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Intermittent fasting in mice improves long-term memory retention
- jasonhansel 5y agoAs a reminder: in mice.
- sedivy94 5y agoToken “in mice” comment. The underlying metabolic mechanisms ought to be comparable. This is far less nuanced than, say, a pharmacological study.
- d0mine 5y agoFasting for a day for a mice and for a human are completely different things (the human equivalent would more more like a week--and not eating every other week seems extreme)
- hourislate 5y agoA 24 hour fast for a mouse is like a 2 week fast for a human. Hard to say that this would result in the same outcome for humans. I've also read that lab mice are nothing like normal mice.
- TimSchumann 5y agoI mean, based on my extended fasting experience I'd say it's something that's worth exploring. I can't speak specifically to memory, but the mental clarity whenever I fast longer than a few days tends to be awesome. A seven day fast is something I'd encourage everyone who's otherwise healthy to try at least once in their life.
- tomjen3 5y agoThat sounds interesting. Do you have any tips or guides to get started, or is it more like “just stop eating”? I have never fasted for more than some hours before.
- joking 5y agoYou should have some salts to keep well hydrated, also be healthy and don’t have any problems like diabetes, or with your kidneys. Anything over 36-48 hours would be better to check with a doctor first.
- lloydjones 5y agoAnecdata: The only times I've got dizzy when '24h water fasting' are when I've been eating normal/high amounts of carbs in my diet around the fasts. I've been doing a few days/week of 24h water fasts again, but on a very-low-carb diet, and can report no dizziness whatsoever. An additional benefit (also mentioned by others) is that I don't have any insatiable hunger pangs on the water fasts (which I did when I attempted them on a normal/high carb diet).
- lloydjones 5y agoObviously your mileage may vary (etc etc), but for me, it's all about removing carbs. It's the difference between water fasting being (honestly) easy .vs. A herculean feat that I couldn't manage.
- DwnVoteHoneyPot 5y agoI'd start with "just stop eating" and then solve for any issues that pop up for you because people have a lot of different reactions. For me, I do alternate day fasting... sometimes 2-3 days of fasting in a row. I had some common issues such as not being able to sleep and diarrhea while fasting. So instead of 0 calories, I eat a bowl of oatmeal (high fibre) on my "fasting days". Also, when weight training while fasted I'd feel so light-headed I'd have to stop. But I fixed that by drinking 1 bottle of Gatorade (some calories + hydration + electrolytes) before exercise. You'll just have to find what works for you. Other patterns are 5:2 (2 days of fasting) and one-meal-a-day. Sometimes after a break from fasting, I'd get too hungry the first day back on fasting so I'd ease into it with one-meal-a-day.
- idontwantthis 5y agoI tried fasting Tuesdays and Thursdays for a few weeks in college. A couple weeks after I stopped I had severe and sudden dizzy spells for months. I’m not willing to try again unless I go hand in hand with a doctor.
- collegeburner 5y agoI wonder if there is any benefit from shorter periods, since I do not have the body fat to easily sustain a 2wk fast... also sounds like a good way to lose a lot of muscle?
- ReptileMan 5y agoThe body protects its nitrogen. You do lose some lean tissue mass but its relative share goes down with fast time (as long as you have the fat stores) and compared to a lean person it's less from the onset.
- rubatuga 5y agoThis is true, mice must eat much more often.
