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TEDx Talks
Published: 2014-03-18
Source: https://www.youtube.com/watch?v=4UkZAwKoCP8
thanks Brian and I'm at the National Institute on aging and as many of you know as a people are getting older and there have been advances in cancer research cardiovascular disease research are many people who would have died %HESITATION in their fifties and sixties from those diseases are living into the danger zone for Alzheimer's and Parkinson's disease it's projected that by twenty fifty the number people
with Alzheimer's disease %HESITATION will triple from what it is today it's five million today B. fifteen million by twenty fifty in my lab we use the number different animal models that are relevant to age related nobody general disorders we have mice that accumulate amyloid in their brain as they get older and they have learning and memory problems we have mice that have damage to dopamine producing
Iran's the control body movements that's the mark of a mile of Parkinson's disease and we also have miles of stroke which is it again another major a problem and and cause of death well it's been known for a long time that one way to extend the lifespan of laboratory animals is simply to reduce their energy intake and in rats and mice one can increase their lifespan
by thirty or forty percent we started looking at the effects of energy restriction on the brain in the context of age related nobody jam disorders and found that we could slow down the for example abnormal accumulation of amyloid or the degeneration of dopamine neurons in the Alzheimer's and Parkinson's mild by reducing energy intake now there's a number of ways you can reduce energy intake you can
simply eat less at each meal or you can do what we call intermittent fasting so reduce the frequency of the meals and what I'm gonna tell you today is that %HESITATION fasting does good things for the brain %HESITATION in the animals we have inside an exact into a lot of the neural chemical changes that are occurring in the brain that we think explain why about fasting
is good for the brain but I'm gonna start out and talk a little bit about anecdotal evidence that fasting is good for the brain and also as a evolutionary perspective on why fasting might be good for the brain okay so everybody knows that %HESITATION certain religions people will fast periodically %HESITATION down through history %HESITATION many famous %HESITATION brains people with famous people with good brains %HESITATION
have fasted regularly up in the top here is a quote from Plato he fast for greater physical and mental efficiency %HESITATION there's some quotes there %HESITATION including one from %HESITATION six about six thousand years ago from the Egyptian pyramid inscription that says humans live on what quarter a quarter quarter of what the on the other three quarters live their doctor and in this country as you
know %HESITATION being overweight is a big problem it's not only a risk factor for cardiovascular disease and %HESITATION diabetes certain cancers but the merging evidence suggests that it's also a risk factor for age related cognitive impairment and possibly Alzheimer's disease and the lower right there is a reference to a book written %HESITATION over a hundred years ago by Upton Sinclair many of you may know Upton
Sinclair's the author of the jungle a a book on the meat packing industry but he also wrote and published a book that you can find the full text online it's called the fasting here and it's in that book he interviews two hundred fifty people who had some ailment and went on the fast for various lengths of time and except in a handful of cases they're %HESITATION
health condition improved okay up before you focus on the brain what will be the main part my talk I just want to point out that there's evidence not just from animals but but from humans that fasting is good for the body it will reduce inflammation it will reduce oxidative stress in organ systems throughout the body and one thing that happens when you fast that does not
happen when you eat three meals a day is that your energy metabolism shifts so that you start burning fat every time you eat a meal the energy goes in your liver and it's stored in the form of glycogen whips and so %HESITATION if you can get the sled that it's stored in the form of glycogen and that's always tapped into first and it takes about ten
to twelve hours before you deplete the glycogen stores in your liver okay so if you eat three meals a day you never deplete the glycogen stores near liver although if you exercise you can %HESITATION and %HESITATION but once you deplete the glycogen stores a new liver then you start burning fats and you produce what are called ketone bodies now it turns out a he toned bodies
are very good for your brain and I'll talk about that in a minute now we've done a lot of work on animals %HESITATION in the nineties and %HESITATION between fifteen and twenty years ago showing that intermittent fasting was good for the brain that we start collaborating with some investigators that some human studies looking at the facts on the body some that were shown in the last
slide and then %HESITATION a the producer at the BBC named Michael mostly made a program on intermittent hassling that was aired on the BBC it's been aired on PBS he wrote a book called the fast diet and just in the last two years there's been a flurry of books on intermittent fasting for health and there's becoming what %HESITATION I think with some people made so I
think it's a fad but hopefully it will people are can find some of these up so what I mean by intermittent fasting amendment energy restriction there's a lot of variations there being unused on this one sort of harsh one is every other day only eat five hundred calories in our human studies we've done doing what's called the five two diet where two days a week you
only need five hundred calories the other five days you eat normally it healthy if you can %HESITATION this book called the eight hour diet %HESITATION there's evidence that if you restrict did time window that you eat each day two eight hours or less %HESITATION it will have health benefits again again that's long enough to shift the energy metabolism okay why does fasting both your brain power
during development your brain but also in your dull in the adult neurons are generated from stem cells they grow out their axons and dendrites they form connections with each other synapses and communicate with it with each other during ageing %HESITATION many people their brain ages successfully they stay cognitively intact whereas unfortunately others develop diseases we think the reason the main take all message of this talk
is that fasting is a challenge to your brain and your brain responds to that challenge of not having food by activating adaptive stress response pathways that help your brain cope with stress and risk resist disease does this make sense in evolutionary terms wanna anything we talk about in biology we have to always ask the question why is it that way why when we take animals and
