be replicated and it must not be contradicted by a large body or really very many facts to the contrary which undermine it there's a wonderful quote by the biologist Thomas Huxley who said the a the great tragedy of science is the slaying of a beautiful hypothesis by an ugly fact so we are going to see if there are any of those ugly facts out there tonight why is this debate so very very important the true Health Initiative is dr. Katz's foundation and he says that you know we really everybody really should eat a plant-based plant predominant diet and he says that everybody agrees on this this is their point that everybody's in sync with this and I think dr. Katz and I agree that the that we are really struggling with the chronic diseases that afflict our country but there really is disagreement about what is the best diet to prevent those so I have to explain to you this really big word now nutri epidemiology and even longer nutritional epidemiology because in order for us to really talk about the science and nutrition we need to understand what is the science and nutrition so I'm going to take you on this little journey nutritional epidemiology is when you take a large group of people like this who all looks so happy right now and you ask them a bunch of questions what do you eat you exercise do you take pills what do you you know do you have a nice family life do you go to church and then you follow them over time and you see who succumbs to disease or eventually death what kinds of conditions do they get and so you have many many income variable variables all the things they eat and everything they do in their life and many many outcome variables everything that possible that could happen to human health and as really there's all these correlations like a thicket of correlations and what happens is you get false positives inevitably there are things that are going to correlate with each other that do not are not causation I mean here we have one of these correlations internet use causes breast cancer I don't think so maybe sitting in front of the computer all day it causes cancer who knows but this is a false positive here's another one a false positive whereby if you decrease the amount of margarine that you eat apparently you can save your marriage that seems cheaper than a marriage counselor but that is unlikely to be a causal link epidemiology only choses shows associations associations and nutritional epidemiology is particularly fraught because it depends on people reporting on what they ate so just imagine this so every six months you get a questionnaire how many apples did you eat on average over the last you know at six months every week how many pears how many how much lasagna and can you quantify that by cup and and and can you let's hope that that's the your lasagna is the same recipe as my lasagna in my database back here and how many people do you think out here just raise your hand if you might be likely to lie about how much sugar or alcohol that you imbibe right would so there's you know the science really shows that people not only don't remember what they eat but they lie about they don't mean to it's just they don't want to be seen as looking bad even in an anonymous questionnaire they don't want to think badly about themselves so this data is very unreliable I'm just gonna slide over this one but that the unreliability of that data is profound and that is really at the heart of the problem with using nutrition epidemiology there is a better kind of science called a clinical trial you know ideally a randomized controlled clinical trial and that's where I take a group of people like you and over here at this group I give you a pill or I give you a diet and this group over here I is my control group I give them a placebo or I give them a control diet and if you're a big enough group and I consume I can assume that everything else about you is equal except for the intervention the pillar of the diet and at the end of art period let's say a year I can decide let's say you risk group all drops dead from heart attacks I know that it's due to my unfortunate intervention and that is the kind of science that can show cause and effect so when nutritional epidemiological findings are tested in this more rigorous kind of science nutrition clinically I have been shown to be correct and in this one study by a Stanford professor only 20% of the time in this study they were pre correct zero percent of the time so anytime you see a nutritional epidemiological study anything that says oh this is linked to that you know meat is linked to cancer or this is associated with that it's the the likeliness the likelihood that that will be an accurate statement is zero to twenty percent of the time this latter study that showed that zero percent actually looked at all the findings of the most influential epidemiological database in the country at Harvard looked at all their findings they were the ones who tell us to take various supplements and also to do hormone replacement therapy to remember that all based on epidemiological findings altogether 52 of these epidemiological findings were studied and they found that zero percent of those could be confirmed in clinical trials and this is not an idle thing you remember hormone replacement therapy millions women are taking hormone replacement therapy only to find when they did the clinical trial that they had a higher risk of having a heart attack so this is not an idle matter that is that that is why we cannot trust this kind of science and why if you look anywhere in the world at systems for grading and understanding science they will put they will put in that middle layer that kind of aqua blue is where all the epidemiology is and on top of that in the darker blue is randomized control clinical trials that's where you start regardless of the system you're using whether it's the system [ __ ] crane from the UK or one called grade from from Canada it's controlled clinical trials that are the gold standard so just as you would not prescribe a pill to a patient based on an epidemiological study this is linked with that but we're not sure zero to twenty percent odds that were right you would not do that with a diet so what is the rigorous clinical trial evidence for a vegetarian or a vegan diet let's look at this the US dietary guideline committee in 2015 looked at all of the available trial evidence they could find at the time and and from an analysis that we did we found that 11 of 14 members in that expert committee actually themselves were had published in favor of plant-based diets so we knew that they were if there were more any trials to be found they would find them they had an incentive to find them they couldn't find any and they had to rank that evidence at the lowest possible grade that is available for when you have any evidence so that's the government's systematic review here's another systematic review of clinical trials and heart disease they could only find that only 836 people had been tested which is not very many and they found that although those trials lowered your LDL which is your bad cholesterol supposedly it also lowered your good cholesterol your HDL that came down in in a vegan vegetarian diet that's a sign of your heart disease risk increasing and those diets also almost always increase your triglycerides which are the fatty acids in your blood why because it's not the fat you eat that becomes the fat in your blood but the carbohydrates you eat and vegetarian diets are almost always higher in carbon hydrates anybody knows this I was a vegetarian for over 20 years I avoided meat red meat butter cheese everything like the plague and when you're not having meat for dinner or you can't have an egg pie you're having pasta grain-based meals you're having cereals you're you're used to bake my own bread you have a high carbohydrate diet and that drives up your triglycerides and that is another sign of your worsening cardiac risk so at all this is a mixed outcome a mixed grade for vegan vegetarian diets and heart disease what about diabetes this is the latest consensus statement that came out of the American Diabetes Association which has always been hostile to low carb diets but it's come out saying for the first time we believe that low carbohydrate restriction is really the best is the best course that you can take and it it said that there was not ample evidence particularly for a vegan or vegetarian diet and that those diet showed a fairly small ability to reduce your average blood glucose measures which is called hba1c I just want to go to this this is one of the meta-analysis they cited this is the bigger of the two that they cited there were only two that were available and you can see here this is David Jenkins who's a vegan vegetarian who is said has on the record is saying he thinks everybody should be vegan vegetarian this person is somebody who works with an animal activist group so I just want to show you that there's this is one of the reasons that we're all so confused there's a lot of bias in the literature but even they could find oops even they could find very little evidence of any kind of benefit from a vegan vegetarian diet for reducing diabetes again that blood glucose decrease is only 0.29% by contrast sorry I have to go through this all again a recent low carbohydrate trial after one year found a six point three to seven point six percent reduction that is just I mean compare that to 0.29% reduction and and you know low carbohydrate diets are not always high in animal foods but they are definitely it are definitely much more common contain animal foods so that really sort of blows away really any other diet what about non alcohol aholic fatty liver disease a rising epidemic we're not sure exactly what causes it may be too much fructose but you can see that the diets from this review paper the diets they single out are either Mediterranean or paleo as being viable ways to combat that disease but not again a vegan or vegetarian diet so what are the arguments that dr. Katz uses when he's defending his his point of view he often talks about the blue zones the blue zones I don't know if you know them that came from this book it was the author went around the world and found what he thought were the longest living people and he who wrote them up in his book I actually have this book at home and I looked at it for the first time just last week when I was preparing for the debate and it was stunning to me that there's no footnotes in it so you really can't check anything so it is surprising to cite this as your primary resource it's because you can't look anything up but one of the blue zones is one that we all know really well which is the Okinawans who are reportedly supposed to live very long and do live there is a cohort that has been very very long-lived but I mean just to give you an example of why it's so hard to trust this kind of evidence because they did a dietary sample of these people in 1949 when the island was had they just Japan it just lost world war two the island was occupied by US soldiers they were not they were barely feeding their prisoners and they and and over 80% does it say over 80% had symptoms of being malnourished so when you go into a population you have no idea what these people ate when they were young or as teenagers or for the rest of their lives I mean you have no idea what made them long-lived you can't say it was their diet in 1949 that was an exceptional sample here's another this is another sort of study that dr. Katz likes the site of the Tasmanian people in Bolivia he also