- tdaltonc 5y agoThis has got to be HN's favorite intermittent fasting meme. It combines a "well actually" with a false sense of mathematical precision - both are crack for HN. But it's more false than true. The truth in it is that mice lose a greater percent of their body mass in the first 24 hours. Also mice will die if deprived for food for ~5 days. So at 24 hours, they're much closer to death than a human. But that's not really what we care about with IF. Most people care about the metabolic transitions prompted by fasting,[0] which are strikingly homologous across mammals. The variance that does exist is pretty well captured by the models that underlie those metabolic stages. This article is about something going on in the brain, which is harder to assess in humans for obvious reasons. But one of the big benefits of fasting that kicks in around the 24 hour mark is macro-autophagy. We know macro-autophagy is occuring in the brains of mice by 24 hours [1] and we know that macro-autophagy has a similar time course in humans and mice in the tissues we're able to sample.[2] [0] https://usetemper.com/learn/metabolic-step-by-step/ https://usetemper.com/learn/metabolic-step-by-step/ [1] https://pubmed.ncbi.nlm.nih.gov/20534972/ https://pubmed.ncbi.nlm.nih.gov/20534972/ [2] https://www.tandfonline.com/doi/full/10.1080/15548627.2016.1271513 https://www.tandfonline.com/doi/full/10.1080/15548627.2016.1...
- moneywoes 5y agoSeems like there’s numerous conflicting studies regarding intermittent fasting especially when different fasting periods are taken into account. Is there any conclusive research regarding just having 2 meals a day? That seems to be the easiest to integrate in day to day life.
- sebow 5y agoI think there's a balance and there's definitely more nuance here.People should listen to their bodies, not go into extremes.Though the other extreme of over-eating through impulsive behavior is way harder to be aware of.Regardless of where someone starts on this 'diet', they should be aware of how they feel, but not be afraid of breaking the conditioning.
- scoot 5y agoPlease define conflicting (largely positive but under different conditions, or something else?), and list the studies in question. > having 2 meals a day Intermittent fasting isn't about reducing the number of meals, or in theory the total calorific intake, but rather the window in which food is consumed. That said, it's entirely possible that one influences the pother.
- JamesBarney 5y agoThe intermittent fasting in this study was every other day feeding by the way.
- swader999 5y agoI find that to be one of the hardest regimens.
- TimSchumann 5y agoAgree. I'd rather do One Meal A Day, or 5 days Fasting 2 days fed, or basically anything but every other day. Of course, I'm not locked in a cage in a lab with no choice.
- 5y ago
- eric_khun 5y agoDavid Sinclair (author of Lifespan) talking about Intermittent fasting benefits: https://youtu.be/jhKZIq3SlYE?t=2939 https://youtu.be/jhKZIq3SlYE?t=2939
- clockwork123512 5y agoI tried it for a while, but I never could make it stick (12-8 pm was my window). What worked for me for energy levels and mood was keeping it to a solid breakfast, lunch, and dinner of healthy food (high protein, no simple carbs) with no snacks in between.
- kk58 5y agoMental clarity is due to body entering Ketogenic state. You'd observe the same if you go on a keto diet It's easier if you first go on a keto diet and then you put your body through intermittent fasting
- sedivy94 5y agoKetosis requires fairly long, continuous periods of carb restriction. I’m not totally convinced that intermittent fasting windows are long enough to provoke ketosis. Im aware that ketosis isn’t a binary state, but it approaches being one, right?
- athorax 5y agoDo you have any evidence you can provide that intermittent fasting can actually induce a state of ketogenesis?
- dunco 5y agoI don't but you can buy breath or urine analysis devices/kits that will tell you if you are producing high levels of ketones so you could see for yourself.
- theshrike79 5y agoI wonder when the Apple Watch will get ketone detection. "Just pee on your watch" :D
- dunco 5y agohaha. we'll need a new Ingress Protection (IPee) rating to cover new fluids.
- colordrops 5y agoIs a ketogenic state something healthy to maintain continuously or should it also be intermittent? And are diets that invoke ketotis healthy long term? I can't seem to find much on this. It seems that a lot of the foods in keto diets have their own long term health drawbacks.
- SantalBlush 5y agoAnother study that doesn't adjust for lifestyle differences. Did they consider that the mice who fasted may have already been eating healthy, getting exercise, and avoiding alcohol? These things could also improve memory, and of course the article doesn't mention it anywhere. Great job, scientists. "It is difficult to get someone to understand something when their salary depends upon their not understanding it."
