Antioxidants and Intermittent Fasting – Good For Longevity?

Are blueberry antioxidants beneficial for intermittent fasting? (Photo by Simply Bike)

Is it possible to live longer by combining the benefits of intermittent fasting (IF) and plant polyphenols? A new paper claims that taking polyphenol antioxidants during dietary restriction increases the lifespan of mice more than dietary restriction alone. The antioxidants used in the study were blueberry, pomegranate and green tea extracts.

The subject of the paper – "Potentiation of dietary restriction-induced lifespan extension by polyphenols" – is certainly enough grab the attention of anyone interested in life extension. The abstract seems promising too (link). Here's a quote:

Dietary restriction (DR) extends lifespan across multiple species including mouse. Antioxidant plant extracts rich in polyphenols have also been shown to increase lifespan. We hypothesized that polyphenols might potentiate DR-induced lifespan extension. [––] Polyphenol compounds may potentiate IF-induced longevity by minimizing specific components of IF-induced cell stress.

Let's look at these claims in more detail. First off, it's not clear from the abstract what exactly the authors mean by "dietary restriction". The full paper, however, reveals that they use the term to describe pretty much any kind of diet where access to food is limited, including traditional calorie restriction and intermittent fasting.

The longevity confusion

The problem with that opening sentence is that dietary restriction extends lifespan across multiple species only when it equals calorie restriction. That is, you can make a mouse live longer by only feeding every other day, as long as it results in less calories consumed. This is an important distinction, because many people – including longevity scientists – keep propagating the myth that intermittent fasting has the same benefits as calorie restriction. It doesn't. The reason that IF prolongs lifespan in some species is because the animals fail to compensate for the missed calories on their feeding days.

The next sentence is just as problematic. Yes, plant antioxidants have been shown to increase lifespan, but the question is, compared to what? So far, no one has succeeded in exceeding the known maximum lifespan of mice by feeding them antioxidants. Instead, what we see in many studies is that the antioxidant group lives longer than the control group.

The problem is that almost always, neither group lives very long. Poor diets, poor animal husbandry, poor environment – all play a role in how long the animals live. So, in essence, the antioxidants merely make the unhealthy mice a bit healthier. But this is like making a human live 70 years instead of 60 years by giving them some veggies with his daily bread and then claiming that "vegetables extend human lifespan".

Comparing lifespans

That said, there are some interesting figures in the full paper. The graph below shows the survival rates of the three groups; one fed the control diet, the second fed the same diet but only every other day, and the third fed a diet supplemented with polyphenols every other day:

There's a big drop in the survival rate of the control group around 22 months. For the IF groups, the survival curves look a lot better. So how does this compare to the average lifespan of similar mice kept in good laboratory conditions? Here's a graph of age ranges and survivorship of C57BL7/6J mice (the same strain used in this study):

This survival curve is based on a cohort of 150 male and 150 female mice. As you can see, at 28 months half of the mice are still alive. That's about 850 days, which is a pretty normal figure for mean lifespan of this strain of mice in the literature.

Once again, in the antioxidant study the control group dies earlier than is normal. For some reason, half of the mice are dead at 22 months instead of 28 months. One possible reason is the use of a high-fat diet to "mimic the effects of a Western diet", as the authors put it. This seems like a strange idea to me, because a typical Western diet is no more a high-fat diet than it is a high-carbohydrate diet. Furthermore, plenty of humans (myself included) seem to do quite well on a high-fat diet, whereas with mice it's somewhat different.

The survival curve of the IF mice in the first graph is slightly better than that of the normal-fed mice in the second graph. But that is hardly a surprise, given that both the IF group and the IF + antioxidant group had lower body weights than the control group. In other words, the intermittent fasting once again made the mice eat less than the control group, which in turn resulted in a slightly longer lifespan. It's good to keep in mind, however, that with just 10% calorie restriction longer lifespans have been reported in other studies, so the result is not too impressive.

Conclusion

Perhaps the most interesting result is that the IF + antioxidant group lived slightly longer than the IF group. There's no concensus as to whether it's a good idea to combine CR or IF with antioxidants. It may be that plant polyphenols are essential for optimal nutrition and good for activating sirtuins (which play at least some role in longevity), but there is also some evidence suggests that taking antioxidants may interfere with hormesis and thus diminish the effects of CR.

In this study, the antioxidants had a beneficial effect. While the IF diet by itself activated pro-inflammatory pathways, adding plant polyphenols to the diet blocked this effect. The authors identified 20 gene sets that were down-regulated by the addition of polyphenols, most of them related to immune response, inflammation, cell differentation and tumorigenesis. 

This suggests that if you're doing intermittent fasting, adding some blueberries, pomegranates and green tea to your diet may not be such a bad idea. Note, however, than the mice did not have access to polyphenols during their fasting days, so this study tells us nothing about taking antioxidants during fasting. It also doesn't say much about how polyphenols affect regular calorie restriction without IF in humans.

For more information on intermittent fasting and longevity, see these posts:

Lithium in Drinking Water May Lead to Longer Life
Does Intermittent Fasting Increase Lifespan?
Alternate-Day Feeding and Weight Loss: Is It the Calories Or the Fasting?
Slowing Down Aging with Intermittent Protein Restriction

Read More......

Nootropics, Longevity and More: The Year 2010 in Review

Comments or suggestions for the year 2011? Drop a comment! (Photo by Altus)

Happy New Year everyone! I hope your holidays went well and you're ready to make 2011 even better than last year. But before we do that, let's take a look at some of the best bits and pieces from 2010.

In January, I finally got a chance to see Aubrey de Grey for the first time. His presentation in Helsinki, Finland was mostly familiar to me already, but I enjoyed it nonetheless. Perhaps the most interesting part was when the audience got to ask questions; I thought Aubrey's answers were good, especially given that some of the comments were pretty frustrating (apparently some people think going through their entire family history somehow qualifies as a question). If you want to check out the presentation, the video is still available online through the link above. And in case you want to know more about Aubrey himself, he was also interviewed in Wired.com a while ago.

Nootropics are gaining more and more attention these days. Even 60 minutes ran a segment on students boosting brain power to do better in their studies. Amphetamine derivatives are still the most popular choice – but whoever comes up with an "organic herbal formula" that actually works as well as Adderrall is going to be rich. I also did an experiment with Ashwagandha to see whether it had a nootropic effect. It didn't, at least not the brand I was using.