plant-based diet I just wanted to look at that study a little more closely today had very low calcium scores it's a sign of heart disease and if you but if you look at their diet it turns out there's no pay there's no information on diet in the paper it could they refer to another paper where the diet was taken on only breastfeeding woman and that paper says that 83% of the women are having meat every day how am I getting it right fish every day and 63 percent said having meat every day and even that paper sort of then cites another paper which you know so you're three degrees removed now from getting the real dietary data so a very tenuous kind of data I just want to give you one example I mean it's like you know you can cherry-pick certain into these dimples but there are so many counter examples this is a study on 1 million men in India where the southern Indians eating mostly plant fats had were heart disease rates 7 times higher than the northern Indians eating 8 to 19 times more fat mostly dairy fat and the southern Indians died 12 years earlier so I can't go through all my examples now because I'm running out of time but here's just a couple of other facts that contradict this idea that eating more plants will protect against disease we eat 44 percent more plants foods today than we did in 1970 I took sugar out of there because I didn't think that was fair but it's still is not saying they caused these diseases but they have done a terrible job of combating them let's just say that and here's animal foods you can see whoops animal foods I'm sorry all gone down while obesity and diabetes have increased so it's very hard to make argument that these have caused those diseases what else do you have to ignore in order to believe that vegan vegetarians are are the best for health all of human civilization right I mean ever since you are young we I mean ever since the humans that have been young we have eaten meat and dairy and it's in all of our art it's everywhere a british captain navy surgeon captain is as quoted as this one my favorite quote saying it's just ludicrous to believe that a modern diseases could be could be blamed on an old-fashioned food this is just a timeline of history I mean you'll see this is where at the very end here we start to get access to fruits and vegetables year round it's only possible because we had we fly them in by plane and train and automobile I mean people sitting in this room right now in May we would be like struggling there'd be no more moldy apples in the barrel there'd be no more root vegetables we'd be waiting for June to get our next fresh fruit or vegetable so it has only been possible in the last you know a few decades that we've been able to eat fresh fruits and vegetables year-round so all of these facts contradict the idea that vegan vegetarian diets could be superior for health and now just a quick word about saturated fats which are not only in meat but in food dr. Katz likes to say that saturated fats he believes they still cause heart disease these are some of the most tested fats in the world huge clinical trials on 25 thousand people and most of them in patient therefore highly controlled and the results are having no effect of saturated fats on cardiovascular or total mortality just none so this hypothesis has been tested more than any hypothesis in the history of nutrition and disease and the results have been null this is a chart you're just gonna have to take a graph a picture of and I can explain to you later but it shows that for all the hard outcomes death and cardiovascular mortality all the review papers find no effect of saturated fats okay I've got a minute left so I'm gonna skip all these slides and just say this is the state of evidence on the vegan vegetarian diet it remains a hypothesis it has not been rigorously tested in in randomized controlled clinical trials human evolutionary history does not support it and there was a great deal of contradictory evidence so it is now incumbent I think upon dr. Katz to show that there is indeed rigorous clinical trial evidence that supports the idea that vegan or vegetarian diets are superior to health then diets with animal foods thank you very much thank you Nina dr. David Katz arguing for the negative take away James gene Brett thank you thanks very much gene okay good evening folks so this exactly this and only this is what we all agreed to see debated here this evening this is the resolution there is little or no rigorous evidence that vegetarian vegan diets are healthier than diets that include meat eggs and dairy the first person that I invited to join me here this evening after my wife who's here as well as two of my Brooklynite daughters was Mark Bittman this was because mark and I did a couple pieces together recently in New York Magazine on diet and health trying to make sense of the science and we're writing a book together now and it's nearly done and I thought it would be helpful for mark to sit in and listen to this exchange but mark wrote back to me right away and the enviable bastard said I can't come I'll be in Bermuda I don't know that these guys are in Bermuda but they're wearing Bermuda shorts anyway after telling me I can't come I'll be in Bermuda he went on to say you do realize that resolution is a sand trap and I wrote back and said yeah so how much is little and who decides what exactly is rigorous and who gets to tell whom what is the operational definition of healthier actually these hours are slightly out of place so what exactly are the vegan vegetarian diets we're talking about what is healthier and most importantly in that arrow so we have a formatting issue here but that's supposed to land on include what does include me is that eight times a day or once every eight months so yes it's a sand trap but I knew that coming into it but the the resolution specifically and I didn't choose it I had no input into the wording here I just accepted the invitation the resolution is a negative it asserts an absence of evidence and so while I am trying to demonstrate the existence of evidence my counterpart has to demonstrate an absence of evidence there is little or no rigorous evidence and proving a negative is an impossible standard even if I fail to show you any rigorous evidence there might be some somewhere we haven't proved that there is none and that's the job so John Oliver said impossible to prove a negative so yes this is my situation tonight I readily concede that however I think my counterpart situation looks more like this the job is to prove a complete absence of evidence so we'll see how that plays out I hope these arrows do land in the right place up here so the the issue then we need to discipline is what do we mean by vegetarian gene I think you're in the way if you know thanks what do we mean by vegetarian vegan diets and what do we mean by diets that include meat eggs and dairy and I think we have to discipline the resolution just a little bit because this Plus this is vegan and throw this in and it's vegetarian and I didn't come here to debate this nonsense and I trust you didn't come here to hear this debated it only makes sense to have this debate if we're talking about sensible balanced whole complete reasonable vegetarian and vegan diets and frankly I don't think the debate made so much sense either if by diets that include meat eggs or dairy we need an optimal plant-based diet that rarely includes a bit of venison or an optimal plant-based diet that rarely includes a bit of wild salmon or an optimal plant-based diet that occasionally includes Greek yogurt right I think what we need to compare here is diets that are built out of plants and diets that routinely include meat eggs and dairy and by the way the resolution doesn't say or it says and so I think that's the relevant comparison that's what I came here to talk about now even accepting the invitation under those circumstances I'd like to point out that this is not an argument I think makes any sense at all because there are good and bad vegan and vegetarian diets and frankly I don't necessarily think if we just focus on human health at an optimal vegan diet is demonstrably better than an optimal Mediterranean diet so basically I've been asked to come here and fight left-handed and like inigo montoya I am NOT left-handed but I accepted the terms of the exchange so I will fight left-handed so the resolution again is that there's little or no rigorous evidence that vegetarian vegan diets are healthier than diets that include meat eggs or dairy so again these arrows are falling in odd places so let's agree I'm not sure where that one's supposed to go but I think it's vegetarian vegan diets let's agree we mean sensible complete vegetarian vegan diets healthier let's agree we mean less premature death less chronic disease and improvement in well validated biomarkers that are predictive of those and let's agree that we mean include is routine it's not very rare inclusion of Greek yogurt it's routine inclusion of meat eggs and dairy that makes the debate interesting and then we can shift our focus to the core of it because this is actually not a debate folks about dietary details those haven't really been specified it's a debate about evidence the core of this debate is little rigorous and no so if we accept the resolution as what's being debated here this evening know is wrong if I can show you any little is wrong if I can show you a bunch and rigorous well who gets to decide well there are objective standards for rigorous evidence some were already mentioned here this evening grade is a scoring system for systematic reviews most of the scientific community signs off on the fact that meta analyses systematic reviews and randomized control trials are at the pinnacle of evidence BMJ pretty much agrees with this they have their own spin on it the Center for evidence-based medicine at Oxford University pretty much agrees but since I am obligated to stand up here this evening and defend to you this notion of rigorous evidence I thought we should voir dear me I'm essentially the expert witness right am i qualified to say I think evidence is rigorous so I have been asked to do review articles on diet nutrition for the peer-reviewed literature I've authored multiple editions of a leading nutrition textbook for healthcare professionals used in medical education I've co-authored multiple editions of a leading epidemiology textbook v is in production right now this has been translated into a bunch of languages I'm not sure what all these languages are to be honest with you written a textbook on evidence-based medicine I'm going to talk to you this evening about randomized control trials I have conducted and published these multiple times I have control trials I'm going to talk to you about systematic reviews I have conducted and published these I'm going to talk to you about meta analyses I have conducted and published these and I have invented research methods we'll talk about research methods I've actually invented methods of evidence synthesis most notably evidence mapping this goes back to 2003 this is a widely used measure to assess the quality of evidence in diverse medical fields we actually have a new invention related to evidence synthesis called helm hierarchies of evidence applied to lifestyle medicine this paper is currently under review at medical research methodology so I have to show you some evidence to refute none I have to show you a bunch to refute little and I humbly submit that I'm well qualified to adjudicate rigorous but particularly if I cleave to objective standards like for example