- no_butterscotch 5y agoThere seems to be a lot of pseudo-science around intermittent fasting. In particular I've heard people say things like "You can take black coffee", or "You can have sugar-free lemonade with no calories", or "As long as you don't consume more than 5 calories (or some other small number) your body remains in a fasted state". Yet I've heard in reality you can basically only consume water and nothing else during your fast in order to not break the fasted state.
- ivalm 5y ago> Yet I've heard in reality you can basically only consume water and nothing else during your fast in order to not break the fasted state I don’t think that’s true. AFAIK main thing is to not stimulate insulin production so while many sweeteners might break the state lots of things have effectively no insulin response (for example pure coffee).
- sudosysgen 5y agoWhat's the metabolic difference between black coffee and water that breaks the fasted state?
- throwawaycities 5y agoBlack coffee shouldn’t have calories, but it apparently does trigger metabolic responses in the brain, gut and liver. Most people debating things like coffee, tea, lemon, even fish oil (which definitely has calories) have lost the forest for the trees, and they often can’t explain why they are fasting in the first place or their goals.
- manmal 5y agoUnless you induce diarrhea, there’s food residues in the gut which keep adding to your energy bottomline for up to a few days. It’s unlikely that having a coffee or a supplement has a noticeable impact on your fasted state during intermittent fasting (when fasting 3+ days, things are different). To be sure, one could just measure serum insulin and ketone levels. Coffee will raise blood sugar, but it’s also lipolytic, so it’s both „bad“ and beneficial.
- carbocation 5y agoThere has been at least one rigorous (if small) trial of intermittent fasting in humans which found no significant benefit: https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2771095 https://jamanetwork.com/journals/jamainternalmedicine/fullar... Although not significant, the numerical data on the side of intermittent fasting certainly didn't seem to show a signal for harm, and maybe for benefit, so if you could figure out how to do this in a low-cost way, it would be interesting to randomize a larger group. (Still implies a small effect size.)
- Attummm 5y agoThe study you linked can't be described as rigorous. They only have 2 groups, without a control group. And they only give them the advice to eat between 12pm till 8pm, and the other group to eat 3 meals a day. They found there was significant decrease in weight for intermittent fasting group. The reason they give that intermittent fasting has no effect is because the other group also lost weight, although less. But since both groups got instructions the study is lacking a control group. Therefor we shouldn't compare both groups. What is left is to look at intermittent fasting by itself. And there they found what they call significant decrease in weight.
- carbocation 5y agoStudying human diet is notoriously difficult. Randomizing people who want to lose weight to 'keep doing everything how you have been' is not going to be a study that anyone enrolls in, so I think this study's methodology was thoughtful and realistic. The only genuine methodological critique I'm aware of for this study is its sample size.
- sydthrowaway 5y agoForget this, just use Anki.
- timdaub 5y agoAha, and so now this link is on HN and if questioned users would obviously deny the existence of this effect in humans until proven - still the assumption in the comments here is that this would work in humans too.
- 01100011 5y ago> a calorie restricted diet via every other day fasting So this isn't the same as the 'intermittent fasting' practiced by a lot of folks where you only eat in a short(8 hour) window every day. Personally I did the 8 hour window a couple times in life. After the last time trying it, I'm now "carb intolerant" and seem to suffer from reactive hypoglycemia and postprandial somnolence(i.e. dead after meals). IF didn't do anything for me, weight wise, so I can't really recommend it to anyone. YMMV.
- johnchristopher 5y agoCould reactive hypoglycemia and postprandial somnolence also come from bad lifestyle? At some point I was on that kind of schedule.
