Intermittent Fasting

hello i'm dr ken landa thanks for watching let's talk about intermittent fasting calorie restricted eating time restricted eating well it obviously has to do with taking food in well food's very important it's important because it provides us energy and nutrients allows the tissues to grow and repair but if you consume too many calories unfortunately if you get too much nutrition you're going to find that you increase the risk of chronic disease now epidemiologic studies suggest that an excess of intake during middle life that's going to increase the risk of stroke alzheimer's disease parkinson's disease and at least in laboratory animals we know that every other day fasting can decrease all of those conditions now worldwide people are living to a markedly older age but unfortunately that doesn't mean that it's a healthy old age they have a lot of chronic diseases so typically up until relatively recently our attention to diet was look at the composition of the diet look at the calorie intake of the diet but now our attention is the size of the meal the frequency of the meal when it's time during the course of the day how many hours you can eat how many hours you have to fast those are powerful tools to postpone the onset of disease and the aging process now people in our society tend not to stick to diets very well just look around you two-thirds of the population overweight or obese so human trials on calorie restriction and intermittent fasting overall haven't gotten very far there's minimal weight loss marginal improvements in the biomarkers their variable outcomes well the gerontologists the people who study the aging process they say that basically the only thing we have that's an anti-aging paradigm is calorie restriction calorie restriction is going to reduce the metabolism the body will reduce the metabolism going to reduce the amount of oxidants that are being produced and theoretically going to help a lot of tissues now after eating you use glucose during fasting there's not all that much glucose around anymore so you start to use the fatty acids the triglycerides and when you do that there's a metabolic switch and it seems that that metabolic switch opens up the avenues for significant health benefits now the concept in our society at least is you have three square meals a day you have some snacks there's abundance of food there's a lot in marketing marketing for pizzas and hamburgers and chicken wings and a whole bunch of breakfast cereals that are laden with calories and when people start these calorie-restricted diets or time-restricted diets or intermittent fasting then they feel hungry and they're irritable and they have a decreased ability to concentrate if they were to stay on the diets for some period of time for several weeks or months then those symptoms would seem to disappear well the benefits of fasting it seems that we alter the stress response and by ordering the stress response and turning that switch on and then starting to use some of the fatty acids use some of the ketones that seems to be extraordinarily important now in laboratory studies going back 100 years it's been consistently shown at least in the laboratory that calorie restriction is going to improve the lifespan of unicellular yeasts and nematodes and fruit flies and mice and primates now up until recently the concept was just let's see if we can increase the lifespan not the healthy lifespan just increase the lifespan by cutting down the calories and indeed it was found that if you cut back on the calories at least in the laboratory you could increase the overall lifespan by about eighty percent without in a day feedings alternately feelings that begin during early adulthood well analysis from more than 70 years of studies show that about a 40 reduction in calories well that leads to an increase in the life expectancy of rats by about 14 to 45 percent increase the life span of mice 4 to 47 4 to 27 so basically there is some difference in the different animal models and that's important to realize especially if we're going to try to extrapolate to what happens in humans especially what happens in humans before we do the adequate testing well if we manipulate the calories if we manipulate the timing of the meals it seems that we can significantly decrease the health risks to an individual unfortunately there seems to be significant inter-individual genetic variation so not everyone is going to have the same kind of benefit just like when we talked about the rats and the mice there was significant variation in the extension of life expectancy so if we look over the course of a lifetime if we use a calorie restricted diet we're going to find that these changes the benefits that occur vary somewhat according to the sex according to the makeup of the diet according to some genetic factors if we use a calorie restricted diet we decrease the daily caloric intake anywhere between 15 and 40 percent still consuming the standard american diet 30 fat 15 protein and 55 percent carbohydrates but yet we restrict the timing so that there's at least 15 hours of fasting well then it seems that we can get significant benefit now some people have tried as little as a four-hour window up to a 12-hour window those don't seem to provide anywhere near the same benefit so with intermittent fasting what we do is we can go on a complete fast or we can consume during the course of the day fewer than 25 of the normal calories we can do that one or several days during the course of the