randomized control trials so let's just talk about randomized control trials of vegetarian vegan diets and as I do this and I pull up these text boxes so significant reductions in lipids and inflammatory markers with the portfolio diet that's a vegan diet every one of these randomized control trials I'm about to show you compares a vegan or vegetarian diet to an omnivorous diet and in every case what's in the blue box is verbatim from the paper so I'm not editorializing here so basically a vegan portfolio diet lowers lip is as effectively as a statin and the omnivorous counterpart diet did not work as well this study shows that a vegetarian diet was more effective than a non-vegetarian Mediterranean diet at lowering LDL cholesterol this and again all randomized control trials of various sizes cardiovascular risk reduction was optimized by a heart high carbohydrate meaning a high plant food by the way carbohydrate is plant food all plant foods or carbohydrate sources so there was a better effect on lowering cardiac risk markers with a plant-based low glycemic diet than a meat-based low glycemic diet and against a little hard to see from this angle so forgive the turning TMAO is trimethylamine n-oxide it's a potent atherogenic metabolite this randomized trial of multiple diets showed that the only way to reduce TMAO was to take meat out of the diets and when meat was replaced with plants TMA plummeted this randomized trial shows that a low-fat vegan diet improved glycemia and plasma lipids more than conventional diets recommended for diabetes by the American Diabetes Association this randomized trial showed improvement in insulin sensitivity beta cells are where insulin is produced through a low-fat plant-based diet compared to an omnivorous diet this randomized control trial showed that reducing saturated fat intake is associated with reducing intrahepatic fat fat in the liver leads to insulin resistance this was really interesting it was an over feeding study saturated fat produced more fat in the liver than over feeding the same number of calories from sugar or anything else this randomized control trial compared it was a feeding study basically a hamburger versus a vegan meal of comparable calories there was impairment in got hormone responses and increased oxidative stress after the hamburger but not the vegan counterpart this randomized control trial shows vegan vegetarian diets all better for reducing the dietary inflammatory index of potent mark of chronic disease risk this cart this randomized trial shows in patients with coronary disease a vegan diet lowers high sensitivity c-reactive protein a potent inflammatory marker this diet shows that dye quality scores increased significantly on a vegan diet but not counterparts that's important because these diet quality scores the HEI alternate healthy eating I realize this is a lot I'm sorry these in turn correlate with all cause mortality cardiovascular disease cancer type 2 diabetes this randomized trial shows greater weight loss in the vegan group compared to the omnivorous group this randomized trial shows more again weight loss compared to an end SEP that's the National cholesterol education program this randomized trial shows plant protein produces particular improvements in body composition during weight loss this study showed that plant-based protein is good at controlling hunger and satiety as animal protein during a weight loss experience another randomized trial reduction intramuscular fat with the vegan but not the omnivorous diet another randomized trial mean BMI reduction greater with whole food plant-based these researchers go on to say they think this is the greatest weight loss seen at six and twelve months when you aren't specifically restricting calories another randomized trial perhaps the most famous Dean Ornish randomized trial patients with coronary disease this was a randomized trial de novo people realize this but here a plant-based diet caused actual regression of coronary atherosclerosis that's shown on top the bottom images are PET scans they show cardiac metabolic function the orange is normal leftist before right is after the lifestyle intervention with a plant-based diet these images show the effects of the same plant based diet area intervention this is from the Cleveland Clinic and the orange study went out five years and at five years the folks who had this plant based diet intervention they had further regression of their coronary plaque the control group had twice as many cardiac events that's mi sudden cardiac death admissions to the hospital for heart failure and we don't need to decide that this is rigorous evidence the Centers for Medicare and Medicaid Services have already done that for us they've concluded that this program meets the intensive cardiac rehab program requirements set forth by Congress and Medicare reimburses for this program of plant-based nutrition as cardiac rehab and as an alternative to coronary bypass surgery this interesting randomized trial shows improvement in mental health with a vegan diet as compared to omnivorous controlled right depression anxiety etc this was a multi-site intervention at work sites this is just a sampling of randomized control trial there are many more it's already too much to show you I apologize for the pace of this but it's the nature of the enterprise now let's look at systematic reviews and meta-analyses I'll go through these very quickly so these are exclusively meta-analyses systematic reviews most of them are meta analyses of randomized control trials some of them are meta analyses of cohort studies and some a combination of the two so there is some variation in the mixture I'm just trying to carefully watch the time so this shows an association in meta analysis between vegetarian diets and lower blood pressure than with omnivorous nights omnivorous diets of course diets containing meat eggs and dairy are the control in every instance this meta analysis shows vegetarian is associated with lower levels of high sensitivity c-reactive protein this meta analysis shows reductions in multiple markers of inflammation including c-reactive protein fibrinogen leukocyte concentrations this meta analysis shows lower mean concentrations of serum cholesterol on vegetarian vegan diets another meta-analysis substituting meat with high quality plant protein associated with favorable changes in blood lipids and lipoproteins again these are mostly meta analyses of randomized control trials another one vegan diet is associated with more favorable cardio metabolic profile another meta-analysis the portfolio diet reduces the 10-year risk of coronary heart disease this is a vegan diet another meta-analysis vegetarians have significantly lower scheme at heart disease and mortality another meta-analysis lower risk of colorectal cancer in the vegetarian and vegan diets another meta-analysis inverse association with vegan diets and diabetes risk another meta-analysis diets that produced the highest scores the these various measures of diet quality have the lowest levels of all cause premature death cardiovascular disease etc and the highest score on these measures is a high quality vegan diet and another meta-analysis significant protective effect verses the incidence and mortality from ischemic heart disease and cancer okay just a sampling all right it is just a sampling all right now I want to argue so I'm a scientist I've done this my whole life I want argue that although these are the objective standards of high quality evidence I don't know that they necessarily are the most robust evidence but let me first ask you a question how many of you would agree that in order to know something is true not believe it's true or wish it's true or hope it's to know it's true you need evidence that it's true to know something's true it's a little hard to see right to know something's true you need evidence is true and how many of you would agree that to know something is true with a very near certain level of confidence you need rigorous evidence that it's true you're being cautious right you know something with near certainty can you note when you're certainty without evidence okay how many of you know if I toss this Apple up be honest it's gonna fall back down and not float away so I guess the evidence was very strong was it a randomized control trial was it a meta-analysis see I think science is being abused and misused I think the most robust evidence is remarkably consistent patterns at massive scale on obvious display and so frankly we can know a lot from observation yes we need randomized control trials to populate gaps and later in the evening if there's time I'll tell you the specific role of RCTs they are not the be-all end-all they don't answer every question so you knew what was going to happen in this Apple it's just the consistency of the pattern so yes I will talk about the blue zones because there are five identified blue zones where people live to be a hundred and don't get chronic disease and they're very diverse but if we were to plot their diets on a scale from animal food predominant to plant food predominant they would cluster at the plant food predominant in they range from mostly plants to all plants and yes that's important and then there's a lot of other evidence so gene expression a vegan diet has been shown to upregulate genes that protect against cancer this is a whole body of literature all in its own vegan diets and lifestyle interventions have been shown to grow telomeres the caps at the ends of our chromosomes that correlate with our longevity the higher the intake of dietary fat from animal sources to hire the all cause mortality the higher the fat in our diet from plant sources to lower the all cause mortality exactly the same with protein more animal protein more premature death more plant protein less premature death and frankly the observational evidence just goes on and on and I'm not going to characterize all these right enough enough because my only job is to show you that there isn't no evidence and there isn't little evidence and a lot of this evidence is rigorous so on and on and on and on and on Lancet study 195 countries more premature death all around the world with more intake of highly processed food which is also bad not all plant food is good obviously but more meat and processed meat lower rates of premature death around the world with more intake of vegetables fruits and whole grains copy that the common denominator in all of the literature on lifestyle interventions is plant-based nutrition and while you may think I'm showing you lots of studies tonight actually I can't I can only show you a small sampling because there's just too much literature on this topic it just goes on and on and on and on and on and on and on so there is little or no rigorous evidence that vegetarian vegan diets are healthier than diets that include meat eggs and dairy well or no is clearly wrong because there's some little is wrong because there is a [ __ ] whack and for those of you who are quantitatively punctilious a [ __ ] whack is 1.2 American shitloads and it is objectively rigorous evidence including but not limited to multiple RCTs meta-analysis systematic reviews thank you [Applause] so now we're gonna get the two rebuttals you'll be ready for your questions and I just wanted clear in terms of way I do things is yes I wrote the resolution but both sides are given the opportunity to read and improve the resolution and indeed both sides did and I'm now bringing Nina for the for her rebuttal and okay well there's obviously too many studies to even respond to