And then there was the experiment with BioSil, the stuff that is supposed to make your hair and nails stronger. The science seems solid, but as I wrote in my conclusion, the price of the liquid supplement doesn't seem worth it, since orthosilicic acid, the active ingredient, is also present in my favourite beverage.

Speaking of hair, a lot of people have asked for an update on the soy isoflavones + capsaicin experiment, another one of my attempts at finding a magical hair growth formula that will make me filthy rich. The experiment has been going on for six months now, which is longer than the five months that the original study lasted, so perhaps a proper update is indeed due. So far I haven't seen much visible changes, however. I'm now adding various kinds of chili powders and pastes to almost all my foods, but I'm thinking of ordering capsaicin supplements to be sure I'm getting enough to match the study. And I also need another bottle of soy isoflavones.

I've tried a lot of useless supplements and topicals, but last year I came across something that really, actually works: retinoids. I've now been using them for over a year and I can really see the difference. My advice to anyone looking for real results is to forget about all the overpriced skin creams that are really nothing but moisturizers and go for tretinoin instead. Of course, since it actually works it's prescription stuff, so you can't just buy it from the store, you'll have to order it online and hope your package doesn't get confiscated by the customs officers who surely know better what you need than you do. Thank god for regulations!

Probably the longest and most throrough post of last year was about human hibernation and how it might relate to longevity. In addition to a look at the current state of hibernation science, there's also the odd legend of lotska, the art of hibernation allegedly practiced by poor Russian peasants:

At the first fall of snow the whole family gathers round the stove, lies down, ceases to wrestle with the problems of human existence, and quietly goes to sleep. Once a day every one wakes up to eat a piece of hard bread, of which an amount sufficient to last six months has providently been baked in the previous autumn. When the bread has been washed down with a draught of water, everyone goes to sleep again. The members of the family take it in turn to watch and keep the fire alight.

And of course, no post on slowing down metabolism would be complete without Indian fakirs and frozen mountain climbers. Check it out if you have the time, it's fascinating stuff.

While the Russian peasants may have spent most of their winter sleeping to avoid starving, there are also those who can eat as much as they like and still avoid getting fat. Even without any exercise. I'll let other bloggers fight it out over the details of the energy equation and whether a calorie truly is a calorie, but take a look at the BBC documentary in the link to see what I mean. Also check out the comment section, some interesting anecdotes in there.

How is the life extension movement doing these days? Well, the same old (and false) arguments against longer lifespans are still there, but the overall mood is pretty optimistic. Personally, I've noticed that younger people tend to be more open to the possibility of life extension than middle-aged people. Go figure. Meanwhile, the Russians have apparently found the cure for aging, although I haven't heard anything new on SkQ1 since September. But that's okay, because the next fountain of youth is already here.

Long-time readers of this blog probably remember that I did intermittent fasting for over a year. Part of the reason was that I wanted to see if 24-hour fasts could be done – I wanted to be the master of my hunger, so to speak. However, the most important reason were the studies showing positive effects from intermittent fasting without restricting total calories. You know, the whole "cleaning cells from junk through autophagy" thing.

But alas, after going through the studies more carefully, I was disappointed to find out that whenever intermittent fasting increased lifespan in mice, total calories had also been restricted. In effect, intermittent fasting extends lifespan only in conjuction with caloric restriction. Some of the other benefits of fasting may still be valid, to a degree at least, but without potential gains in lifespan, I don't see the point in doing a strict 24/24-hour cycle of fasting and feasting anymore. Besides, I now think that even full-blown calorie restriction would only give me a few extra years. Why? Because humans just can't do CR the same way rodents can. More on this later. Meanwhile, see my updated health regimen.

Of course, there were also several other posts which I didn't mention here; see the archives section in case you missed them. And just so you don't miss anything interesting in the future, remember to subscribe to my feed and to follow me on Twitter, which I use to post stuff (life extension, health, science) I don't have time to blog about in depth. Oh yeah, and tell your friends to do so too!

For summaries of previous years, see these posts:

10 Human Experiments of 2009 – Year in Review
7 Human Experiments of 2008 – Year in Review

Read More......

Does Intermittent Fasting Increase Lifespan?

Some say feasting and fasting will keep you younger. (Photo by bowtoo)

I often hear or read that intermittent fasting has all of the same benefits of calorie restriction. The idea is that by not eating every now and then while keeping total calories the same you would enjoy the same health effects as you'd get from simply eating less. Including living longer.

This mantra is repeated even in scientific papers, but is it correct? It's certainly easy to see the appeal: since actual calorie restriction means you're counting every calorie and going hungry for most of the time, intermittent fasting seems like a fantastic choice. Besides, the concept does make sense on the surface. Deprive your body of energy for a while, let autophagy do its work, and live longer. It seems to work for fruit flies and worms, after all, so why not humans?

Because humans are more complex. While simple species like roundworms can be very useful for screening life extension therapies, they are no guarantee that the same therapies work in humans. There are a million ways to extend lifespan in roundworms and fruit flies, but much less in rodents, and even less in humans.

Unfortunately, it looks like intermittent fasting (IF) is one of these cases. For obvious reasons, we don't have lifespan studies on IF in humans, but what we do have is studies on rats and mice. And, despite what the popular belief is, the data is much less promising than one might hope. The rather disappointing conclusion of the studies seems to be that intermittent fasting without caloric restriction does not extend lifespan. When it is accompanied by caloric restriction (CR), it does extend lifespan – and it looks like the degree of life extension is highly dependent on the degree of CR.

The reason you see studies showing increased longevity from IF in the first place is because most rodents eat less when they fast every other day. While humans generally compensate for a fast by eating twice as much the next day, mice and rats generally don't. They do eat more, but not twice as much – which means they are calorie restricted.

Don't believe me? Let's take a look at all the studies on intermittent fasting and longevity in mammals. Note that I've skipped all the alternate-day feeding studies that have not looked at lifespans. There are a lot of papers showing other kinds of health benefits from fasting (some of which are also a result of CR!) , and I'm not saying fasting is not healthy in general, just that it does not seem to extend life.