week and then on the days when you're not fasting then you can consume basically the kind of foods that you would like now a lot of people do this on alternate days or some people do it five days regular diet two days fasting either fasting or as i mentioned calorie reduction so that's basically more popular than continuous or restricted feeding so people don't like to cut down their calories every single day that seems to be a lot tougher than just periodically a couple days a week cutting back on the calories and we also know that we can have fasting mimicking diets we have the keto diet that alters the type of the calories that we consume and then can potentially lead to some benefit so if we look at decreasing the calories to about 30 percent of the energy needs for five days during the course of the week then eating basically normal food for the rest of the month we do that three or four times a year if we have altered the composition of the diet and now consume 50 fat and about 10 protein and about 40 carbohydrate and then back to normal for the off time and consume the food no more than during a 12 hour time period it seems that we can still get significant benefit now if we follow at least in the laboratory calorie restriction of any sort and all of these seem to provide basically the same kind of benefit well those calorie restrictions seem to provide several types of protection against the consequences of the typical western diet so the animals lose weight they increase their energy expense they improve the glucose response they decrease the insulin level they have less hypertriglyceridemia less hypercholesterolemia there is less inflammation the fat mass is less they maintain the free the fat free mass they seem to lose both visceral and subcutaneous fat they have better cardio metabolic health they have a decrease in the blood pressure and it seems that even though it protects normal cells it doesn't protect cancer cells so now we get back to time restricted feeding so if we cut back on the number of hours that food is consumed relative to the circadian clock it seems that we can get significant benefit now the question is how much calorie how much time restriction do we have to have well in studies as i mentioned 4 to 12 hours doesn't seem to cut it even 13 hours doesn't cut it now at 13 hours of fasting during the course of the day yes you can lose some weight and yes interestingly in women who have breast cancer might decrease the recurrence at least compared to a less than 13 hour fast but if we cut back on the total number of hours and we restrict it so that for say 15 to 18 hours we don't consume any food that seems to provide significant benefit especially if we use one of those say five days regular and two days calorie restricted diet well a lot of people have trouble getting into that but if you're considering starting a diet then what you do is you just gradually ease into it so you don't cut back 40 of the calories you cut back a little bit you do that for the first week do a little bit more for the second week finally get down to the total calorie reduction for the third week now in laboratory the goal is to maintain a variety of circulating hormones at relatively normal levels so the insulin like growth factor and insulin itself insulin-like binding protein then we find that the ketone levels are in relatively good shape and all of that is just simply by cutting back the timing of the meals now with intermittent fasting we extend the life span we protect against obesity and cardiovascular disease and hypertension and diabetes and neurodegeneration we slow the growth of tumors and we actually sensitize the cancer cells to the cancer treatment well additionally the blood pressure seems to go down the resting heart rate is slower the cholesterol and the bad cholesterol go down the triglycerides go down the glucose and insulin goes down the likelihood of suffering from insulin resistance goes down and then if we look at the markers of inflammation or oxidative stress they go down too and then if we look in the animal model again feeding every other day it seems that the animals have an improved running endurance and in addition to that they have improved balance and coordination so at least in animal models it seems that calorie reduction calorie restriction can protect the heart the liver and the kidneys from ischemic injuries and cognitive effects seem to be significantly better so if we look at spatial memory or associative memory or working memory all improve by just simply cutting back on the number of calories and restricting the number of hours when the calories are consumed now additionally another benefit is that if we use these calorie restricted diets you can decrease the incidence of tumors that develop over the course of time not only that but you can suppress the growth of the tumors should they develop well with your eyes it's estimated that maybe eighty percent of all significant eye disease is age related you have age-related macular degeneration and cataracts and glaucoma and dry eye and diabetic retinopathy and retinal vascular occlusion and suggestions exist to say that you can control these you can slow them down even if you can't prevent them and as far as hearing is concerned well we know senior citizens have a significant incidence of hearing problems reduce the incidence simply by caloric restriction now we do have some studies for instance in the seventh day of venice they have a couple studies and it showed that on their