here but let's let's start with the Apple okay so every study that dr. Katz showed you after the Apple was an association study that means it's an epidemiological study that means the odds that those studies would be correct are 0 to 20% I just want you to remember that it is it is 0 plus 0 plus 0 plus 0 is still 0 no matter how many of them there are when he was going through before the Apple the systematic reviews and the meta analyses I counted 11 of them he showed us 10 of those were on observational epidemiological studies again zero plus zero plus zero plus zero a lot you can show a lot of slides a lot of data but if it's not reliable is the tragic the tragic problem of data not being able to prove cause and effect and we've seen we've seen it through hormone replacement therapy we've seen it through our being told that we should not eat cholesterol and avoiding eggs and avoiding you know egg yolks and shellfish and then that being wrong those are the tragedies that happen when you rely on lesser evidence you cannot add it up and have it be anything more than what it is which is unreliable zeros I like the point about the Apple I think it's clever aid is true we should trust our senses on certain things and what do we see when we look around us in America today we see out of control epidemics of obesity and diabetes and heart disease and cancer and fatty liver disease that is what we can see with our own eyes without anybody telling us and we have since 1970 been eating more and more and more plants food and fewer and fewer and fewer animal foods so that is something that just is some an observation we can all see we have tried really hard to follow these plant-based more green guidelines and that has not worked out for us I want to just there's a number of clinical trials that dr. Katz did show before he went on to the systematic reviews and meta-analyses and I think that one thing that's really important to say is that the reason that you look at meta-analyses and systematic reviews is that they are able to sift through all of those clinical trials and make judgments about them many of those clinical trials that he cited you know some of them aren't randomized some of them are you know a cholesterol-lowering diet is not necessarily a diet that's a vegan diet or you have problems there are all kinds of criteria that go into deciding whether a clinical trial is a good trial and and should be included or as not does not meet your adherence standards that is why I only presented reviews by credible bodies and I only presented systematic reviews of randomized controlled clinical trials and so even as I said when the dietary guideline committee went around to looking for it's it's it randomized controlled trials for the vegetarian vegan diet they couldn't find any okay one final note on the Ornish trial which is the one that supposedly showed the progression of heart disease that was one trial on 41 men who were put on some of them were put on his vegetarian diet it was a multifactorial intervention so anything it was included cessation of smoking and more exercise in yoga and meditation and supplements so you don't know if there were good outcomes if as he said if if that was due to the diet or any of these other interventions on his trial the good cholesterol HDL declined as it always does in a vegetarian diet was a sign of increasing cardiovascular risk on his trial two people died in the intervention group versus one in the control group which is something he doesn't often advertise but that is a well in certain parts of the nutrition world oh you call that a 100% increase in mortality so another you know I can't go through all the trials that he showed were by Neal Barnard who is an animal rights activist who starts with the point of view that we should not be eating animals at all and that is his starting point scientifically and his study that he when he showed TMAO which is something he said he could only fix by eating less meat actually it's much much higher in vegetable so reducing vegetables is better for reducing TMAO I just want to say it's just a very highly selective group of trials there and you really have to rely on review papers that have done a good job of weeding through good and bad trials and when you do that you find there's little or no rigorous evidence for the vegan vegetarian diet [Applause] so to be clear bread I'll count on you to get get us started here to be clear you know nobody advocates for eating junk and actually there's been no increase over time an intake of fruits and vegetables in the United States so you know if we're talking about multicolored marshmallows as part of a complete breakfast yeah that's gone up but there's more than one way to eat badly and again bread if we got the slides you got him here okay so what we're debating and by the way all the trials I showed you were randomized control trials and you know I don't know if anyone here gets to decide okay was a randomized control trial but I didn't like the author so it doesn't qualify as rigorous evidence I don't think it works that way so they were all randomized control trials and most of the meta analyses were of randomized control trials and as I mentioned some included observational studies so this is the resolution again but are there studies that can show that eating meat is better and how is that even possible what if vegetarian vegan diets or plant predominant diets are unquestionably better how can how can it ever look otherwise well there are three reasons comparison conflagration and context comparison is key this study by Lee at all looked at a hundred thousand people over 30 years and then carved out the ones who reduced their intake of saturated fat from meat and dairy and asked the question that is routinely neglected what did they eat instead well if they substituted refined carbs and added sugar it was a sideways move they're the same rates of heart disease there is more than one way to eat badly and the American public is committed to exploring them all that's sort of the takeaway message here to say seriously okay however if they replaced saturated fat from animal sources with unsaturated fat from plant sources rates of heart disease plummeted if they replace these calories with whole-grain calories rates of heart disease plummeted right so the instead of what question comparison is key the other issue is conflagration it's so easy to create a straw man and then set fire to it so a lot of these studies that suggest eating meat is good well I told you I don't think we want to talk about the cocoa cotton-candy vegan diet but some people do and so a lot of the studies you hear about this was a randomized control trial we randomly assigned people to an omnivorous diet in a vegan diet you think bias doesn't figure into that and by the way the fact that you can hear these randomized control trials were biased well that's that's a precaution that's universal right ah so they can be biased so maybe we need other forms of evidence too because if this is the vegan assignment it's a straw man and if this is the vegetarian diet it's a straw man and then context is key sometimes eating meat is a really good thing this poor child has kwashiorkor it's protein deficiency this doesn't happen in the US but it still happens in the Sudan and other places around the world what is good to eat is totally dependent on epidemiologic context we eat too much meat eating more vegetables and fruits and whole grains beans lentils nuts and seeds would be better because of the nature of our diets and the nature of our epidemiology but no amount of evidence regarding the existence of B evidence say for meat can prove the non-existence of a and again my job here was to argue there is a [ __ ] lack of rigorous evidence supporting vegetarian vegan diets as in fact there is now there's debate about what constitutes high-quality evidence we could spend time going into the weeds here but I'll simply tell you for now our CTS have both strengths and weaknesses there is no single definitive source of high-quality evidence but no we're not clueless about the basic care and feeding of Homo sapiens if we were if our science were really as useless as some content we'd have no basis to know whether jelly beans or pinto beans were better for us science is a set of tools they can be used well or badly and frankly we spend a lot of time using tools badly I do RCTs they have limitations we have no RCTs to prove the harms of smoking and it was the merchants of doubt from the tobacco industry who made hay with that for years you don't always need RCTs and you can ask bad questions like which step in a long hike is the active ingredient we don't do that in exercise research we do just that kind of silly thing in some nutrition research I don't know why but it does get done so frankly we have an aggregation of diverse sources of evidence they all point in the same general direction plant predominant to plant exclusive diets produce more years in life more life in years there isn't no evidence there isn't little evidence there's a lot of evidence and much of it is rigorous by absolutely any standard thank you David and we now go to the Q&A portion of the of the evening so please line up with your questions at any time if either of you want to ask each other question you can do so I want to start promoting the moderators prerogative and ask you each a question question for you new titles is there any sort of evidence that you say is rigorous is there any controlled rigorous trial randomized trial evidence that you could cite on behalf of your contention having to do with meat any evidence that you could cite that that that meat diets are are healthier than plant-based diets yeah I mean there's quite a bit of clinical trial information on I mean anytime you compare a diet that has some animal foods in it to a vegan or vegetarian diet and that has there's only a handful of those studies where they do compare them depending on it really depends on that outcomes but there's there is and especially if you are if it's meat and animal foods and it's high-quality and they're reducing carbohydrates they always perform better in terms of their cardiovascular outcomes their weight-loss outcomes their ability to control glucose control that's why you see the American Diabetes Association selecting that though that dietary pattern so the clinical trials on meat specifically are there's two systematic reviews of clinical trials on meat that I know of that show that cardiovascular outcomes are improved one of them looked at 0.5 ounces or servings of meat per day and showed increased benefits cardiovascular benefits for eating the meat versus not eating the meat and there is one other review on cardiovascular outcomes that also showed that meat was beneficial looked better for cardiovascular outcomes thank you David you want to comment on the question under the answer well at least peripherally so you know again I think we established at the beginning and both said very similar things about what constitutes rigorous evidence I get the sense that's been turned into a slippery slope it's rigorous unless I don't like the study you know I think we ought to honor the standards that in play what I'd like to refer back to Jean if I may is the fact that I'm fighting left-handed here this evening and I am NOT left-handed so my fate many of my favorite long-term randomized trials are about reducing meat intake so you know again vegetarian vegan diet studies is a very small slice how do you improve the health of a population that eats too much highly processed