- Roritharr 5y agoThanks for pointing this out. Ever since I've done my first large stretch of the Keto Diet before the pandemic and lost roughly 30 pounds, I've developed a weak bladder. I don't know how this happened or if this is even remotely connected, but running to the toilet after every other glass I drink is something very unusual for me and certainly wasn't the case before the diet. Your comment just made me make the connection between the diet and the condition. I still think overall it's a net benefit to my health and I'll go back on the Keto diet in a couple of days to lose some more weight, but I think it's certainly possible there are some adverse effects that aren't really talked about or studied yet.
- robbiep 5y agoThe a major cause of a ‘weak bladder’ outside of prostate issues is urge incontinence, that is, just paying way too much attention to the sensation of needing to urinate and so having increased frequency due to that. In order to overcome this, it’s essentially training yourself to push longer and longer in order to reset your sensitisation. Of course, obvious disclaimer that I have no idea if this applies to you and your situation, but something to consider if you haven’t had this investigated. But keto with increased hydration could have inadvertently sent you this way
- bedobi 5y agoI really want intermittent fasting and low carb diets to have the benefits claimed, but having done both for extended periods on and off for years, if I'm perfectly honest with myself, the truth is I haven't seen any benefit at all, and a careful review of research in humans as opposed to rodents seems unable to back either of them up. Low carb especially for me anyway leads to undesired hormonal states with SHBG through the roof and just general prolonged brain fog and low performance and energy. (the opposite of what advocates claim) I do believe doing the occassional extended two-three day fasts for autophagy can be beneficial and anectodally I do see beneficial effects from those... but other than that I just eat varied healthy food usually three meals a day and I find that works best for my mental and physical performance, body composition etc. YMMV!
- ramoz 5y agoNot making claims about you, but simply skipping meals and eating more fat seems naive. & other things matter, like gender, other genetics, and your macros. YMMV, sure, because when I am low carb (less critical, more of a YMMV), high protein (critical), workout/lift (critical), count macros (critical) and fasting (less critical) I become the best version of myself. Mentally, physically.
- kilroy123 5y agoI've had the complete opposite experience.
- jeena 5y agoOne meal a day combined with keto helped me to lose 30 kg in 9 months practically without effort. As soon as I went off it (because of changes in life) I gained back 6 kg, now I'm at least trying to do OMAD but it's hard without keto, because the sugars make me hungry.
- coldtea 5y ago>and a careful review of research in humans as opposed to rodents seems unable to back either of them up. Well, research might not say that IF or low carb have X or Y benefits. They might very well not have any major benefit by themselves. But they very much say that lower BMI has tons of benefits, from heart to cognition. So if IF and/or low carb helps you achieve this BMI, then you should (and would) have had those other benefits too.
- q-base 5y agoI have been doing intermittent fasting with 8 hour "feeding window" for probably 10 years now. There are all sorts of different more or less believable facts about intermittent fasting. I won't get into any of them. I can just say that for me with my goals, it works. I can keep a lower bodyfat percentage while keeping muscle mass, year round than I could with any other "diet". My main issue with any other "diet" or philosophy has always been my huge appetite. When I ate 6 times a day I was always hungry because the portion size was too low. I have a huge appetite and loves to eat big portions. When I only have 2-3 meals a day, then they can be substantially larger. If you have trouble eating enough good food already, then IF is not for you. If you want the alleged health benefits, whether they occur or not, then try a day or two of fasting. But the daily fasting should only be used if it somehow fits your life, schedule and goals. The right "diet" is the one you can consistently adhere to.
- noneeeed 5y ago> The right "diet" is the one you can consistently adhere to. This is incredibly important. Having managed to lose a lot of weight, gradually, and then keep it off for several years, the key for me was finding something that fitted into my life and to which I could stick. I also gradually changed things, rather than doing a big-bang change. My problem over the last few years has been the effect of having children. Between the sleep deprevation and the change to my schedules I found it a lot harder to stick to my previous routines, resulting in me falling back into old habits. I'm now trying small changes, starting with at 10/14 routine, which I'll probably make more strict (8/16) in the future once it's become habitual. If nothing else I'm finding I sleep better than when I ate later in the day, which improves my will-power, and having a period of being hungry makes resisting snacks easier during the eating period. Good habits are hard to form and keep, and bad habits are even harder to break permanently. You have to be kind to yourself and take your time if you want those changes to be for the rest of your life. Losing weight is simple, but hard.