routine fasting they have 35 percent less coronary artery disease 44 less type 2 diabetes that's compared to normal eating they have lower cholesterol lower triglycerides lower blood pressure they have improved hormone status markers of inflammation are considerably down they have less atherosclerosis less chronic kidney disease less heart disease and diabetes less respiratory disease lower incidence of alzheimer's and parkinson's and huntington and stroke seem to have better memory well how does all of this work you don't really know but there's an increase in what's known as non-shivering thermogenesis that means that you burn fat calories and that seems to increase the amount of energy expense and we can actually measure that by finding that the animals release an increased amount of heat and that's with every other day fasting well additionally we find that if you have asthma the incidence of asthma seems to be reduced if you have cancer well there seems to be some decreased signaling through a variety of chemicals in the body the insulin and growth hormone receptors and a series of other chemicals that seem to reduce the likelihood that cancer is going to grow and spread well all of this feeds into circadian rhythms and it seems that if you restrict the dietary intake and some people would say if you restrict the dietary intake to mostly the morning hours you can significantly improve the body clock and you hear so much talk about circuit well sirtuin is one of those chemicals that seems to benefit by calorie restriction and it benefits by calorie restriction through a whole series of chemical reactions that occur simply because the calories are restricted now if we look at calorie restriction we find that you're going to increase the production of ketone bodies those are chemicals like beta-hydroxybutyrate and acetoacetate and they're used for fuel during fasting but they're also much more than a fuel they seem to be signaling molecules they have effect on the different cells in the different organs they regulate the activity of a whole bunch of proteins and different molecules that we know influence the aging process and it seems that that change to the ketone bodies seems to be extraordinarily beneficial because those ketone bodies additionally seem to have some benefit as far as epigenetic control that turns the genes on and off so gene expression and dna repair and gene stability and neurogenesis so there's more what's known as bdnf brain derived neurotropic factor and it seems that's very important to maintain a healthy brain well additionally we find that the ketone bodies are very important again in regulating the sirtuins that we talked about but fibroblast growth factor 21 a variety of other chemicals like nad whole series of chemicals in the body simply by using those ketone bodies and the brain-derived neurotrophic factor that i mentioned well that has implications for brain health and neurologic disorders and psychiatric conditions well when we look overall we find that if you look during fasting there's going to be significant protection against the oxidative process against metabolic stress against the damaging effects on the different kinds of cells in your body that's not going to happen if you are consuming sugar if you're eating if you're eating standard american kind of a diet now additionally it seems that those ketone bodies have something to do with a switch in what's known as the white adipose tissue white adipose tissue is the typical fat that's accumulating in your belly or on your thighs or inside your abdomen and seemingly some of those cells the white adipose tissue is going to undergo some change it's going to undergo what we call beijing beijing so it sort of turns a lightish brown color and when it turns a lightish brown color then it has more mitochondria and it starts to burn more calories and it's thought that one of the ways that some people seem to eat an awful lot of food and maintain a relatively slim figure it's thought because of their having more beige adipose tissue beige adipose tissue leads to this non-shivering thermogenesis so you're not shaking but you're actually consuming you're using your body is using your body's consuming more of the calories and that's extraordinarily important now it seems that the beige adipose tissue that's increased by the ketone bodies will if we get rid of all of the microbiota the gut microbiome the bacteria in the intestine and we study germ-free animals it seems that none of this dietary restriction is going to work nearly as well or even potentially at all so it seems that those bacteria might be extraordinarily important and remember the ketone bodies are made in two different places they're made principally in the liver and principally in the intestinal lining cells the epithelial cells so now we have another concept and the other concept is the mitochondrial free radical theory of aging so it seems that the mitochondria those cells have a lot of potential to increase the caloric expense and if they do that that seems to be another way of improving the calorie restriction type of benefit now it's important to realize that some chemicals are bad so for instance there's one called nfkb nuclear factor kappa beta and this is responsible for transcription of a lot of pro-inflammatory proteins proteins like alpha tnf and a series of cytokines il1 il2 il-6 and chemokines and adhesion molecules all of which can potentially get you in trouble and it seems that calorie restriction reduces all