food and gets an excess of saturated fat by the way that's a simple-minded notion that saturated fat is bad you know what's bad imbalance is bad if you had no saturated fat in your diet added some it would be fine if you already have too much and add more it's bad we're just prone to an excess one of my favorite studies this is a multi-country randomized control trial is the Leone diet Heart Study this was a randomized trial throughout countries of Europe where people who had already had a myocardial infarction were randomly assigned to their customary diet so in northern European diet which by the way is much better than the typical glow-in-the-dark junk lead here in the United States so it wasn't optimal but yeah it wasn't all frankenfood either and the intervention diet was a Mediterranean diet that systematically shifted them from animal foods to plant foods and shifted their fat intake from the saturated fat that's concentrated in meat and dairy to more unsaturated fat notably the oleic acid that predominates in olive oil but also fat from nuts and seeds avocado fish and seafood in lieu of beef and terrestrial animals and there was a 70% reduction in the rate of recurrent MI over the multi-year span of the study really quite stunning now I couldn't cite that this evening because I was box into vegetarian and vegan but the bigger argument here is what would improve your health what would improve the health of the American public is it eating more meat eggs and cheese or is it eating more fruits and vegetables and the evidence there is overwhelming and frankly incontrovertible that it's eating more fruits vegetables whole grains beans lentils nuts and seeds but you do you do advocate the plant-based diet though well I advocate a diet that's mostly you're asking my you know that wasn't that wasn't the resolution well I think well into the prevention but I personally advocate diets for human mostly plants yeah yeah diets that are mostly comprised of minimally processed whole fruits vegetables whole grains beans lentils nuts and seeds plain water one thirsty yeah you penny you wanted to comment Nino asked that David a question yeah oh yeah I just want to respond to just a couple of things that are inaccurate the lion for so the Leone diet heart trial it was it was not a multi-country study it was only in Lyon and it was specifically to look at a kind of margarine they had made up Thai was was linoleic acid and they and it was a study where they did very little it was very poor in terms that there was actually very little difference between the two groups in terms of the dietary intake and it was it was not a study looking at a plant predominant versus a more animal predominant was mainly to look at this effect of this margarine that they were interested in because they were interested in the so-called Mediterranean diet with olive oil but I want to also increased it just correct two other things you said when you said we haven't increased fruits and vegetables in this country since 1970 we've increased our consumption of fruits by 35% and our consumption of vegetables by between 20 and 25 percent and that I went to look into that because I was curious like you what are they talking about do they mean ketchup you know neither of us I think are talking about or in good faith about a junk food vegan diet and actually the greatest increase in vegetables that we eat a four hundred and thirty three percent increase is in leafy greens that Americans are eating more of which are supposed to be the kinds of vegetables that we're supposed to eat and there was nothing so we do eat more fruits and vegetables and just a final thing I want to correct is this idea that saturated fat is synonymous with meat the foods that are the highest concentration in saturated fats are plant foods that's coconut oil and palm oil we use we have a lot of us we all eat palm oil in all of our packaged foods that's where we we get they're all made with palm oil because the stable fat so it's it's incorrect to say that saturated fat is synonymous with red meat and or in dairy it's just in act well let's set aside the saturated fats cuz yeah I wanted to actually needed to the question I I wanted to put to you David reject which is has come up which is only this isn't there evidence that that there has been noticeable improvement in him in in the American diet per capita consumption of meat is down per capita consumption of sugar is down but capita consumption of fruit and vegetables is up so are you saying there's been no improvement or do you not do knowledge that there has been data showing a tangible statistical improvement and if so wouldn't you want to look for tangible improvements in health as a result of that improvement that's my question okay but but first everything we just heard about the Leone diet Heart Study is inaccurate and you're gonna have to pull the papers yourself from the peer-reviewed literature to check that out please refer to the period and then we'll follow up and then let's address the question so there has actually using the objective measures of diet quality over very recent years and and thank goodness and frankly people I think it's because we've run out of new and innovative ways to eat badly there has been a slight improvement in diet quality I think part of what is fueling that is at long last an interest in this notion of Whole Foods and the idea that the less processed the better and and so there objectively measured there's been a very slight improvement in diet quality this was reported by the same unreliable folks at Harvard that are responsible for a lot of the research we heard is useless but I guess we trust them when we like their outcomes so there's been a slight a slight improvement in measures of dye quality I've looked at data from n Haynes which is the national health nutrition examination survey conducted by the CDC I cannot find evidence there that we have increased fruits and vegetables as a proportion of calories if we qualify refined grains as a source of vegetable intake obviously that's gone up if we think of fried potatoes as a vegetable and by the way ketchup and marinara sauce on a slice of pizza qualifies as vegetables under the US federal guidelines so theoretically and we're told we're increasing our intake of vegetables a lot of its that that the other important thing is that the entire food supply is booby-trapped to be addictive Michael Moss a Pulitzer Prize winner has written about that and so our total intake of food has gone up and total calories have gone up and by the way our total intake of fat never went down it's just that fat as a percent of calories went down a little bit because our total calorie intake went up and this is pretty well documented again by Ann Haynes and others so no no no per capita I thought it happened a reduction in consumption of red meat and per capita consumption of sugar yeah well sugar has been going up sadly until quite recently it's threatened a little bit red meat has gone down and we have shifted from plant-based from from animal-based fats to plant-based fats so two quick comments about that and then I'll wrap up so you know frankly yes there has been a slight improvement in diet quality and there has been a slight decline in the rates of major chronic disease in particular cardiovascular disease associated with this trend to eat a bit less meat and eat a bit more animal products plant products however this issue of saturated fat from multiple sources is true historically we got our saturated fat from meat and dairy as people cut back on meat and dairy sadly they don't start eating more lentils and broccoli they start eating highly processed food made with palm oil which is a highly saturated tropical oil may be better than animal fats for human health but that's very contentious probably not and frankly quite devastating for the rainforests in Borneo which are being cut down to make palm oil plantations and ultimately that's bad for us too so yes sources of saturated fat have shifted over time but historically the preponderance of saturated fat in the diets especially of Americans has been from meat and dairy yes their saturated fat and coconut but come on folks how much coconut do you actually eat right I mean so it's just not a major source it is a source it caught on as a popular cooking oil for a while and then the blush is off that rose but most of the saturated fat in the American diet has historically been and frankly remains meat and dairy okay questions from the audience uh please I don't see you out there but if no you have to be online at the mic go down there okay please state your question has a question don't tell us who you are just ask your question my questions for dr. Katz how does your diet deal with the presence of anti-nutrients implants like oxalates phytates etc excellent question so again this is not my diet I'm not sell selling any diet here I you know I'm here talking about plant predominant and plant exclusive diets because that's the resolution we agreed to so you know that they're there a lots been made particularly by this guy Gundry who wrote the plant paradox and there are anti metabolites in plants and in particular he talks about lectins but we could pick anything else out right so you mentioned several others you realize that oxygen is one of the more potent human toxins known you know that if you breathe pure oxygen you'll be dead in about 72 hours it's a real problem when we're taking care of patients in the intensive care unit I'll spare you the gory details but titrating oxygen can be a real challenge so therefore there is an anti respiratory breath see who cares okay so pure oxygen is toxic there's oxygen in the air actually some of its good for us and we need to breathe so really the question is what happens to people eat the foods I think one of the great tragedies in all of this discourse on the topic of nutrition and human health is the fixation on isolated parts as opposed to the whole people don't eat nutrients they eat foods what happens to people who eat a diet rich in vegetables fruits beans lentils beans and lentils legumes in particular concentrated sources of these lectins that Gundry tells us to fear in intervention trials and at the level of whole populations observed over generations and if I may just for a second quickly you are not going to have ever a randomized control trial that tells you what happens to somebody over their entire lifespan you cannot randomly assign newborns to a diet and expect them to adhere for 280 years if we don't derive some of what we need to know from observational epidemiology most of what is most important will never be known what happens over entire lifespan does this add years to life does it add life to years but both intervention trials in the short term randomized control trials meta-analyses population studies observational epidemiology and ethnography of entire populations over the span of generations which no RCT can ever do show that these foods with remarkable consistency pretty much that much consistency are associated with more years in life more life in years so who gives a damn if they're anti metabolites in the food please my question is also for dr. Katz when observing the different trials specifically comparing the omnivore diets to the vegetarian vegan diets I can't help but wonder when looking at the the meat products and the dairy products that the omnivores were eating was the quality control as far as the processing goes ergo another way to ask the question is for the vegetarians and vegans eating very high quality plant