A critical look at the studies

The first paper I could find on the subject is from 1945 (link), not too long after the positive effect of calorie restriction on lifespan was discovered. This paper briefly mentions an even earlier study from 1934, in which mice fasted for two days in a row each week. The average lifespan of the fasted mice was slightly longer than those of controls, but the difference was not statistically significant. There is no mention of weight and food intake.

In the 1945 study, male and female Wistar rats were put on various versions of intermittent fasting. The rats fasted either one day in four, one day in three, or every other day. Fasting was begun at the age of 42 days and was continued until the rats died.

With the exception of females fasted once every four days, the average lifespans of all fasted rats exceeded that of the controls. The increase in lifespan was slightly greater in males than in females, although females still outlived males in general. In male rats, the most effective method was fasting every other day, while in females fasting once every three days gave the best results on average. However, both the male and female rat that lived the longest (1057 and 1073 days, respectively) were fasted every other day.

Food intake was not measured, but since the intermittently fasted rats weighed less than the control rats, we can assume that they also ate less. No drastic retardation of growth was seen, however. So, the first available study on intermittent fasting shows that when rats are intermittently fasted, they don't compensate for all the missed calories on the ad libitum days, and thus are CR'd, and therefore live longer. No big surprise there.

After this study, there was a gap of four decades before similar experiments were done again. During the 80's and 90's, three papers on intermittent fasting and lifespan were published by the same team. In the first one, male Wistar rats were fed either ad libitum or every other day since weaning (link). The mean lifespan of the fasted rats was 83% greater than that of the control group. And, just like in the 1945 study, fasting resulted in a lower body weight. The abstract doesn't mention the exact weights, but since the fasted rats took 75% longer to become fully grown, it looks like they ended up eating significantly less.

In the second paper, male Wistar rats were again fed ad libitum or every other day since weaning (link). This time they were also allowed voluntary exercise. The fasted rats exercised less in their youth but more when they were older. They also lived longer and weighed less than the control rats. However, in contrast to the first study, their growth duration was the same while growth rate decreased. That is, it looks like in the first study both groups eventually grew to the same size, while in the second study the IF rats remained smaller.

The third paper looked at the longevity effect of intermittent fasting (every other day) on three strains of mice, beginning at various ages (link). In two of the strains, mean and maximum lifespan increased and body weight decreased. The A/J strain, on the other hand, showed different results. When intermittent fasting was begun at 1.5 months, the mice lived longer despite not weighing less. When it was begun at 10 months, they again weighed the same as controls but actually died earlier. The rats that began fasting at 6 months weighed less than controls at some ages but showed no difference in lifespan.

Conclusion

In summary, it looks like intermittent fasting extends lifespan in rats and mice only when it is accompanied by calorie restriction. It does not mean that the animals are also put on CR; rather, they just naturally end up eating less (unlike humans, who tend to be very flexible and good at compensating for calories). And, in the rare cases that the animals actually do eat twice as much the next day, their lifespans are not increased.

For those who are doing IF for other reasons than life extension – such as improving insulin sensitivity or ">weight loss – this is not necessarily a concern. While some of the other health benefits reported in the studies are probably a result of calorie restriction, just like lifespan increases, I suspect IF even without CR still has some benefits in humans. It's just that based on the rodent studies, those benefits won't be enough to make us live longer.

For more information on diet and longevity, see these posts:

Dietary Supplement Increases Lifespan by 11% in Healthy Mice
Slowing Down Aging with Intermittent Protein Restriction
How to Live Forever: My 5 Steps to Immortality
Intermittent Fasting Reduces Mitochondrial Damage and Lymphoma Incidence in Aged Mice

Read More......

My Current Health Regimen v2.0

One of the changes has been an increased intake of fruit and vegetables. (Photo by YimHafiz)

This is my updated health regimen, aimed at adding a significant number of healthy years to my expected lifespan. As it's subject to change, I will keep this post updated accordingly. Major revisions (such as v2.0) will appear once a year or so; minor changes (such as v2.1) will be made as needed. With every major revision, I will move the post from the archives to the front page.

Since a long, healthy life is preferable to a short life by most people, following the regimen would make sense even without considering technological innovations. The true goal of my regimen, however, is to stay alive long enough to see rejuvenation therapies become a reality. In the long run, each year that I'm able to add to my expected lifespan now through things like dietary changes, exercise, and supplements, may grant me several extra years in the future.

Therefore, even those lifestyle changes that require considerable effort and resources while offering a seemingly limited benefit, make sense if one looks at the big picture. For a chance to see the world in 2090, I'm willing to skip the cheeseburger today.

My health regimen consists of four categories: diet, supplements, physical exercise, and brain health. All of the items under each category have some kind of scientific basis, and in contrast to my ongoing experiments, will remain a part of the regimen for the time being. Therefore, my current experiments are not a part of my long-term health regimen – unless they prove to be beneficial, in which case they'll be moved from ongoing experiments to the regimen.

Main changes from v1.0: none.

Avoiding harmful foods

The most important part of my diet is avoiding unhealthy things; increasing the intake of healthy things only comes in second. This is because preventing damage from happening in the first place is easier than repairing it later on.

I consider the worst culprit of modern diets to be an emphasis on grain products, fructose, and polyunsaturated fatty acids. There's considerable evidence to suggest that most people would do much better without them. Hence, things like pasta, rice, bread, candy, fruit juices, and most vegetable oils are off the daily menu. I only eat them rarely, and then simply because they taste good. For the past few months, I've allowed myself to eat whatever I want once a week (usually foods like pizza or fresh bread), which seems to be working well.

I originally cut back on my fruit intake, which used to be quite high some years ago, because I learned that fructose increases triglycerides especially in men, and fructose is not handled very well by the body in general. I later learned that fructose also forms AGEs much more rapidly than glucose, which kept me from reintroducing most fruits to my diet and eat berries instead, since they contain more nutrients per fructose calorie. However, I've now increased even my fruit intake a little, having read more about the AGE-inhibiting effects of phytonutrients found in fruit. I will expand on this later, but for an example of what I'm talking about, see my post about carotenoids inhibiting lipid peroxidation.

While much of this fits well with paleo dieting, I also diverge from the paleo diet these days. You may or may not remember that I used to be a potato hater back in the day, both because they could not be eaten raw (making them anti-paleolithic) and because of their high carb content. Basically, potatoes are just empty calories. But once you have your insulin sensitivity and blood glucose under control, I don't think a few potatoes now and then is much of a concern. At least they're low in fructose.

