Why fasting bolsters brain power: Mark Mattson at TEDxJohnsHopkinsUniversity

Translator: Madina Juarez
Reviewer: Carlos Arturo Morales Thanks, Brian. I am at the National Institute on Aging,
and as many of you know– people are getting older,
and there have been advances in cancer research,
cardiovascular disease research– many people who would have died
in their 50s and 60s from those diseases are living into the danger zone
for Alzheimer’s and Parkinson’s diseases. It’s projected that by 2050,
the number of people with Alzheimer’s disease
will triple from what it is today. It’s 5 million today,
it’ll be 15 million by 2050. In my lab, we use a number
of different animal models that are relevant to age-related
neurodegenerative 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 neurons, that control body movements–
that’s Mylo-Parkinson’s disease. And we also have models of stroke,
which is again another major-rate problem and cause of death. Well, it has been known for a long time
that one way to extend And, in rats and mice one can increase
their life span by 30 or 40%. We started looking at the effects
of energy restriction on the brain in the context of age-related
neurodegenerative disorders, and found that we could slow down,
for example, the abnormal accumulation of amyloid,
or the degeneration of dopamine neurons in the Alzheimer’s and Parkinson’s myel
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 am going to tell you today is that fasting does good things
for the brain. In the animals we have insight into
a lot of the neurochemical changes that are occurring in the brain
that we think explain why fasting is good for the brain. But I am going to start out and talk a little bit
about anecdotal evidence that fasting is good for the brain, and also evolutionary prospective on why fasting might be good
for the brain. OK. So everybody knows
that in certain religions people will fast periodically. Down through history many famous people with good brains have fasted regularly. Up on the top here is a quote from Plato, he fasted for greater physical
and mental efficiency. There are some quotes there, including one from about 6,000 years ago, an Egyptian pyramid inscription that says, “Humans live on one-quarter
of what they eat; on the other three-quarters live their doctors.” And in this country, as you know,
being overweight is a big problem. It’s not only a risk factor for
cardiovascular disease and diabetes, certain cancers,
but emerging evidence suggests that it’s also a risk factor
for age-related cognitive impairment, and possibly Alzheimer’s disease. In the lower right,
there is a reference to a book written over a hundred years ago
by Upton Sinclair. Many of you may know Upton Sinclair
is the author of “The Jungle”, a book on meatpacking industry,
but he also wrote and published the book that you can find in the full text online,
it’s called “The Fasting Cure”. In that book he interviewes 250 people
who had some ailment and went on fast
for various lengths of time, and except in a handful of cases, their health condition improved. OK, before I focus on the brain,
which will be the main part of my talk, I just want to point out that there is evidence
not just from animals, 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 fats. Every time you eat a meal
the energy goes into your liver and it’s stored in the form of glycogen– and it’s always tapped into first. And it takes about 10 to 12 hours
before you deplete the glycogen stores in your liver. So, if you eat three meals a day
you never deplete the glycogen stores in your liver, although if you exercise
you can. And once you deplete
the glycogen stores in your liver then you start burning fats, and you produce
what are called ketone bodies. It turns out ketone 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 in the 90s, between 15 and 20 years ago, showing that intermittent fasting was
good for the brain, then we started collaborating
with some investigators, did some human studies
looking at effects on the body, some that were shown on the last slide. And then a producer at the BBC
named Michael Mosley made a program on intermittent fasting
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 it’s becoming what, I think–
some people may think it’s a fad, but hopefully people find some of these– What do I mean by intermittent fasting,
and intermittent energy restriction? There’s a lot of variations,
that there’ve been on used on this. One sort– a harsh one is
every other day only eat 500 calories. And in our human studies we’ve been doing
what’s called the 5:2 diet, where 2 days a week
you only eat 500 calories, the other 5 days you eat normally. Eat healthy if you can. In this book called “The 8-Hour Diet”
there’s evidence that if you restrict the time window that you eat each day
to 8 hours or less, it’ll have health benefits, again, that’s long enough
to shift the energy metabolism. OK, why does fasting bolster brain power? During development of your brain,
but also 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 each other. During aging, many people–
their brain ages successfully, they stay cognitively intact, whereas, unfortunately,
others develop diseases. We think the reason,
the main take-home message of this talk, is 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 resist disease. Does this make sense
in evolutionary terms? Anything we talk about in biology,
we always have to ask the question, “Why is it that way? Why when we take animals and put them
on an intermittent fasting diet, are their neurons protected, in mice,
of Alzheimer’s and Parkinson’s disease? Why do they perform better
when we test their learning and memory?” It amazes. 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 cell circuits are more active. Some of the changes in the brain