products and meanwhile the omnivores we're eating McDonald's burgers and other very highly processed foods that are just generally unhealthy thank you for a beautiful question insightful honest and and what I can tell you is sadly and and you know this is this is why no we cannot rely on any one study and no single RCT will ever give us definitive truth and in science what we rely on is the weight of evidence from multiple sources and this kind of careful looking under the hood is required so I pointed out to you from the perspective that I'm arguing this evening the danger of a straw man right so if I want to show that eating meat is better than a vegan diet all I need to do is to dine it design a study of a truly awful vegan diet so coca-cola and cotton candy is the vegan diet and frankly anything's better than that exactly the same in the opposite direction so if you are a vegan ideologue you can design an RCT that compares that to a really bad never study I tried when I curated RCTs that I showed you here this evening to select studies of high quality and even if the researchers were biased to look at the details of the methods to make sure the methods weren't biased that they didn't set this up so in many cases the comparison diets I showed you were the National cholesterol education program recommendation so it's a high quality omnivorous diet the American Diabetes recommendation high quality omnivorous diet and and a high quality Mediterranean omnivorous diet compared to a vegetarian version so I think it's a it's a really good question and a universal precaution RCTs as valuable as they are and again I've made my career for the last 20 years running them they are subject to the bias of the investigator and they only ever ask answer the question you asked and if you want to show that an omnivorous diet is bad can you design into your study a bad omnivorous diet as the comparison absolutely so you really have to look very carefully at that and and again I think what it means is look at a diversity of methods look carefully at the details of studies and only base your conclusions on the overall weight of evidence which is what I've tried to do throughout my career any coming from you Nina no no and yeah I mean I just think that you know when you flash through that number of clinical trials without anybody being able to read them or under see them there's no way we can be assured and you're arguing one side of a debate we have no assurance that that you were actually are curating those clinical trials in a way that would be at all fair the one clinical trial that you went into any depth on which was the Ornish trial we saw quite clearly if upon inspection was was not a it wasn't did not show what you had said it showed so I think that it's very hard to I would I would assume is the audience that's not necessarily trustworthy that some like you know a very a rapid-fire list of clinical trials that you've curated was a fair curation question yeah this is also for dr. Katz you had actually mentioned the in Haynes data that you had looked at a little bit earlier I was fortunate to actually get a hold of it and I was especially interested in how those people above 50 seemed to have a higher rate of death per year if they had lower LDL relative to those who had higher LDL and in fact this even includes the centenarians of the in Haynes data set which I found to be quite interesting much of the data that you were presenting from earlier have a lot to do with the presumed positive effect size of a vegan diet in how it lowers LDL did you have a comment for that sure thank you so to be clear you know and frankly I can't argue about the rapid-fire presentation of clinical trials the resolution is about the existence of evidence I had to show that there's a bounty of evidence and I wish there had been more time to go into detail and routinely I do that but that's not what tonight allows for a reduction in LDL with these plant-based diets was just one of many effects all of them lined up in a direction that's favorable and by the way it's now widely accepted in the cardiovascular community that if you lower LDL which is what all of the prescription drugs approved by the FDA for the treatment of dis lipedema and coronary disease do that what happens to HDL isn't important if you get LDL low enough HDL ceases to be a meaningful predictor at all but my answer to your question is reverse causality we actually published a paper many years ago about the unreliability of cholesterol levels when we admitted patients to the hospital because it always plummets so if people have chronic disease if you look at mortality and lower LDL the question is was there the presence of a chronic disease accounting for the incipient mortality risk and their LDL was falling because of the presence of chronic disease there's a really it's a it's an arduous thing to do in epidemiologic studies to control for that window where you're subject to reverse causality because actually people's LDL is falling because they're sick so it's not that the low LDL is causally increasing their risk of dying it's that their increased risk of dying because bad stuff is happening inside their body and it causes their lipid levels to fall that's pretty well known yeah I mean just say that LDL lowering through drugs is is very different than has LDL lowering through diet has never been consistently shown to be related to cardiovascular outcomes what you do with a drug and what happens with drugs has not been confirmed in diets so the LDL question your doctors putting you on a diet to lower your LDL and he's putting on a drug to lower your LDL the diet lowering LDL through diet is not well correlated with your cardiovascular outcomes each gel is in fact much better correlated with your positive cardiovascular outcomes in diet I'm we have time for one real question take it away please go ahead yeah hi David Katz that was a great presentation I've been a big fan of yours and it's someone's riddle well would you please ask the question you pointed out many common interests many conflicts of interest amongst the vegan authors and the biases associated with that but I've noticed that you're not a physician like yourself like David Katz who spent a lifetime trying to you talk about being the science so do you mind just explaining your financial conflicts of interest like where the money from their books are sold go to and your speaking engagements and things like that yeah I mean conflicts of interest is a super important topic I am I do not receive any money from industry like David Katz I give speeches and I could speak just to all kinds of groups and I just give the same speech to everyone if if if tomorrow at the diet the US government were decide to to endorse a diet higher in in meat and dairy I wouldn't make a single penny I don't I don't profit from from any industry and I'm not I I don't have to share any company I will say it is very distinct from David Katz who who is not only as a CEO and and founder of a plant-based diet company and has a long list of companies in which he is paid for scientific advisers he received more than $750,000 from her she's received more than 2050 thousand dollars from Quaker Oats he's given testimony to defend Chobani the high sugar content of Chobani yogurt at his standard rate of thirty five hundred dollars an hour I mean I think there is a huge number of companies in which he is involved and invested and I will say that I'm not involved in any company or get money from any industry David you want to respond no yes up to you I don't think that's true I actually read a refutation of that in Politico that kind of followed the money trail related to the beef industry in the dairy industry so I think most of what we just heard is untrue to correct that it does not say it says I sat in a room and there was somebody in the room from the cattlemen and that is not anything that I work for them put that in your summary okay you finish your remark David thank you yeah so actually I've not received money from these food companies we've done funded studies and actually all its testimony to I first of all if you are constitutionally opposed to industry funded research you would go into a pharmacy there'd be nothing on the shelves you do realize that almost all drug research is industry funded so the issue is the quality of the research the nature of the contract so my lab over the years has had funding from a number of food companies including a number from the egg nutrition center and as you can hear I'm arguing tonight against routine consumption of eggs but we published a series of studies that found no harm of X including in folks with coronary artery disease the results of the results you don't get to choose so we did an intervention study we used endothelial function as the primary outcome so in in every case where we've had funding in our lab whether it's NIH CDC u.s. industry foundations we've had a hypothesis we've tested it in his unbiased a manner as possible we produce the results and you know as for the rest I I'm not CEO of a company that has anything specific to do with plant-based nutrition I do engage in a number of professional activities that are related to things I believe are important and you know and I think we have to be careful at about hitting one another over the head with this idea of conflict of interest what it makes me think of is there was a time when a group of Republican senators called out Al Gore for having investments in the green economy and gore said yeah and and the idea was he was advocating for these companies because he had investments and he said no I was advocating for these companies and then I invested in them because I thought were supposed to put our money and our effort and our time and our passion where our convictions are okay not the same all right thanks time for the summaries Nina us summation yeah I just want to keep up size 1991 you know I definitely agree that it's great to put your your money in things that you believe in but when you do that to a great extent you are you know and these are some of your conflicts of interest here that when you do that it really becomes it's very hard than to be a credible source for being objective I mean it's it's almost impossible to say well my my opinion comes from my financial benefit or that I might that I might reap our or that it comes from my genuine evaluation of the literature which is why although I have been offered numerous jobs as scientific advisors and and shares and companies that I know will do very well I've rejected them all because I don't want to ever have that kind of conflict of interest you know I think that this is a kind of a nice segue into a you you're an event you're the founder or have been deeply involved in this supplements company and I think that's a kind of an eye and I just want to say that you know other things in which you denied are all on your CV so anybody which is on your website so anybody who wants to go and look at these numbers about how much money you've received from various places can look on your CV that's where I got them so I just like to do my summation I think this point about vitamins and supplements is a really important one well first let me just talk about the clinical whether there has been little or no rigorous evidence that has been presented I would still argue that despite there was incredibly long summary of clinical trials at the beginning because we were able to scrutinize none of them and because other bodies scrutinizing this body these clinical trial data have not found