As you may recall, I followed a low-carb diet for the past year with an emphasis on paleo foods. I got on the low-carb, high-fat wagon in the first place to prove that eating a diet high in fat does not make you fat – and it didn't. However, this diet combined with my year-long intermittent fasting experiment resulted in a moderate-to-high intake of protein, the longevity effect of which I'm now questioning. To lower my protein intake slightly means eating either more fat or more carbohydrates, and since my fat intake is already very high, I've reintroduced some carbs into my diet. That is, I now occasionally eat potatoes not because I think they are necessary for health, but because they are low in protein. More on protein and longevity in future posts.

I still don't make nuts a dietary staple, because of their poor omega-3/omega-6 ratio and because I like to keep my PUFA intake low. That is, I aim not only for a good ratio of omega-3 and omega-6 fatty acids, I try not to eat too much of them in general. Omega-3 is particularly prone to undergo lipid peroxidation, and while nuts probably have micronutrients that protect them from oxidation to some degree, I'm playing it safe until I learn more.

Main changes from v1.0: slightly increased carb intake, slightly decreased protein intake, slightly decreased polyunsaturated fatty acid intake.

Eating healthy foods

Despite eating some more carbs these days, my diet is still fairly low in carbohydrates. My daily intake used to be around 100 grams; I have not measured my current intake, but I suspect it's around 100-150 grams these days. My main protein sources used to be meat, fish and eggs, but during the past year I've cut back on eating eggs because of their high methionine content. I'm still figuring out whether methionine restriction makes sense in humans, but in the meantime I limit my egg intake to 3-4 eggs a week.

Sources of fat, in the order of importance, are olive oil, palm oil, butter, cocoa butter, coconut milk, ghee, coconut oil, and sesame oil. Olive oil tops the list because I love the taste and because it's high in MUFAs but low in PUFAs and consistently does well in just about every health study. There may not be anything magical about MUFAs per se, but even if it's the polyphenols in olive oil that are behind all the positive health effects, olive oil still seems like a good choice. Palm oil is there because it's rich in tocotrienols (at least compared to other natural foods), low in PUFAs and high in SAs (making it suitable for heating), and because I've grown to like the taste.

Lard is off the menu for now because I ran out. Heavy cream has been replaced by coconut milk, partly because of dairy products increasing IGF-1, which may be bad for longevity (more on that in future posts). I don't eat cocoa butter raw (although I could, it's delicious), but I get plenty from all the dark chocolate I eat. Somebody asked me in the comment section why I eat sesame oil since it contains quite a bit of PUFAs, and noticing this was indeed so, I was going to remove it from my diet altogether. However, doing some reading I found that sesame oil seems to reduce markers of lipid peroxidation, so I kept it on the menu. I just use it for taste, however, so my intake of sesame oil is very low anyway.

Depending on my daily menu, anywhere between 50 to 70% of my total calorie intake is from fat. My daily menu has changed a bit, but percentage of fat is still the same. Most of this is saturated fat, which has been given a bad rep for reasons I believe are incorrect. I began reducing grain products and increasing my saturated fat intake years ago, and it hasn't killed me yet. In fact, my HDL has increased and my LDL has decreased on this diet. Triglycerides are not bad but could be better – a testament to my main vices, beer and wine.

There is one cereal grain I regularly eat, however: rolled oats. They're a convenient source of beta-glucan, which appears to be good for cholesterol and avoiding heart disease, and they don't contain gluten. Oats also contain quite a bit of quality protein. I used to eat them with milk and berries, but then switched to a combination of heavy cream and water to reduce my consumption of lactose and galactose (which easily form advanced glycation endproducts, AGEs). Now, I've stopped adding even heavy cream, because milk protein seems to interfact with the polyphenols in berries. So it's a mixture of coconut milk and water nowadays – not as good as cold milk, but still pretty good.

As for red meat, despite how it's portrayed in the media these days, I'm not convinced that meat consumption is harmful. Indeed, a recent review supports the hypothesis that processed meat, not meat in itself, may be harmful. The biggest problem I used to see with meat is the generation of AGEs. Though there is disagreement just how harmful consuming AGEs with food are, I tried to minimize the potential damage by avoiding overcooking and taking supplements. I no longer think AGEs in meat are a huge problem, however – more on this later. The reason I don't eat huge portions of meat like I used to is because of the high protein content.

And finally, the beverage department. I still love my daily coffee, which I drink 1-2 cups per day. Coffee has some nice health benefits too. Green tea is obviously staying on the menu; the studies showing positive health effects just keep on piling up. All in all, beer doesn't really belong to the "eating healthy foods" category, but even beer does contain some good stuff.

As you may recall, I used to drink yerba mate with meals to reduce the formation of AGEs. It's since come to my attention that yerba mate is carcinogenic at higher doses, so I now drink it only rarely. Green tea or black tea are safer bets, despite somewhat contradictory results in reducing AGEs and ALEs.

Main changes from v1.0: decreased egg intake, changes in the use of fats and oils, reduced yerba mate consumption, avoidance of lipid peroxidation.

A note on diet tweaking

It's much easier to point out things that are wrong in various foods than it is to prove something is healthy. These days, I'm more wary of advertising my diet as the best choice for everyone than I was before. Part of the reason is that the more I read and learn about nutrition, the more complicated everything becomes.

Case in point: I used to tell people vegetables are bad because, as an evolutionary strategy, they produce toxins to protect them from being eaten (which is true). Now, having learned of the importance of hormesis, I think vegetables are good because of those same toxins! I was also a huge fan of eating fruit (especially organic fruit) at one point, because it seemed to make sense from an evolutionary point of view. The, I got a little skeptical towards them because of their fructose content. Now, I think the benefits may outweigh the negatives.

All this, however, doesn't stop me from wanting to find the optimal diet for longevity. On the contrary, it's a healthy reminder not to get too emotionally attached to my health regimen, and to be ready to admit mistakes and make alterations as I learn more.

Going without food

The third key component of my diet used to be intermittent fasting. I stated in the first version of this post that "I may change my mind in the future, but for now I expect periodic food deprivation to remain in the regimen." That is still true to some degree: I no longer do a 24/24 hour cycle of fasting and eating, but I don't make it a point to eat three meals with snacks a day either. I often skip breakfast and lunch and eat only dinner.