that occur with intermittent fasting also occur with vigorous exercise. Now, most people, and Jeff this morning
gave a nice talk on showing the benefits
of exercise on him. I think you probably found
that it benefited your brain too? OK. So, when we start looking at what are the neurochemical changes
in the brain with intermittent fasting. They are very similar to exercise. Now on this slide,
in the upper left picture, the third boy on the right running,
that’s my son, he is in the audience. You can tell by the faces of the 3 kids–
they are in a cross-country race, that’s a challenge, right? They are probably saying
to themselves during the race– I used to run races myself,
I still occasionally do– “Why am I doing this?” 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 the right, my daughter is in the white. Her mood was better during
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 I was a postdoc in Colorado in 1980s. We found that these neurotrophic factors,
such as FGF, and one called BDNF, brain-derived neurotrophic factor,
promote the growth of neurons, promote the connection of neurons,
and the strengthening in synapses. OK, so here is the idea: Challenges to you brain,
whether it’s intermittent fasting, vigorous exercise,
or what we are doing now, hopefully if you haven’t fallen asleep,
is cognitive challenges. When this happens,
neurocircuits are activated, levels of neurotrophic factors
such as BDNF 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 and intermittent fasting,
and using your neurons, using your brain can increase the production
of new nerve cells from stem cells, at least in one region of your brain,
called the hippocampus, which is shown here. I mentioned ketones,
which come from burning fat, and that happens during fasting. The Romans discovered ketones
even though they had no idea, they haven’t taken any chemistry course,
or didn’t know what it was. People with epileptic seizures back then, they thought they were possessed
by demons. And they found if they take these people
and shut 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
ketons suppress seizures, and in fact, ketogenic diets
are used to treat, even today, patients with severe epilepsy. We are doing my work in my lab trying to understand
why ketones are good for neurons. One reason is they provide
an alternative fuel for the neurons, they boost the energy levels
in the neurons. Recently we discovered that fasting, by increasing BDNF levels in the brain,
as a neurotrophic factor, can increase the number of mitochondria in your nerve cells. And I am not going to go
into details of this slide, but the mechanism is very similar
to the mechanism where by exercising your muscles
increases the number of mitochondria in your muscles. The fasting is a mild energetic stress,
and the neurons respond adaptively by increasing mitochondria,
which helps them produce more energy, and in this paper cited down here,
“Nature Communications”, we recently showed that by increasing the number
of mitochondria in neurons, it can increase the ability of the neurons
to form and maintain synapses, and thereby increase
learning and memory ability. In addition to the increasing
neurotrophic factors and increasing neuronal bioenergetics, we’ve found that intermittent fasting will enhance the ability
of your nerve cells to repair DNA, so right now– and also probably exercise, and also intellectual challenges. And again, what’s happening in this case
when you are using your neurons, exercising your neurons, it causes a mild oxidative stress, and at the same time
that there is increased oxidative stress the cells are enhancing their ability
to repair oxidative damage to DNA. Why is it that the normal diet
is three meals a day plus snacks? It isn’t that it’s the healthiest way,
eating pattern, and that’s my opinion, but I think
there’s a lot of evidence to support that. There are a lot of pressures
to have that eating pattern. There’s a lot of money involved. The food industry,
are they going to make money from skipping breakfast like I did today? No, they are going to lose money. If people fast the food industry
loses money. What about the pharmaceutical industries? What if people do
some intermittent fasting, and exercise periodically,
and they are very healthy? Is the pharmaceutical industry
going to make any money on healthy people? So, one challenge for a society, and this is one of the purposes
of these TED Talks, hopefully, is that 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 So, I would urge you to communicate,
and spread the word that there are ways for people
to be healthy, and maybe we can do this even with– Of course, I am working for NIH,
and one thing about NIH is we are using your tax payer’s money
to try to help your health. We don’t have a profit motive. So, really one of the main reasons
I’ve got interested in things like intermittent fasting,
exercise, trying to understand
at the cellular molecular level, what’s happening in the brain. This is research that isn’t commonly done, and it’s not done at all
by pharmaceutical industries, and it’s not done so much. So, I am going to end with this slide. And thank you very much
for your attention. And try it out, you can just play around
with these kinds of diets, and you may find… What we found in our human studies
though is it’s kind of like exercise: if you’ve never exercised before,
and you go and run 3 miles, you are not going to feel good. If you eat 3 meals a day, and all of a sudden
you go all day not eating anything that day you are going to feel irritable,
and ornery, and so on. But it turns out if you can
kind of 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 that on the days
when you don’t eat so much you are more productive.
Thank you. (Applause)