them to rise to the level of being able to endorse them to prevent diabetes to prevent heart disease to to be included in the Dietary Guidelines despite a bias for plant-based diets those bodies did not deem those trials to be rigorous enough this idea that we can then rely on epidemiological evidence because the clinical trials do not tell us everything that we want to know is still just I think a failed concept you know it's this idea that it is hard - yes it is hard to do - to design an airplane but if that's hard but but if you fail in that it doesn't mean that magic carpets fly you know it just means that clinical trials are hard to do they are hard to do but they've been done in the past and they can be done again and they are the only way that you can show cause and effect and again you cannot is the tragic the tragedies of the past where we have seen that we have relied upon epidemiological evidence and gone forward with policies that turn out to be wrong again many women lost a hormone replacement therapy people who gave up and eating egg yolks and and missed out on needed nutrients and I think the last thing that I just want to say do you have my summation sides my conclusion sides oh okay so I just want to say so again just going back to this pyramid of evidence we have not seen randomized control trials in a way that we can speculate that we can understand them and actually evaluate them and understand that they're viable we've only seen observational from you and again this idea that a vegetarian or vegan diet could even be viable to sustain human life these are some of the nutrients that you need to get in order to survive and maybe one of the reasons you're you know a investor or an owner of a supplement company is that you on a vegan or vegetarian diet you must take supplements you must especially take b12 which does not exist in plant foods and many many nutrients and supplements minerals and vitamins that are essential for life are either not available in plant foods or they're in there less bioavailable form I think iron is a really good example of that you cannot get from spinach what you get from meat and that's true in many ways lack of vitamin b12 is extremely dangerous and leads to birth defects so I think that that is just a critical flaw when you're saying let's assume a vegan vegetarian diet which we've only had access to that the last 20 to 30 40 years is something that we can rely upon for the whole human race when it doesn't supply the basic nutrients needed for human life that is a very difficult argument to believe and then again there are these anti nutrients in plant I think a question you kind of brushed off but they're very real they decrease the absorption of iron protein iodine iron zinc magnesium and and and all kinds of so it makes it less possible there are many people who cannot eat these plant foods also you cannot get the long-chain omega-3 fatty acids from plant foods flaxseed oil won't do it so you cannot get those essential nutrients that you need for life from plant foods so I will just say you know you've spoken a lot about your your authority in the field and all the trials that you've done and you know one thing I would say is it's true you've done a lot of this research but it does it's like a sports that there are people who can write about sports and they know a lot more about the sports and the baseball players themselves are out on the field doing it but you know it's a fallacy to appeal to Authority it doesn't matter who is right it matters what is right you're the conclusion while I'm Thank You Brett so while waiting for the slides to be up here actually folks first of all you can know something is true without an RCT but what I presented to you was a lot of RCTs but I want to point out something else that was omitted tonight actually avoidance of hormone therapy because of two RCTs the Women's Health Initiative and the Hearst trial has resulted in an estimated 90,000 premature deaths in women in this country because the data were misrepresented it was a very small increased risk in some women not in others and we've actually scared women who would benefit even in terms of survival away and the correction comes from observational epidemiology we need multiple sources of evidence and by the way you didn't hear me talk about nutrient supplements here this evening all right so not really relevant to the resolution this really is my view in in common with Michael Pollan diets are better when they're real food mostly plants when I reviewed this topic for annual review of public health this was the conclusion that I reached we were specifically told tonight to talk just about human health effects what is the real argument for say vegan diets is it human health effects no I don't know that an optimal vegan diet is better for human health than an optimal Mediterranean diet I think they're pretty comparable frankly they're both massively better than the typical American diet which is the seafood diet i seafood and I eat it but if we look at the trifecta of more years in life more life in years human health ethics and environmental impact which we were told not to talk about this evening that actually makes an extremely powerful case for plant predominant to even plant exclusive diets and frankly this is really important because we are destroying biodiversity on our planet we are changing the climate and all of this we were asked not to talk about so I'm not talking about it except to tell you that for a physician not to talk about it is incredibly irresponsible because there are no healthy people on a ravaged planet and so frankly the impact of our diets at scale on planetary health if you don't think of that as part of your health you are misguided and that was the basic conclusion recently of the Lancet Commission report and by the way the Dietary Guidelines Advisory Committee in 2015 explicitly recommended limiting me to intake and eating more plants and included a vegetarian recommendation based on their review of the literature it was the politicians under lobbying from the beef and dairy industry that expunged that from the official dietary guidelines but this and only this really is what we were asked to debate here this evening a debate is either about a resolution or it's not so if we can change the topic mid debate I'm not sure what I signed up for but I accepted an invitation to debate this issue there is little or no rigorous evidence and I think actually both parties agree that multiple randomized control trials constitute rigorous evidence meta analyses of those trials constitute rigorous evidence so yes you haven't had a chance to read all those papers so there's a bit of a he-said she-said but how was that going to be otherwise unless you became content experts here this evening I presented just a smattering of the relevant evidence but I think it's more than enough to show that no evidence is demonstrably wrong there's obviously a lot of evidence now you could debate whether every one of those trials is completely reliable or not but little evidence is also wrong or is it all good evidence do you like those studies do you like the authors well you folks can take your time and figure that out but there's a [ __ ] lack of evidence that's a simple fact and since the evidence I presented was preferentially randomized control trials meta-analyses and systematic reviews which everyone agrees are at the pinnacle of types of evidence even though frankly I think other forms of evidence are extremely reliable the resolution is wrong thank you I'm Xavier with that that concludes and the the evening's debate and Jane you're opening the voting for the closing vote meanwhile I hope you enjoy this evening and that you can come next month in June the that is next month very different resolution rather dry sounding defended by Professor Teresa girl du chí of the new school will defend the resolution the Social Security system can't add to the federal deficit cannot add to the federal deficit and taking the negative will be me and so I will be debating professor Teresa grilled uchi and guest moderator will be Nick Gillespie so you don't want to miss that and that would be June 17th now events for which we suggest you buy tix right away because we're selling it out will be August 12th the Cato Institute's George Celgene will defend the resolution bitcoin is poorly suited to the purpose of becoming any nation's main medium of exchange opposing him will be Safa tea and a moose author of the Bitcoin standard the decentralized alternative to central banking on Tuesday September 10th part of the problem podcast host Dave Smith the very guy who does our warm-up acts each month will be a debater defending the resolution the libertarian party should never again put up national candidates whose views are similar to those of Gary Johnson and bill weld against Nicholas saw walk chair of the libertarian National Committee Dave a newly a dad is gonna double dip that evening he's gonna be earning a fee as our debater he will also be doing the warm-up act and that evening so that's going to be a double dip from day and Knicks our walk has agreed to that deal so there's no problem from Nick people the Green advance dr. Katz when they come to the wording and everything else which you did you agreed never to speak up what what didn't you speak up yeah you you agree never to speak of the in Vienna there's other things that you agreed never to speak about because they're not run anyway and also the the University Tuesday November 5th another event actually which is gonna involve me once again emeritus professor Richard Wolffe will be defending the resolution socialism is preferable to capitalism as an economic system that promotes freedom equality and prosperity he will be defending that resolution again in that case opposing him will be me and this time I promise not to lose my temper those those who viewed my debate with Bhaskar of occasionally Sun Kerala and socialism occasionally admonished me don't lose your temper again in fact it turns out that I've been told that that debate I did was Bhaskar as a reason podcast has had more viewings than any other reason podcast in history I guess a lot of people wanted to see me lose my temper it turned out but but but it's not gonna happen again not when I debate a professor Richard Wolffe I want to guarantee you of that now as a bonus other good stuff coming up the sella forum will take to the seas from July 5th to 12 Jane I think you're looking at me and I think you have the final vote you can close the voting what the kanto be a contra cruise hosted by Tom woods and Bob Murphy I'll be moderating a sole forum debate on the Contra cruise to Alaska starting July 5th 2 through 12 a pacifist Society is morally and practically superior to 1 using defensive violence it's going to be a defense of pacifism with a Bob Murphy taking the affirmative against Tom woods I'll be moderating that resolution I'll be doing some other presentations on board like this trip to Alaska accompanied by my wife I hope you can all come I got you all a promo if you go into contra cous if you put just put in Soho you can get $100 off the contra cruise and I'll be on board so this could be fun alright now we we have the final vote and let's see thank you voting voting YES on the resolution initially 52% voted YES on the resolution that went up to 57% so that was a 5 percentage point increase so that 5% is the number to beat voting no on the resolution was 16% that went up to 29% picked up 13 percentage points so the turkey roll goes to dr. Katz [Music]