The thing that lured me to try intermittent fasting was that there are studies suggesting that all or most of the benefits of chronic calorie reduction can be had by alternating zero calories with double the normal calories every 24 hours. While I no longer believe that IF is equivalent to CR, I do think that fasting in general is beneficial. An improved insulin sensitivity is a known result of intermittent fasting. Insulin sensitivity is associated with longevity, and among supercentenarians, insulin sensitivity is common.

Perhaps a more interesting thing about fasting is that it increases autophagy, a process in which the cell consumes a part of itself for energy. This can happen during ordinary cell maintenance, or when the body is deprived of nutrients. Since improved autophagy is at least in part why caloric restriction works, this makes other, less demanding forms of nutrient deprivation attractive options.

The reason I stopped doing strict IF is because I don't think there is much evidence that fasting for 24 hours and then eating for 24 hours is somehow optimal in itself. Most importantly, IF does not extend lifespan in most studies. Why IF is not equivalent to CR is not clear, but recent studies suggest protein may have a lot to do with it. My intermittent fasting diet resulted in huge meals with lots of protein, and I now suspect that this may have diminished much of the potential benefits.

Main changes from v1.0: no more 24/24 intermittent fasting, no more huge protein-heavy meals.

Supplements

The most important supplement in my regimen is vitamin D3. Most people are deficient in vitamin D, and the health benefits are so overwhelming that if there's one supplement I would recommend spending money on, it's vitamin D3. I usually take 5,000 IU of vitamin D3 daily, and at last check, my levels were at 45 ng/mL, which is in the optimal range. Now that it's summer, I'm taking 2,500 IU daily. I know some people take the same amount all year round, but since I do spend some time in the sun, I don't want to overdo it.

One of the supplements that has remained in the regimen since last time is vitamin K2, which is sort of a newcomer in the supplement scene but nonetheless has some impressive studies behind it. I'll write more about it in the future, but here's one study of interest for men: dietary vitamin K2 may reduce prostate cancer. Since fermented dairy products, which I'm not sure are the best choice for health otherwise, are the best dietary source of vitamin K2, I'm taking supplements instead. At the moment, I take 90 mcg of MK-7 (Jarrow MK-7) and 5 mg of MK-4 (Carlson Labs Vitamin K2) every third day in an attempt to find a balance between affordability and the long serum half-life of vitamin K2.

I used to take a tablespoon of fish liver oil daily, because it has lots of omega-3 fatty acids in bioavailable form (EPA and DHA) and almost no omega-6 fatty acids. A higher dietary ratio of omega-3 to omega-6 seems to be very beneficial in general, and fish oil has been shown to decrease inflammation. A commonly quoted optimal ratio is between 1:1 and 1:4, which seems to be close to how our paleolithic ancestors ate. As part of my plan to avoid excess PUFAs, I've dropped fish liver oil from the menu. I'm currently in the process of weighing the pros and the cons; it may be that a tablespoon per day will prove to be worth it in the end.

I also used to take resveratrol with quercetin during fasts to increase autophagy. I would still continue to take them, but unfortunately I can't afford all the supplements I might like to take (including AOR Ortho-Core, which is off the list for the time being), so I take resveratrol only occasionally. Meanwhile, I'm on the lookout for other things that increase autophagy. Curcumin is a cheap alternative, and it has other health benefits too, which is why I add turmeric to most of my foods.

Since my damn blender keeps leaking from the bottom, I'm no longer making smoothies every day like I used to. So these days I just add some ground flax seeds to my rolled oats for the flax lignans. Flax lignans may prevent hair loss, among other health benefits. Some people prefer to take them in supplement form, but flaxmeal is a cheaper and equally effective way to consume flax lignans. For best effects, they should be consumed twice a day with ~12 hours in between. Other things I do to prevent hair loss is use shampoos with ketoconazole and piroctone olamine.

Main changes from v1.0: no more fish liver oil, some supplement cutbacks due to costs, increased curcumin intake.

Exercise

My exercise routine is probably the weakest part of my regimen, compared to how much effort I put into diet and supplements. In the summer, I run for 30-45 minutes once a week to get some aerobic exercise (I should start again, since summer is here!) The goal is to keep the heart and lungs healthy, reduce blood pressure, and improve mood. In the winter, when it gets too cold for running outside, I go to the gym for strength training instead. Strength training reduces the risk of injury, prevents osteoporosis, supports joint health, and prevents muscle loss resulting from aging.

I also practice martial arts, which combines aerobic and strength training, to a degree. The main reason for me, however, is that it provides me with a basic set of self-defense skills and improves coordination. With aging, there is usually an increased fear of falling and hurting oneself – something children naturally don't have. Getting thrown around every week is a way to maintain a healthier attitude towards my body and prevent an irrational fear of getting hurt. I want my mind to rule over my body, not the other way around.

Main changes from v1.0: none.

Brain training

Any anti-aging regime should also take into account the importance of maintaining mental health. It doesn't take a genius to see that people who use their brains actively retain their cognitive abilities far longer than those who are passive.

One of the ways I keep the rational side of my brain fit is reading scientific papers and writing about them on this blog. I like logical problems in general, and I think practicing problem-solving skills are important for everyone, whether it's through work or hobbies. To train the creative side, I do things like play instruments, compose music, and read and write fiction.

My biggest problem is and always has been rather poor short-term memory. I don't know whether it's because my mind is always occupied with a zillion things, but it's more than once that I've gone to the grocery store to buy something I need and come back with something else entirely. This kind of absent-mindedness seems to run in the family. I believe it can be improved through training, however. The memory game experiment intends to increase IQ, but it improves short-term memory as well (I've pretty much forgotten about this experiment lately, by the way – I'll have to start playing again!)

Main changes from v1.0: none.

Quick summary of the health regimen

As a part of my diet, I regularly eat the following foods:

- Meat, fish
- Olive oil, palm oil
- Butter
- Vegetables, berries, fruit, oats, dark chocolate, coconut milk
- Coffee, tea, wine, beer

I limit or avoid eating the following foods:

- Grain products like pasta, bread, and rice
- Fruit juices, candy
- Vegetable oils high in PUFAs

In general, my diet is high in fat and lowish in carbohydrates. I consume saturated fat and monounsaturated fat liberally but limit polyunsaturated fats.