About the author


  1. My whole life I've had a low appetite, eating 1 or 2 meals aday. Trying to eat healthy foods and make the most of those meals of course, and staying well hydrated. People have always looked at me weird or said I ate like a bird or wondered if I had an eating disorder. I've always been pretty healthy, though I would like to lose a few pounds now it entering my mid thirties… I've always been told you need to eat between 3 to 6 meals per day and never skip breakfast. That to be healthy you had to keep eating every 4hrs, adding logs to the fire and keep that metabolism burning. Now it's a medical breakthrough to do intermittent fasting… you never know what the world is going to discover… guess I'll keep on keeping on. Lol

  2. Mmmm…. หมอเองก็อดข้าวมาหลายวันแล้ว ผอมซะ

  3. Brilliant video.
    There’s a great fasting app called Zero
    If you are IF, you should download it.

  4. Fantastic video. It's not good to just do something, but to know the science behind why you are doing something. Thank you for the video 🖤

  5. Cold showers + meditation + yoga + fasting + ketogenic/carnivorous/epigenetic diet + stoic philosophy + nofap = GOD MODE

  6. Excellent recap of fasting benefits.
    – –
    I've been on 17..18h fasting window for a year now.
    Digestion problems, mental fog, constant graving for food = gone.
    Also, hadn't seen sixback since my early 20's.
    – –
    Snacking often might be beneficial to children and teens.

  7. Intermittent fasting is not hard or challenging. Don’t eat a few hours before bed and don’t eat a few hours after you wake up. Even if it’s just 2 hours before bed and 1 hour after you wake up to start. Most will find rather quickly that it’s not as bad as you think and you’ll feel good

  8. But this guy doesn't appear to be very healthy. The way he hisses during pauses suggests that his brain doesn't function well either.

  9. Listen mate!
    You have to eat little bit of everything, no do much of anything: raw eggs in the morning mashed into a glass with maybe a little bit of a salt or baking soda, rest of the day you may have a nice barbeque steak with a nice bowl of salad also…

  10. Muslims fast one month of the year as you all know. Also recommended (not mandatory) to fast Monday’s and Thursdays.

  11. Engaging talk. Intellectual mannerisms of a learned and practising scientist made this talk more endearing. But one thing I feel, Mart Mattson is practising this too much and it takes it in his body.

  12. I am a Muslim living in the Greater Boston Area. I have been fasting for the past three weeks because it is Ramadan. But I have for the past two years fasted each Monday and Thursday because our prophet Muhammed Peace be upon him said it is the way of the prophets before you. All prophets fasted Monday and Thursday including Jesus, Moses, Abraham, and all the other prophets. They fasted the Islamic fast ( remember the world Islam in Arabic means to submit your will to your creator and none have done more so than the prophets). The only prophet who used to fast every other day was prophet Dawud ( AKA King David to the Christians)

    As a testament to what this man is saying, I can assure you that he is 100% right. I feel a huge boost of energy every time I fast during Mondays and Thursdays. I feel like I am lighter , quicker, more alert, and very sharp. The days I don't fast however I feel less energy and a bit sluggish, and drowsy because of all the food I have been eating. The way Muslims fast is very different than the way Christians, Jews and others fast. We eat and drink ZERO foods and liquids form sunrise to sunset. I can assure you that FASTING is the way to go if you want to extract toxins, clean your system, become healthier, lighter, smarter, more alert, and get rid of all diseases.

    By the way in Haddith ( Prophet Muhammed PBUH Sayings ) and Islamic literature, Muslim scholars have said that all pro peace be upon then had an amazing physic including having 6 packs , and a v shaped body, and lean, and svelte appearance, and that they were all very strong men.

  13. What a great idea. If you don’t eat, you won’t poop. If you don’t poop you don’t use the toilet so much, therefore you use less fresh water. Your water bill will be lower. The thing about C. Elagans, is starving them so much that their reproductive organ shuts down, and I’m sure most humans wouldn’t like that.

