Nutrition and Prostate Cancer What We Think We Know and What We Actually Know

[Music] so I guess this is the the old um Sesame Street which one of these is not like the other kind of talk um I think this is an important topic and we weren't working uh with Dr Stone's talk we weren't sure where up put this in so this seemed like a place in terms of us focusing more on earlier stage kind of PR cancer and something that's that's relevant for all prostate cancer patients so I want to go through you know nutrition and prostate cancer and I think there's a lot of misperceptions I think a lot of patients will come in the door and I say you know what are you doing to eat right they're like I've given up red meat I'm doing everything right and you know and and I'm not sure that's even the right answer but I think a lot of patients want to do the right thing I just don't think often the advice that we give them is the right advice so I want to go through a little bit of kind of what we think we know and then what the data actually show in terms of what we do know so we're going to Define nutrition type of a food of amount of food and we're going to play this game of what we think we know we actually know for all of these we'll Define the nature of the problem we'll talk about excess amount of food macronutrients vegetables and we'll kind of summarize so nutrition is literally and I think this is not from Wikipedia but from other some other enlightened source I'm sure the sum of the processes by which an animal or plant takes in and utilizes food substances so if we do this right um we need macronutrient balance we need to avoid harmful substance we want to minimize calories and maximize how many calories we spend which is physical activity so that is the goal and how we achieve it is highly debatable so this is one of my favorite things they tell patients is the word diet literally means way of life it is not a short-term intervention to look good for the summer in your bathing suit or your high school reunion or or some wedding it really is a way of life and if we do this right we will not only hopefully reduce prostate cancer or all cancer risk aggressiveness severity we're actually going to reduce heart disease and if men diagnosed with prostate cancer more of them actually die of heart disease and die of prostate cancer so if a man's diagnosed with prostate cancer you could say the biggest threat to his life is his heart not his prostate so we need to keep that in mind when we treat patients and the diagnosis of cancer is a wakeup call these men are highly motivated we're actually been doing dietary trials and I'm working with dietitians and they will tell you the cancer patients they are working with are the most motivated patients they have and across all the studies they work on cancer is a very scary time for these men and I don't think we capitalize on that teachable moment I remember reading a study once that 25% of patients stop smoking simply because the doctor said off hand you should probably stop smoking one out four actually did it now 75% don't and there's a problem there but a simple comment here or there can actually mean a lot particularly for newly diagnosed cancer patient when they're striving for this information so at the end of the day calories in minus calories out do eat equal net body weight change so in terms of obesity and prostate cancer what we think we know is that obese men are sicker they're more likely to have heart disease diabetes kidney problems and therefore because they're sicker we don't really have to worry about prostate cancer and even even if we were to think about prostate cancer there's really no reason to link the two what we actually know is that obese men are about 30% more likely to die not get the disease but die from prostate cancer so these are two different studies here one from the 1960s and the one from the ' 80s and '90s and so you heard um from Dr Stone in terms of PSA levels being lower and obese men that's absolutely true back in the 1960s we weren't using PSA to diagnosed tumors we weren't doing radical prostatectomies and the results are the same being obese puts a man at greater risk of dying of prostate cancer how about the amount of food so what we think about in terms of again obesity and and these things is prostate cancer is an older man's disease and every textbook every medical student who reads and goes through is taught there are three risk factors for prostate cancer it's age family history and race every textbook every article starts out those are the three classic risk factors and so therefore the thought is there's nothing we could do well it's not necessarily true so this is a study where basically we went to data from about 880,000 men from the American Cancer Society followed for about 10 years and then from 1992 onwards we saw who got prostate cancer and how bad the cancer was and if you looked at men who lost weight the risk of all cancers was slightly lower than the other group one being no change here to patients who are relatively weight stable but particularly if you looked at the localized high grade can that early stage bad cancers those are the ones that we really want to capture because we think we can make a difference those are going to be the metastatic and fatal cancers in this study they actually