My supplement regime consists of the following:

- Vitamin D3: 2,500-5,000 IU daily
- Vitamin K2: 90 mcg of MK-7 and 5 mg of MK-4 every third day
- Varying amounts of green tea daily
- Flax lignans: 1-2 tablespoons of ground flax seeds daily

My physical health regime consists of martial arts, running (in the summer), and strength training (in the winter). For mental health, I do things that train the creative and logical sides of the brain.

For more information on anti-aging methods and living longer, see these posts:

Anti-Aging in the Media: New York Times on Caloric Restriction and Resveratrol
How to Live Forever: My 5 Steps to Immortality
L-Carnitine, Acetyl-L-Carnitine and Cognitive Function in Humans
Caloric Restriction Improves Memory in the Elderly

Read More......

How to Deal With the 5 Most Common Difficulties of Fasting

Can't get no sleep? Find something else to do. (Photo by babblingdweeb)

If you've tried fasting or are planning to do so, you're bound to run into at least some of the problems mentioned below. Based on my personal experience, they appear to some degree regardless of whether you're doing intermittent fasting or the occasional longer fast.

While these side effects of going without food may not be pleasant, the good news is that there are ways to deal with them. And, at the very least, knowing what they are beforehand helps you to prepare yourself mentally. Once you get acquainted with them, it becomes easier to detach yourself from them and to see them more objectively for what they really are: mere hurdles on the way to better health.

1. Feeling of hunger

This is the obvious one, of course. The feeling of hunger is the first effect to kick in once you stop eating. Depending on what and how much you ate prior to the fast, it may take anywhere between an hour and half a day before your stomach starts to growl again.

The key to tackling this problem is understanding how the feeling of hunger comes and goes during fasting. Many people who fast for several days at a time report that the hunger subsides after the first few days, after which the whole thing gets much easier. Thus, it may in fact be easier to do a 4-day fast once a month rather than a 2-day fast twice a month.

However, there is a definite hunger cycle noticeable even during one-day fasts (e.g. intermittent fasting or alternate-day feeding). I find that I usually experience my first hunger pang about 4 hours after the last meal. At this point, it's not even a feeling of needing more energy, it's just a slight craving to eat something, and thus pretty easy to ignore. Drinking something helps.

The cravings then disappear for many hours, and about 18 hours into the fast, a more serious hunger emerges. This is the point at which the temptation to break the fast is at its greatest. However, if you can force yourself to pull through, the hunger subsides after a few hours. Drinking coffee or tea is helpful; just don't forget to drink water also. Another efficient way is to find something else to think about. When you're concentrating on, say, your work or a hobby, you'll find that it's quite easy to go through this phase, and it's smooth sailing from there on again.

2. Fatique and brain fog

Well, almost smooth. With the disappearance of hunger comes a new hurdle: physical fatique and brain fog. At this point, the idea of eating seems appealing not so much because of cravings but because you find your energy reserves temporarily depleted. Sitting on a chair and staring at the wall seems like a strenous exercise. You can forget solving complex mathematical problems during this time.

As with hunger, the key is to know that these negative effects will pass. In fact, they will pass even more quickly than the hunger. I find that during a 24-hour fast, the brain fog and fatique start to subside after an hour or so. While focusing on something else is a good way to skip through the hunger phases, it's very difficult to focus on anything during the brain fog phase. Hence, I just tend to wait them out, staring at the cubicle wall in my fasting-induced trance. Trying to lift the fog with a couple of shots of espresso is... interesting. But don't take my word for it, try it for yourself.

A note about dry fasting (which is going without food and water): the fatique and brain fog phase seems to last much longer with dry fasts than normal fasts. Though you may go into ketosis quicker with this method, be prepared to endure some hours of fatique before the switch happens. I did not find any good way to get around this during my dry fast experiment.

3. Dry mouth

I must admit I haven't read that many reports about this particular difficulty from other fasters, but I frequently notice it myself. The obvious solution is of course to drink more water. It does indeed help, but I find that a dry mouth during fasting is not only related to drinking water but also to the lack of food itself. That is, no matter how much water you drink (and if you're not eating, most of it will just flush out quickly), the feeling of a dry mouth may persist. Still, the problem can be minimized with enough hydration.

My suspicion is that the lack of nutrients during fasting may explain this phenomenon; for example, on some days taking a magnesium supplement seems to help, and eating something even without drinking (after the fast, of course) often gets rid of the problem. Whether it's really related to dehydration at some level, I don't know. Tea and coffee are good ways to boost energy levels while on an empty stomach, but keep in mind that they also make the dry mouth worse. This can be relieved by drinking a glass of water for every cup of coffee or tea.

During dry fasting, this was a major problem for me. While it's easy to tell yourself that going without food is good for you and that the hunger will pass soon enough, it's much more difficult to do the same with water. Even half a glass seems so tempting that it takes quite a bit of willpower to endure the thirst and dehydration.

4. Sensitivity to cold

An increased sensitivity to cold is a common problem with those who practice (chronic) calorie restriction, but the "less energy, less body heat" rule applies to fasting as well. However, in the case of short-term fasts, the effect is only temporary. During the first 12 hours of the fast, nothing really significant happens, but from there on, the sensitivity to cold begins to make its appearance. The most pronounced effect is seen towards the end of the 24-hour fast.

Happily, this is probably one of the easiest problems to fix. If you're just sitting at your desk the whole day, the feeling of cold will creep up on you and make you wonder who turned off the heating. But once you've made it past the dreaded hour of brain fog, a great way to crank up the internal heat system is exercise. It's at this point that you begin to feel many of the positive effects of fasting: increased energy, improved mood, feeling of lightness, etc. I find my motivation to do some exercise is also enhanced.

I've tried both aerobic and anaerobic exercise, and the latter seems to me much more enjoyable towards the end of fasting. With running, I get exhausted fairly quickly compared to running after a breakfast, but with strength training I feel a tremendous boost in mental and physical energy compared to just doing nothing while waiting for the fast to end. I'm sure you won't break any records at weight lifting under a fasted condition, but for improving your well-being and avoiding the feeling of cold, strength training is highly recommendable.

5. Trouble falling asleep

This is a common problem with longer fasts and among those who have just started to do shorter fasts. With intermittent fasting, it may take a while to get used to going to bed without a dinner or an evening snack, but after an induction period, it's no problem. You may even find that you sleep better than you did before and need less sleep.