- amelius 5y agoMy problem with IF is that I need energy in the morning because of bicycle commute, and I also want to have a warm meal in the evening after I come back from work. This could only work if the feeding window was 10-11 hours wide.
- irthomasthomas 5y agoThis result seems to tie in with the mounting evidence of a link between diet and mind health. Specifically insulin response, which improves with fasting. E.g. Some scientists now calling Alzheimers Type 3 diabetes: https://en.wikipedia.org/wiki/Type_3_diabetes https://en.wikipedia.org/wiki/Type_3_diabetes According to two books I just finished, Lifespan and Why We Get Sick, even an 18 hour fast (skipping breakfast) is enough to see possitive improvements. Partly due to the dawn phenomenon, where our glucose and insulin rises with dawn and peaks around breakfast time, making breakfast the most dangerous meal, if your goal is avoiding fat storage.
- hoseja 5y agoI swear there's like two dozen "causes" for Alzheimer's.
- tdaltonc 5y ago> breakfast the most dangerous meal, if your goal is avoiding fat storage. That's counter to the evidence. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6658129/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6658129/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990470/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990470/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3756673/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3756673/ https://pubmed.ncbi.nlm.nih.gov/25724569/ https://pubmed.ncbi.nlm.nih.gov/25724569/ https://pubmed.ncbi.nlm.nih.gov/23512957/ https://pubmed.ncbi.nlm.nih.gov/23512957/ https://pubmed.ncbi.nlm.nih.gov/9040548/ https://pubmed.ncbi.nlm.nih.gov/9040548/ https://pubmed.ncbi.nlm.nih.gov/26948400/ https://pubmed.ncbi.nlm.nih.gov/26948400/ I recommend that most people skip breakfast because it's the easiest way for most people to fit a fasting window in around their work schedule. However, if you have more flexibility, it looks like there's a marginal benefit for body composition and metabolic fitness to having your eating window in the morning.
- irthomasthomas 5y agoI scanned them but I dont see which of these studies are testing the dawn phenomenon? Which is what I am talking about. https://en.wikipedia.org/wiki/Dawn_phenomenon https://en.wikipedia.org/wiki/Dawn_phenomenon
- toolslive 5y agoI've been on intermittent fasting for > 2 years now, and I don't remember my memory improving.
- coldtea 5y agoPerhaps it has improved but you don't remember how it was before... oh, wait...
- gundamdoubleO 5y agoI experimented with fasting almost a year ago now, from OMAD all the way to 6 day fasts. My only motivation was to lose weight and I figured working from home was the best chance I'd have to actually go through with it. I lost around 35kg and I'm finally at a healthy weight for the first time in my life. Of course I'm very happy with the results, but I didn't experience any benefits people mention concerning mental clarity or more energy. To be fair I also didn't feel much worse than usual after a few weeks of starting. What did give me more mental clarity and energy was eating well and exercising regularly, something that I had to come to terms with when transitioning back to a more traditional diet else I'd just end up putting the weight back on.
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- AlwaysRock 5y agoI love IF. It is hard for a lot of folks to get into though. Your body is used to eating three meals a day so for the first two weeks your body will get hungry during those meal times. You don't actually need those meals. Your brains has just been trained to expect them. So many people stop because they say they cant handle the hunger during the fasting window but... It goes away.
- tdaltonc 5y agoCheck out citravarin as a way to manage habitual appetite during that transition.
- cies 5y ago> Fasting is the willful refrainment from eating and sometimes drinking. Mice dont fast, they're being starved in captivity. Interesting results non the less.
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