reduced by over 40% by weight loss I don't know if it's necessarily 40 it's not a randomized trial these were just people who happened to lose weight but even the metastatic fatal was reduced by about 20% suggesting maybe maybe by losing weight we can reduce our risk of bad prostate cancer how about macronutrients so what we think about dietary fat and I can't tell you how many times I have heard this is high fat diets cause prostate cancer and so cutting down fat will lower our prostate cancer risk now mind you this was the exact same information our government gave us back in the 1980s they said high fat diets cause obesity you need to cut down your fat and what did we as a country do we listened we actually listened the amount of fat in the diet today is less than it was 30 years ago dramatically less what's happened to obesity rates in 30 years so is the government always right is age-old wisdom always right so there are some early data to suggest dietary fat may be linked with prostate cancer but a lot of them didn't really adjust for how obese the man was how much food he ate or many other factors so if we look at newer data and here I picked out one study 140,000 Men followed for eight years absolutely no association between overall fat and prostate cancer risk another study from the United States 880,000 men no association with dietary fat and prostate cancer risk and a review published before for those papers said studies are inconclusive in the role of fat with prostate cancer risk well okay maybe not all fat is bad but you know that there's good fats and bad fats right we all know that I mean fish has fish oil omega-3 and fish is good so fish oil must be good and saturated fat and and beef and all that stuff must be bad I mean okay so it's not so simple fat is bad but you know clearly we know this right right same 140,000 they looked at those no association with any type of fat 880,000 no association with any type of fat in the study they actually looked at meat and fat and saw nothing so now the thing is this is where it gets actually to me kind of fun but gets a little complex so there are some data about the Omega-3s what we call quote unquote fish oil though we'll see in a minute not all fish have the same amount of fish oil and actually grass-fed beef actually has a fair amount of mea3 nuts have it other sources has been shown in some studies to reduce heart disease and there is some data to suggest it reduces prostate cancer risk there's actually some data that blood levels if they are high may increase prostate cancer risk so even that's not a slam dunk that omega-3 equals good but importantly this not all fish are alike and what we think notice I say think because we don't know what we think is important is the ratio of omega-6 which is your corn oil your your fat bad fats quote unquote to your Omega-3s which are your quote unquote good fats so Omega 6 is pro-inflammatory it's a radonic acid breaks down in metabolites and the ratio we think is important we think humans evolved ating about a one: one ratio maybe a 2:1 ratio if we look at Japan the Asian diet where prostate cancer rates are much lower than they are in the US it's about 4 to one in Western countries it's as high as 10 sometimes maybe even 20 to one it's a lot more omega-6 but the interesting thing here is we look at how much bad fats Omega 6 is in different foods tilapia has 134 gram look at that it has 30 times the amount of a doughnut four times as much as a hamburger and if you look at the ratio here Farm sloppy is 11:1 that's a western diet farm catfish 4:1 farm salmon and we know Wild's going to be better I've never seen wild tilapia you do get get wild salmon less than one: one so salmon being pretty good catfish so so tilapia is not and actually the followup what they read if you read the text of this to me this was fascinating if you read the text for individuals who are eating fish as a method to control inflammatory diseases such as heart disease is clear from these numbers that tilapia is not a good choice all other nutritional content aside so again forgetting the other nutritional content sugar and everything else the inflammatory potential of hamburgers and pork bacon is lower than the average serving of tilapia tilapia should be your dessert that's your sweet the bad thing that you eat at the end of the meal because you feel you need something a little bit more that's what tilapia should be so when patients come in and say I've given up eating red meat I'm eating nothing but fish I'm doing right doctor well what kind of fish oh I'm eating tilapia because that's what I like and it tastes great and it's cheap uh-uh they're actually harming themselves we think how about grain fed beef Omega 6 versus omega3 here your standard stake you buy in the store is 4 to one it's actually not so bad and if you're able to get grass-fed you're down to 2: one remember the Asian diet was 4 to one lower we think is better grass-fed beef is better than the Asian diet so patients giving up red meat this e tilapia thinking really wanting to do the right thing because they've given up red meat and they're eating fish and that's the problem is when we give buzzwords to people people come in I was at a literally last night I was in Los Angeles at a patient support group and a patient asked me I was talking about