of that so when we get down to the bottom line it seems that every other day fasting well it increases the beiging of white adipose tissue it reshapes the microbiota it changes the type of bacteria changes the different bacterial components of the intestine and that can reverse some of the effect of a high fat diet induced obesity a series of metabolic disorders so unfortunately not all studies show benefit so for instance at the university of wisconsin they showed that yes indeed caloric restriction was very helpful at the nih the national institutes of aging they didn't show such clear benefit and the reason for that was all sorts of variations in the experimental model and you have to realize that calorie restriction on some strains of mouse well that can have an adverse effect so shorten the lifespan and additionally in humans well there's the potential for anorexia and a series of other eating disorders if people pay too much attention to the intermittent fasting of the calorie reduction human studies so far been very short term most of them and people in middle age or people who were young we know that there are some chemicals that people are investigating that might cause some of the same chemical changes as we find in calorie restriction but i wouldn't believe them because we don't understand really what the basic underlying change is so people are studying metformin people are studying rapamycin and spermidine and resveratrol all suggesting that they might cause benefit lipoic acid the omega-3s well we have a couple different studies we have one called calorie that's the comprehensive assessment of long-term effects of reducing the intake of energy we have the studies on the centenarians in okinawa people who live to 100 years of age and we have something known as the calorie restriction society they call themselves the cronies and they all find basically the same benefit they find the physiologic benefit the metabolic benefit the molecular benefit same kind of thing that we find in the laboratory now if an animal was going to be fed strictly a fatty diet a ketogenic diet basically all the calories coming from fat well we can improve the mouth's health span but we don't improve the mouse longevity we can delay some of the neurologic diseases that might be associated with the aging process so right now intermittent fasting calorie restriction reason people don't do it is because they think it's going to lead to hunger they don't have the satisfaction with the fullness but if we consume a calorie restricted diet a time restricted diet if people follow an intermittent fasting diet then they're not going to have a sensation of hunger so if you miss your meal you get hungry during the course of the day people who are on intermittent fasting tend not to now you also have to be a little bit careful with intermittent fasting and calorie restriction on the potential change in your metabolism so if you happen to be taking a drug that has a relatively narrow therapeutic index do have to be careful and if you stay on a fast for too long a time period like 72 hours to 120 hours actually you increase the amount of fat inside the liver and that can lead to a condition known as non-alcoholic steatohepatitis when we look at people who follow these diets we actually find that they eat less than prescribed on the days when they're supposed to eat an ad lib diet eat as much as they want and we find that they don't cut back enough during the days when they're supposed to be on a calorie restricted diet and surprisingly at least in animal studies some amount of fat is necessary in order to benefit from the whole process and then there are questions does a calorie-restricted diet lead to an increased incidence of bone thinning or osteoporosis what happens to the reserve capacity so that if you have an infection or injury or surgery is that going to cause problems well that basically is the story of intermittent fasting and calorie restricted diets and time restricted diets and alternate day fasting very promising work but most of the work's been in animals some human studies but remember we can't translate the animal studies directly to the human studies how does it work we just really don't know at the present time some people think it's the ketones or sirtuin or oxidant antioxidant level some people think it relies on the circadian clock the time during which you consume the meal whether it's the morning whether it's the afternoon some people think it's the ketone bodies that as i mentioned seem to throw a metabolic switch and cause some changes inside the body and then additionally are interactive with the bacteria that are in the gut some people think it's the fat cells and the fat cells start to beige and they increase the number of calories that they burn and even though it's relatively small number of fat cells they do consume a whopping number of calories so we stand sort of at the precipice of a potentially very important concept in health and nutrition anyway thanks for watching if you enjoyed the show please tell a friend consider subscribing so you'll be notified as we post new videos i appreciate your interest i'm dr ken landown [Music] [Music] so [Music] you

Channel: wellnowdoctor

Views: 4,104

Rating: 4.9670782 out of 5

Keywords: intermittent fasting, calorie restriction, complete fasting, alternate day fasting, keto diet, ketone bodies, healthy aging, increased survival, gut microbiome

Id: wzAhyf_jyG4

Length: 28min 38sec (1718 seconds)

Published: Mon Nov 16 2020