With fasts lasting several days, trouble falling asleep at night may persist. Especially if you're trying to call it a night while you're experiencing one of the more serious hunger pangs, you'll probably find it very difficult to fall asleep. You'll just be tormented by vivid images of cheeseburgers and bacon until you pass out from sheer exhaustion. With dry fasting, you can add cans of soda into the imagery.

While my experience is mostly with intermittent fasting, I've heard that the inability to sleep properly continues throughout the fast despite the fact that many of the other hurdles are already behind. So you'll spend your day feeling energetic and your night feeling, well, energetic. Some ways of relieving this problem are: drinking water to temporarily mask the hunger, avoiding caffeine well before bedtime, and drinking relaxing teas (such as rooibos). And of course, you can simply try to use the time for something more productive than sleeping!

Conclusion

Everybody probably reacts to fasting slightly differently, and the length of the fast will surely affect the degree to which you experience problems along the way. Nonetheless, based on my experiences and those of others, the above list describes most of the common side effects of fasting, along with suggestions on how to deal with them.

Here's a summary of the remedies in neat bullet points:

• Identify the hunger cycle and learn how to 'detach' yourself
  
• Drink enough water (especially if you're drinking coffee or tea)
• Do something that takes your mind off food
• Wait out the dreaded hour of brain fog
• Hit the gym to improve mood and avoid feeling cold
  
• Don't drink caffeine before bedtime
• If you can't sleep, do something else!

If you have other suggestions for ways to deal with fasting, share them in the comment section! For more information on fasting, see these posts:

Alternate-Day Feeding and Weight Loss: Is It the Calories Or the Fasting?
A Year of Intermittent Fasting: ADF, Condensed Eating Window, Weight Loss, And More
Slowing Down Aging with Intermittent Protein Restriction
Intermittent Fasting: Switching from Alternate-Day Fasting to Condensed Eating Window

Read More......

10 Human Experiments of 2009 – Year in Review

One of this year's big themes among bloggers was vitamin D deficiency. (Photo by Gail S)

Only a few days left until the end of the year, which means it's time to take a look at the inhuman experiments of 2009. For a summary of the experiments of 2008, click here.

1. Maca root experiment

The purpose of this experiment was to see whether taking maca powder increased energy and sex drive. While those who sell the stuff claim that maca is the ancient Incan remedy for just about every problem you can imagine, the scientific evidence behind it is more modest. That said, a couple of studies have indeed shown improved libido and increased sperm count from maca, so the claims are not entirely baseless.

Personally, I didn't notice anything different on the days I took maca, even in large doses. I speculated in the experiment conclusion that perhaps maca is only effective in those whose sex drive and energy levels are low to begin with. Another possible reason suggested by one of the studies is that only red maca is effective while yellow and black maca are not. The maca powder I purchased was yellow.

2. Retinol cream experiment

The retinol cream experiment was quite unique in the sense that it's one of the very few experiments that actually gave a positive result. The goal was to see whether retinol, the animal form of vitamin A, would improve skin quality. Since retinol is less harsh on the skin than retinoids, I thought it would be useful to try a retinol cream before moving on to the stronger stuff.

While the appearance of my skin didn't change visibly during the experiment, there was an unexpected growth of new hair on my left temple. I even took a few pictures to show I wasn't making it up. I'm not sure whether the effect was simply due to increased collagen production and skin cell proliferation or something else, but if you're suffering from hair loss, I would recommend giving retinol a go. As another experiment, I'm currently applying tretinoin on my face to see if retinoids are even more effective.

3. Tocotrienol experiment

Like tocopherols, tocotrienols are a form vitamin E. Most multivitamins contain only alpha-tocopherol, but it's the tocotrienols that seem to have all the interesting health benefits. Well, at least potential health benefits. One study reported an increase in hair growth in all subjects taking the tocotrienol supplement. Such a result seemed so unbelievable that I had to try it out for myself.

One major problem with this experiment was that tocotrienol supplements are not cheap, which meant that the duration of the experiment was only two months. As I wrote in the conclusion, I didn't see a visible increase in hair growth, but there appeared to be a reduction in the number of hairs lost daily. If I get my hands on an affordable tocotrienol supplement, I look forward to repeating the experiment to see if the reduction was due to tocotrienols or something else.

4. Topical vitamin C, vitamin E & ferulic acid experiment

In this experiment, I applied a topical consisting of ascorbid acid, vitamin E and ferulic acid on my face. All three compounds have some evidence behind them showing that they increase collagen production and improve skin quality. The product I was testing was called SkinCeuticals CE Ferulic acid, which is really expensive if you buy it the usual way; I purchased several smaller sampler bottles online, which was cheaper. Another way to save cash is to make a similar product yourself.

In the experiment conclusion I reported that I didn't see any improvement in my skin quality. A possible reason is that some of the liquid in the sampler bottles was apparently oxidised, which would render it useless. I concluded that it was not worth the price to keep using the product. However, some months later I read a book on skin aging that made me reconsider the whole thing, and so I decided to re-visit the experiment and order another set of sampler bottles. The experiment is still going on, and so far, none of the samplers have contained oxidised liquid.

5. Vitamin D3 experiment

As I'm sure you've noticed, vitamin D3 was really big in the health blogosphere this year. After reviewing the data I concluded that I've very likely been deficient in vitamin D3 for most of my life and decided to start supplementation. I know standing naked in the sun to get the required dosage is a big thing in the paleo circles, but at these latitudes it's not very feasible. Besides, sun damage seems to be a major cuplrit in skin aging.

For a few months, I took 2,000 IU per day and then increased to 5,000 IU. This got my serum 25-hydroxyvitamin D levels up to 113 nmol/L (45 ng/mL), which is in the optimal range. I'm still taking 5,000 IU daily, and while it hasn't given me complete immunity against all infections, this is the first experiment that has resulted in a reduction of colds. Not even intermittent fasting or the paleo diet did that.

6. Hyaluronic acid experiment

In a sort of continuation to my experiment with MSM, chondroitin and glucosamine, I decided to try oral supplementation with hyaluronic acid. Despite the high price, hyaluronic acid seems to be quite popular and is said to improve skin quality and promote hair growth. The evidence for oral supplements is shaky, however, except maybe for joint problems.