diet and he asked me is a vegetarian diet good for prostate cancer I said you know it's a loaded question because to me in my mind what I jump to and worry about is Twinkies are a vegetarian diet there is no meat in a Twinkie that is a plantbased vegetarian diet is a Twinkie so if that's what he's eating absolutely no that's not good if he's eating salad and he's eating fruit and kale and he's eating broccoli then it probably is good so again we need to get rid of these simple concepts of given up red meat I'm eating fish I'm doing right and really spend the time with the patients understanding what they're actually doing so in terms of fat are there animal data that cutting out fat is good and the answer at least in animal data is yes and this is a study they used Corno oil so again Omega 6 we think is on the bad side still I would say a lot of this is controversial but we think if there is a bad fat it's going to be Omega 6 and and cutting out going to low fat feeding the same amount of food significantly slowed tumor growth again in a mouse what do we know about humans and the short answer is we don't so there was one study which gets a lot of talk and a lot of press and there was 93 men on watchful waiting for this is historical data published in 2005 so this is not active surveillance this is more of a watchful waiting group PSA is less than 10 glein less than seven so you're you're lowrisk patients randomize to a standard diet which is basically keep doing what you're doing or an intensive lifestyle intervention so 10% dietary fat extreme extreme low fat when we talk about low fat American Heart Association recommends low fat they recommend 30% American diet's probably about 35 right now you go back to the 70s when actually our waist lines were half of what they are today there's actually probably more like 40% of dietary fat we about 35 34 this was 10% very very low vegan diet they also had yoga they had meditation they actually took supplements um vitamin E back in the day we thought that was good look it's a natural vitamin must be good so we ran the trial and found an increased prostate cancer risk so they were throwing a lot of things at these patients and they did show a slight decrease in the PSA levels in the experimental group and a slight increase in the Standard Group not a Smoking Gun but that is some of the best data we have so the problem is what you do is to avoid fat as people go eat lowfat Foods so I remember my daughter coming home from Halloween one year and she had a pack of Skittles she had gotten for Halloween and big lettering on the front pack of the Skittles said a fat free food must be good for you it's fat free right what could go wrong with Skittles I mean so the problem is people went and bought fat lowfat ice cream you bought lowfat desserts and so sugar intake went through the roof and what we've done is we've increased obesity rates so what do we know about sugar and prostate cancer well the traditional thinking is Sugar's just a filler your body's going to burn it and most of the research historically is focused on fats and proteins and we didn't pay a whole lot of attention to Sugar so but what we actually know is that particularly refined carbohydrates simple sugars lead to insulin spikes and if you take prostate cancer cells in a Petri dish and you throw on insulin the cells grow faster that's pretty clearcut at least in a Petri dish we see this in animals as well when you give them insulin the excess carbs we know lead to obesity there was a very nice study that sh looked at 827 men who had prostate cancer all physicians may be relevant to people in the room here and that they showed that the C peptide levels which is a measure of insulin levels the higher it was the more likely those men were to die of their cancer so what happens if we cut down on sugar so this is a study by some colleagues of ours where they cut out sugar in the diet and the tumors grew slower in mice the challenge is by cutting out sugar they actually cut out a lot of the food so these mice were actually skinnier so we did a very similar study here where we didn't make the mice skinnier we fed in the same amount of food we just changed the type of food that they ate and this is in terms of survival of the mouse you can see if you're on a western diet well that's bad bad low fat was better and this was about a 12% vegan esque amount of fat and if you want to constrict in this case we want extreme low carb to the point of no carbohydrates something you can do in a mouse is a lot more challenging to do in a human but you can get down to a couple percent carbohydrates very difficult but doable and significantly prolonged survival so again that's in the mouse what do we know in a human we don't know so we are actually conducting right now Phase 2 randomized trial of Ain which is a low carb we're focusing on induction phase acin for 6 months 20 grams of total carbohydrates per day carbohydrates are 4 calories per gram that's 80 calories assuming you're eating probably eating about 1,500 calories so we're talking about 5% of carbohydrates calories 95% are fat and protein and men with a rising PSA to see if we can slow the rate of PSA doubling time and men with recurrent disease after surgery or radiation about 40 patients into the study so how about micronutrients what we think