  14. this's like a natural DNA modification for more intelligence better memory, overall health, and slow aging , hats off to you sir

  15. Food, Medical industries and population control is why the modern diet is what it is. We are waking up. Lot of fear out there now because we are.

  16. Absolutely working for me i m a muslim i am 39 years old and i m fasting since 30 years for the whole month of ramadan for 30 days.
    But this ramadan i start running while i was fasting around 10k then add some exercise then add cycling and i m feeling like 9 years old out of 39 years.
    So many times while running i felt it could be end of my heart at the end it never happened.
    Thanks to almighty Allah and his messenger Prophet Muhammad (peace be upon him ) who taught us this practice.
    If one can put himself into a position where only one heartbeat and one breath is the goal of their life then what you think on that situation that will take you to a point where you feel the power of human brain. May Allah bless all humans that peace of mind and tranquility. (Ameen)

  17. I am a Muslim , I started fasting from the age of 8, at the age of 14 I was fasting for the whole month of Ramadhan, , I am past 70 , and I continue to fast through the whole mont of Ramadhan , always felt great ,

  18. A lot of thanks for you to explaining it so clearly .
    And I am a Muslim Who is blessed by Month of Ramadan.

  19. Got into intermittent fasting by reducing breakfast size over the course of a week. Just a cup of green tea and a glass of water for me. Sometimes I break the habit to share a meal with my little girl.
    Feel much better!!!!!

  20. Peace to All. Aslam Alaikum, Muslims keep fasting 30 days in Ramadan Month, every year. Throughout their lives, Fasting is obligatory..

  21. Today is Saturday. I started Intermittant fasting Thursday ,2 days ago. I fasted thursday and Friday only 2 days so far. I basically skipped breakfast. I workout from 12 pm to 1 pm. Eat at 2 pm tp 8 pm. Starting weight 210. Friday morning 205. Sat morning 208. I havent slept 8 hours in a row in years. The last two nights I slept like a baby 8 hours.

  22. Great talk. I am trying to loose weight and understanding all the biochemistry of what is going on helps me stick to it.

  23. As of this comment I've been doing IM for 19 months and a semi keto diet for about a year. Not only did I lose the weight I sought to lose, my energy level went up, my brain fog has disappeared and I'm no longer pre-diabetic. It's a LIFESTYLE for me now. All I had to do was stop eating b'fast and cut back 99% of sugar and wheat. I substitute those two with alternatives that work PERFECTLY but don't spike my insulin. The world is OBESE now due to our amazing ability to grow abundant food. Sadly, the advertisers are shoving the WRONG foods into our faces instead of the right ones. If you take charge of your food lifestyle you will immediately begin to be healthy. It's your FOOD INTAKE that's killing you.

  24. When I try fasting after the 3rd day I start becoming paranoid. and I end up stopping it. Any one can suggest any help? Thanks

  25. Here's one for the atheists. If you fast for forty days and forty nights you can see God. But if you can't fast you'll miss out and always believe he doesn't exist. Too bad hey ?

  26. For me Exercise is the BB Gun to loosing weight. What you eat is pistol. When you eat is the big old double barreled shot gun to fixing your health. What's interesting, is when I don't eat my exercise increases, because I am full of energy. I can't stand sitting around. Time to go make a new flower bed or haul a ton of gravel or a truckload of mulch. I see so many people focus on the BB gun. They go out and run at lunch and then come back and have a cup cake. They could sit in there chair all day and skip the cup cake and be better off.

  27. I am thinking that he almost never eats. He is planning on living forever! But he looks terribly unhealthy to me. A chubbier person might not live as long, but they sure are easier to look at,….and probably more fun to have around.

  28. The NIH does not have a profit motive? You are funded by Politicians under the sway of lobbyists. That's how we got the food pyramid. You have a good message, tell the truth but don't pretend your an Angle because you are a government employee.

  29. I'm an older man and I've fasted for the last 20 years on and off. It works. My mental clarity after I fast is excellent. One problem I encountered was body odor. A few years back I was able to find Granny's Natural Deodorant. It's All Natural and Aluminum Free and it's the only natural deodorant that works for me.

  30. I like the way you speak. I have begun intermittent fasting and have felt better than I have in years. There is a lot of good scientific info on this on Youtube. Thank you for your work in this area of study and for presenting this material. Very nice that you passed on the joy of running to your son.