put them on an intermittent fasting diet other neurons protected in miles of Alzheimer's and Parkinson's disease why do they perform better when we test their learning and memory in mazes well if you're hungry and haven't found food you better figure out how to find food you don't want your brain to shut down if you're hungry and in fact that's what we find in the animals nerve
cells circuits are more active %HESITATION some of the changes in the brain that occur within him and fasting also occur with vigorous exercise now I'm lost people and and Jeff this morning gave a nice talk on showing the benefits of exercise on him I think he probably found it benefited your brain to okay and I'm so we're finding when we start looking at one of the
neural chemical changes in the brain with intermittent fasting they're very similar to exercise now this slide the in the upper left picture the third boy on the right running that's my son is in the audience you can tell by the face of these three kids there in a crowd there in a cross country race that's a challenge right at least they're probably saying to themselves during
the race I I use or run races still occasionally do why am I doing this however however when they get done with the race they feel great and they feel relaxed during the cross country season my wife and I it's very obvious our son's mood was better on their right my daughters in the White her mood was better during the cross country season why is that
exercise and intermittent fasting both increase the production of proteins in the brain that are called neurotrophic factors we discovered this many years ago back when as a postdoc in Colorado in the nineteen eighties we found that these no trophic factors such as FGF in one call beat enough brain derived neurotrophic factor promote the growth of neurons promote that connection of neurons and strengthening and synapses okay
so here's the idea challenges to your brain whether it's intermittent fasting vigorous exercise or what we're doing now hopefully if you haven't fallen asleep is cognitive challenges when this happens neural circuits are activated levels of neurotrophic factors such as beat enough increase that promotes the growth of the neurons the formation and strengthening of synapses also shown in the lower left it turns out both exercise interment
fasting and using your neuron's %HESITATION using your brain can increase the production of new nerve cells from stem cells at least in one region of the brain called the hippocampus which is shown here I mention ketones which come from burning fat and that happens during fasting the Romans discovered ketones even though they had no I they hadn't taken any chemistry courses no it was a people
with epileptic seizures back then they thought they were possessed by demons and they found if they take these people and shot them in a room and don't feed them the demons will go away what's happening is ketones go up and it's well known that ketones suppressed seizures and in fact ketogenic diets are used to treat even today patients %HESITATION with severe epilepsy we're doing in my
work in my lab trying understand why ketones are good for now runs one reason is they provide an alternative fuel the nuns that boosts the energy levels in the near out recently we discovered that fasting by increasing BDNF levels in the brain this neurotrophic factor %HESITATION can increase the number of mitochondria in your nerve cells and I'm not gonna go into the details of the slide
but the mechanism is very similar to the mechanism whereby exercising your muscles increases the number mitochondrion your muscles the fasting is a mild energetic stress and the neurons respond adaptively by increasing mitochondria which helps them produce more energy and then this paper cited down here nature communications we recently showed that up by increasing the number of mitochondrion neuron's it can increase the ability of the neurons
to form and maintain synapses and thereby %HESITATION increase %HESITATION learning and memory ability in addition to the increasing neurotrophic factors and increasing the energy under Ronald bio energetic Jetix if you will we have found that intermittent fasting will enhance the ability of your nerve cells to repair DNA so right now at and and also probably %HESITATION exercise and %HESITATION and also %HESITATION intellectual challenges and again
what's happening in this case when you're using your neuron's exercising your neurons a it causes a mild oxidative stress and at the the same time that there's increased oxidative stress the cells are enhancing their ability to repair oxidative damage to DNA why why is it that the normal diet is three meals a day plus snacks it isn't that it's the healthiest dot ways eating patterns and
that's my opinion but I think there's a lot evidence to support that there are a lot of pressures a to have that eating pattern there's a lot of money involved the food industry are they gonna make money from skipping breakfast like I did today no they're gonna lose money if people eat fast the food industry lose money what about the pharmaceutical industry what if people yeah
do so intermittent fasting and exercise periodically in a very healthy is the pharmaceutical industry gonna make any money on healthy people so one challenge for society and in this one of the purposes of these Ted talks hopefully is that %HESITATION communication is the way to improve health people understanding what they can do to improve their health and then taking action like Jeff talked about %HESITATION in
his own a talk this morning so I would urge you to communicate and spread the word that there are ways for people to be healthy %HESITATION and maybe we can do this even with %HESITATION because I'm working for the NIH and one thing about the NIH is we're using your taxpayer's money to try to help your health we don't have a profit motive and so that
really one of the main reasons I got interested in things like intermittent fasting exercise trying to understand that the southern molecular level what's happening in the brain is this is a research there doesn't commonly done and it's not done it all by pharmaceutical industries in a stock done so much so I'm gonna end with a slide and %HESITATION thank you very much for your attention and
%HESITATION try it out it you can just play around with his a for these kinds of diets and you may find what we found in our human studies though is its kind like exercise if you've never exercise before and you study about run three miles you're not gonna feel good if you eat three meals a day and all of a sudden you go hold they don't
eat anything that they are gonna feel irritable and ornery and so on but it turns out if you can kinda force yourself to do that maybe one day a week for a month and then two days a week you get used to it and after a month or two many people can adapt to that kind of diet with no problem and you'll find on the days