about tomatoes well tomatoes are good right I mean lopine and it's a healthy food that that reduces prostate cancer risk right so this is the official FDA stance on it is the evidence found no credible evidence no credible evidence to support an association between lycopene and reduced risk of prostate and very limited to support an association between tomato consumption and reduced risk of prostate cancer and one interesting study to me it was interesting is that found that tomato paste actually slowed prostate cancer growth but lopine did not so I think to me as I think about it as we try and get reductionist and what is the one phytochemical the one molecule in something as complex as an entire fruit or vegetable depending on how we Define tomato heard both arguments that you're not going to get the answer you got to eat the whole food and something actually very interesting about tomatoes as well is assuming it is lopine that we think is beneficial is lopine is fat soluble meaning if you eat a tomato like you would an apple just in the middle of the day you actually aren't going to absorb any of the lopine now if you add some Buffalo mozzarella cheese and you add your olive oil and you make a very nice capry salad then you're going to absorb the lycopene it's actually the best data on tomatoes that are out there are not Tomatoes but tomato sauce now yes tomato sauce often has sugar in it which I don't think is a good thing but where do you eat tomato sauce you eat it on Pizza greasy Pizza you eat it with your meatballs and your pasta you're having it with fat and you actually get absorb the nutrients so again it's not just thinking about the food vitamin D is another fat soluble uh molecule so when you have your skim milk fortified with vitamin D you don't actually absorb any of it so if you have Pati who are trying to get their vitamin D levels up and they're eating a strict vegan diet it's not going to happen they're not going to absorb the vitamin D so again things that we start to think about reductions I'm just going to take a pill and that's going solve all my problems there are no shortcuts so in summary if we do this right if we can do this right that we will have something that can reduce cancer risk cancer severity reduce the side effects allow PSAs to be more accurate we we go down the list of different things that could be done the problem is we don't know and the minute we think we know we're actually probably wrong and that's where we need to start at the beginning and say we don't know there's some things that seem to be perhaps accurate there's so much more we need to know so how do we function in this world of uncertainty what are some take-home messages so this is what I try and a live for myself some days better than others but what I certainly what I try and tell my patients which is you want to go low on calories and low on the carbohydrates particularly simple carbohydrates we can have a nice debate about complex carbs whether they're good for you or just less bad for you um I'll leave it at that not necessarily go where I think but nonetheless simple sugars clearly I think are part of the enemy we want to go high on the exercise there's a lot of data now I don't know a lot there are certainly several papers now linking vigorous exercise with reduced prostate cancer risk and mortality not just gent and out for a leisurely stroll in the evening but tell patients if you can have a con nice conversation while you're exercising you're probably not doing it hard enough you need to get your heart rate up you need to get your breathing going and for whatever for you is vigorous that's how you Define vigorous is you can't talk through it you do want to eat fruits and vegetables the DAT are actually pretty poor to support fruits and vegetables as anti-cancer um I think they are beneficial when they replace something else so instead of having the potato if you have a salad instead great if you're going to have the potato and dessert and just adding a salad probably not doing yourself a lot of benefits nuts I think again are a good little snack particularly a lot of patients do well during meals but fall down at snack time they get hungry they eat the potato chips they eat the candy bar so nuts are a good snack good healthy fats again we think healthy legumes which is your beans your peanuts I think meat is okay we evolved as a species eating meat but we evolved eating animals who ate their natural diets so if you are going to eat meat you want to keep them from animals eating their own Natural Things grass-fed beef wild fish free range chicken that type of thing probably the most important thing was to achieve and maintain a normal body weight we heard about obesity on many levels here today the adverse effects really is quite significant and that is pretty uncontroversial in terms of its linked with aggressive prostate cancer and again I I think there is value in the adage that heart healthy is prostate healthy and if I can leave with one adage is that genes load the gun but lifestyle pulls the trigger thank you for your [Music] attention

Channel: Grand Rounds in Urology

Views: 75,034

Keywords: Stephen J. Freedland, Scottsdale Prostate Cancer Symposium, SPCS, Grand Rounds in Urology

Id: ayjYnZy5OVM

Length: 25min 24sec (1524 seconds)

Published: Thu Jun 01 2017