  31. I do it since 2012 and it's great. My mind has never felt so awaken, lucid and acute before in my life. Great talk.


  33. I hope everyone benefits from this talk. I have done intermittent fasting now for more than one year, every day in a pattern of 16-18 (fasting) / 8-6 (fed). I am 43 and feel like a teenager.Spread the world…!

  34. Weird. Every time I try fasting I get body jerks at night and feel like I’m getting Alzheimer symptoms.

  35. I'd much rather listen to health advice from real scientists than personal trainers or salespeople.

  36. Fasting truly should be promoted more. One of the first signs I've noticed about the benefits I've reaped came with my first menstrual cycle. For men, this might not mean a lot, but for women it's a great indicator of what's happening inside your body. No bloating, no pains, no stress, no food cravings. Nothing. I have lost weight, but the real reason why I've started fasting is mental focus and concentration. I find it easier to remember information and I'm much more motivated to get up and get things done. As a college student, this is something I struggled with in the past. Fasting+meditation have, without kidding or overreacting, changed my life for the better.

  37. notice the obligatory reference to evolutionary theory; the need to explain this from an evolutionary perspective. Which he did. Not.

  38. One part that stood out for me from this talk is how the ancient Egyptians created inscriptions 6000 years ago about Fasting.


  39. Jesus fasted for 40 days and 40 nights I want to do what Jesus does I fast for 2 to 3 days every month I’m 42 years old nothing hurts. I think fast i move faster.

  40. Alzheimers does not have a T sound in it!! Why is this word so hard for "professionals" to pronounce properly?

  41. could I make homemade ice tea with a squeeze of lemon and stevia for the summer I hate hot drinks in the summer?

  42. I got into a habit of having coffee at 4am before my 12 hour shift and just a La Croix water during my breaks and then eating whatever I wanted from 6-11pm. I lost 10 pounds in a week and wasn't hungry during the day. I feel sharper mentally and physically and it cost me nothing as the reason I started doing it was that I realized I was eating when I wasn't hungry out of habit.

  43. Intermittent fasting and keto saved my life. I couldn't even go a couple of hours without needing to eat and was a sugar addict. Lost weight, health issues disappeared (big ones). Absolutely saved me.

  44. I fasted for 6 days and 3 hours and the result was incredible,i became more sensitive to smell and i experience great mental clarity .Life became so easy,things start working better for me,i understand coding syntax more faster .my brain begin to function perfectly as if all the cobweb surrounding it are removed…I must confess that fasting is a powerful tool both physically and mentally.And another extra benefit is that i lost 5kg.

  45. This was my first encounter with fasting: this guy really went against the herd-mind at the time, but his TED talk allowed me to listen to IF advocates years later, without skepticism…

    …he saved my life.

  46. This runs counter to what our government used to say about learning. They said students need to have a breakfast provided by the school so they could learn better so they are now providing it at taxpayers expense. They probably have soda and candy machines in our schools too.

  47. I can’t hear a word the good doctor is saying over the din of his comb-over. Or should I say comb-around? I’ll have to start over, turn the screen off and just listen to it I guess. : )

  48. In Islam we’re encouraged to fast 2 days a week plus the 3 days when the moon is full.
    “Eat only when you’re hungry and if you eat, don’t get full”

  49. I'm totally convinced on this lecture. I have seen and felt exactly what he is talking about. Let me explain as quickly as possible. I have psoriatic arthritus. I feel pain in many places all over my body, every second of every day. I have an auto immune disease. During a 4 month period I felt like it was in remission. I was nearly pain free while lost 40 lbs, I went from 262 lbs to 222 lbs. I had changed my eating habits and was eating less food, not eating late and not eating junk. After the 4 months the pain returned and I also stopped losing weight. This was due to my move across country, as a result I changed my eating habits. After reading this and watching the video it all makes sense now. The lose of weight didn't just help my joints, tendons and ligaments since I was lighter, it actually helped my psoriatic arthritus disease. I will have to experiment now and see if it will happen again because I still need to lose at least 20 lbs more. Great video!!! Thank you!!!!

  50. have you worked with anyone suffering from Tinnitus. I have had this for 4 years and it seems to be getting worse. i have cut out a lot of foods breads, pasta's rice, limit caffine and sugar intake. I do fasting regularly. I havent tried fasting. searching for anything that can help.

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