Channel: ReasonTV

Views: 108,137

Rating: 4.7289257 out of 5

Keywords: libertarian, Reason magazine, reason.com, reason.tv, reasontv, diet, vegan, nutrition, carnivore, paleo, carbohydrates, keto, Nina Teicholz, Soho Forum, David Katz

Id: 1qDYl4zHmAg

Length: 91min 38sec (5498 seconds)

Published: Wed May 29 2019

Reddit Comments

[u/oehaut]

The premise of the debate was

There is little or no rigorous evidence that vegetarian / vegan diets are healthier than diet that include meat, eggs and dairy.

I can understand wanting to debate this but I think it was flawed from the beginning and dr. Katz said so too, but for strange reason, although as said by the moderator, he could have changed the resolution, he did not do so.

I would actually agree with the premise as stated, but Katz points about the necessity of defining what are rigorous evidence and who decide what it is, what is a vegan diet and what it is healthier than are important point to discuss.

I think the debate should have focus on what constitute quality evidence, and for what dietary patterns we have the best quality evidence so far.

I disagree with many thing said by Katz and he made mistakes (see later), but since I want to keep this short I’ll state my biggest disagreement of the whole debate, which comes from Teicholz : the idea that only randomized controlled trial are trustworthy evidences.

By arguing that, you’re painting yourself in a corner and putting yourself in a very hard to defense position, because as of now, there exist (to my knowledge):

No randomized controlled trial of carnivorous diet;

Very few high quality randomized controlled ketogenic diet trials;

Few high quality randomized controlled trials of low-carb diet that are not confounded by weight loss and higher protein intake;

No randomized controlled trial of a predominantly whole-food plant-based diet vs a predominantly whole-food animal-based diet.

A big shortcoming of randomized controlled trial is that they are very hard to do for hard end-points (actual disease incidences) since they need to be long enough and this cost a lot of money.

How many low-carb diet randomized controlled trials looked at actual CHD incidences/mortality? None that I can think of right now.

Also, does she holds herself to the same standard?

I don’t have a timestamp but twice in the presentation (edit: first one is at 12:15, can't find the other one), Nina asserts that by lowering HDL-cholesterol you are increasing your chance of cardiovascular diseases.

Are there any randomized-controlled trial that shows that by decreasing HDL-cholesterol either through diet or drugs you increase your chance of CHD? Same for triglycerides? If not, how can she asserts that, by her own standard of evidences? As far as I know low HDL cholesterol as only be linked through observational studies to higher CHD risk.

So, whereas it easy to say : look, vegan diet have very little rigorous science behind them, an easy counter-point to make would be that it’s equally so for animal-based diet. Proponent of animal-based diet right now are mostly using anecdocte and evolutionnary reasoning as their main form of evidences for the diet, since there exist no other. This does not fit within what Nina consider to be good, reliable evidences either.

So where do we look for evidences then?

While the issue raised by Teicholz regarding observational evidences are legitimate, concluding that they are worthless is not a sound conclusion.

Where I agree with Katz is that the is a clear pattern in the scientific literature as a whole, and that it is that, a mediterranean-type diet (so, a predominantly plant-based diet), as of now, as the best support from many different lines of evidences.

An obvious mistake made by Katz that I wanted to point out was that he said that the Lyon study was a multi country study (at 54:31), and Nina correctly pointed out that it was not, and he doubled down saying that it was.

If we look at the paper from the Design section it says

The Lyon Diet Heart Study is a prospective, randomised,single-blinded, multi-clinic (6 Services within Lyon Cardiovascular Hospital)

So it was not multi country, it was only multi-clinics but all within the same country.

Many paper cited by Katz have methodological shortcoming, he was also muddying the water by speaking interchangeably of vegan diet and then predominantly plant-based diet, so in and all, again, I think the premise of the debate was flawed because I do think the evidence right now in favour of exclusively plant-based diet are rather weak (or at the very least, hard to demonstrate with high quality evidences). But this is also true for animal-based diet. It's easy to say there is no evidence for something. It's much harder to build a case for a position using evidences. So Nina had the easy position of the debate. Would she have had to prove that low-carb, ketogenic diet are healthier, this would not have been so easy. The evidences are quite consistent about plant-predominant (but not exclusive) diet being healthy. Is it healthier than whole-food, animal-based one? We don’t know right now, but I think there is certainly a case to be made to recommend to the population a mediterranean-type diet and expect their rate of chronic diseases to go down.

[u/greyuniwave]

This guy is going thought studies cited by Katz and it seems like katz misrepresented al the ones checked thus far.

https://twitter.com/AmirWeiss1/status/1135611872789639168

https://twitter.com/AmirWeiss1/status/1135402783191048194

[u/beowulf9]

She should have won the debate, but she didn't...

Let's look at the proposition "There is little or no rigorous evidence that vegetarian / vegan diets are healthier than diet that include meat, eggs and dairy."

Essentially it comes down to "what constitutes 'rigorous evidence'? Most nutrition recommendations have been based on epidemiological studies, which have a whole lot of weaknesses - causality, people's memories, virtue signalling, etc.

It is hard to imagine that anybody would claim that epidemiological studies would constitute 'rigorous evidence' - they may be strongly suggestive, but that is it. (if you don't believe me, look up the history of hormone replacement therapy for women)

Randomized controlled trials (RCT) come closer to rigorous evidence, but it is still not a gold standard.

The trap Nina unwittingly set for herself (she went first) is that she didn't make clear that a RCT, while likely more definitive than an epidemiological study, doesn't per se constitute 'rigorous evidence' Each RCT is subject to limitations of the survey design, sample size and confirmation bias of the researcher.

Now if you did a (thoughtful) meta analysis of a large number of RCTs, and it came out showing a clear conclusion on one side or another, you could begin to make a case for 'rigorous evidence'.

By making the threshhold rct vs observational epidemiology, Teicholz opened the door for Katz to flip through 15 powerpoint slides of RCTs that supposedly made his case. Now I am told that many or all of these studies were less than 100% flawless and far less than 100% meaningful, but by not initially setting the bar at thoughtful meta analysis of multiple RCTs, she allowed him to bury her in slides, irrespective of the content thereof ... it was the debate equivalent of a SLAPP suit.... She tried to come back with the fact that meta analyses of these studies showed no such thing, but the damage was done - she had set the bar too low.

And then they both started going off on tangents that had nothing to do with whether the evidence was 'rigorous,' and it declined from there. While Katz may well have been disingenuous (a lot), he was also good on his feet - and teicholz opened the door.

Overall a good debate though - sometimes Soho Forum features obviously smart people who couldn't debate themselves out of a paper bag... in this one, both sides did a good job making their case