Because hyaluronic acid is so damn expensive, the experiment lasted for only a month, which is probably the shortest duration of any experiment on this blog. I didn't see any difference in skin quality or hair growth, but feel free the take the results with a grain of salt. I think hyaluronic acid may actually be quite useful, but next time I'd rather try applying it topically.

7. Tea tree oil vs. Korean red ginseng experiment

Now here was an experiment that seemed to go on forever. In this "classic" hair growth battle, Korean red ginseng and tea tree oil fought it out on my legs. Since Korean red ginseng (also known as Panax ginseng) has been shown to promote hair growth, and tea tree oil is supposed to be anti-androgenic, I was expecting ginseng to increase and tea tree oil to suppress hair growth on my legs.

After meticulous experimentation with various carrier oils and different parts of the body, I got sick of the whole thing and called it quits without ever seeing any results. You can read the "exciting" conclusion if you're interested in the details. All in all, I would think twice before adding these two to a hair loss regimen.

8. Intermittent fasting experiment

A couple of months ago I wrote on the blog that a year had passed since I began my intermittent fasting experiment. While I've occasionally experimented with different variations of the same thing, I have mostly followed the 24/24 hour cycle of feasting and fasting. That is, for most of the year I stopped eating at about 6 PM and then started eating again the next day at 6 PM.

After the last post describing my year on the diet, I've slowly returned towards a more "normal" way of eating again. Compared to other people, I still have lengthy periods of not eating, but I'm no longer on the strict 24-hour cycle. The main reason for the change is that intermittent fasting does not appear to increase lifespan like caloric restriction does, and life extension is my main interest, after all. For losing weight and improving insulin sensitivity it still appears to be beneficial, provided you do it the right way.

Beyond weight loss, however, I'm thinking there are better ways to incorporate fasting into my health regimen than the 24-hour cycle. Perhaps longer fasts done less frequently, perhaps periodical protein restriction. I'll write more about the subject once I do some more reading. Anyway, I feel pretty good about being able to follow my intermittent fasting routine so strictly for an entire year. Life extension or not, it surely taught me to think of hunger in a new, more positive way. The looks and comments I got from family members, friends, and strangers alike were pretty entertaining, too.

9. Emu oil vs. Hair Again experiment

This experiment was another battle between two hair growth products. This time the competitors were emu oil and a topical gel called Hair Again. Emu oil comes up every year in hair loss forums, but the fact is that the evidence behind it is very limited, to say the least. The commercial product, on the other hand, contained many ingredients that looked quite useful.

After eight months, I concluded that the battle had no clear winner, since there was no change on either side of my face. Yes, the hairs I grew with the retinol were still there, but no further improvement was seen. I still have some of the emu oil left, but I haven't found much use for it ever since I ran out of the topical gel. Sadly, even if I wanted to continue the experiment I couldn't, because the company that makes the gel refuses to ship to Finland any longer.

10. Nootropic experiment

The purpose of this three-way battle between taurine, acetyl-L-carnitine and ginkgo biloba was to see if any of them were effective as nootropics, either taken alone or in combinations. My subjective evaluation of my energy levels, mood, and ability concentrate would serve as the indicators. As an objective measurement, I compared my scores in a memory game meant to improve IQ.

For all the money I spent on these supplements, it's a bit of a disappointment that none of them seemed to do anything for me. As I wrote in the experiment conclusion, one possible reason why ginkgo didn't work is that the plant extracts may differ significantly among brands. Acetyl-L-carnitine and taurine, on the other hand, should be pretty much the same stuff regardless of the manufacturer. In the future, I may try another brand of ginkgo, and I'm thinking of using taurine to prevent glycation and hangovers. Further experiments may follow.

Conclusion

So there you have, the ten inhuman experiments of 2009. Once again, not many positive results, but hey, at least we've learned something, right? As you can see in the top-right corner of the blog under "Current Experiments", many of the experiments that started this year will continue into 2010, so stick around and see how they end.

Finally, I'd like to thank all the readers for your encouraging comments and questions during the past year – and for pointing out the mistakes, of course! You've been very helpful in making this blog better, and I hope the improvement continues the next year. Until then, happy holidays and take care!

Read More......

Alternate-Day Feeding and Weight Loss: Is It the Calories Or the Fasting?

Weight loss with one slice of pizza one day and anything you want on the next? (Photo by nettsu)

I don't know if you noticed, but a new study on intermittent fasting recently made headlines in several media. The paper basically found that alternate-day fasting (or "on-off fasting" as it was named in some articles) helped obese adults to lose weight.

That's not a huge surprise, really. If you're obese, it means you eat too much of the wrong foods and probably too often. Fasting every other day means you'll at least be eating them less often, if not less per se. However, the conclusions that have been drawn in various articles from the study seemed a little suspicious to me, so I decided to read the whole paper.

Indeed, the authors themselves appear to be somewhat confused as to what really caused the weight loss. So without further due, let's take a closer look at what the study actually found (link).

Study design

12 obese women and 4 obese men were recruited for the study. Mean age was 46 years, mean body weight was 96.8 kg, and mean BMI 33.8. Not exactly the featherweight league.

The study consisted of three phases. The first one was a 2-week control phase, during which the subjects were told to maintain their usual weight by eating and exercising as they normally would. In the second phase, which lasted for 4 weeks, all participants were given a standard menu containing 25% of their baseline energy needs on the fast days. On the feeding days they could eat as much as they wanted. The third phase, also 4 weeks, was similar to the second one. The only difference was that the participants could choose what they wanted to eat on their fasting days, as long as they only ate 25% of their baseline needs.

So, the first thing that sets this study apart from how most people do intermittent fasting is that they didn't consume zero calories during their fast. They just ate significantly less. The second thing is that the fasts began and ended at midnight. Most people (including me) start and end their fast sometime during the day, because it allows them to eat at least once a day. If the participants went to sleep before midnight, their "fasts" were significantly longer than 24 hours.

Their standard diets were also less than optimal in my opinion. Things like chicken fettucini, vegetarian pizza, chicken enchilada, cookies, and crackers aren't exactly paleolithic foods consistent with the idea of intermittent fasting. But then, this wasn't a paleo study, which explains why they were fed high-carb, low-fat foods. For the third phase, they were given diet tips by a registered dietitian:

On the ad libitum food intake day, subjects were instructed to limit fat intake to <30%> dairy options.

So more carbs and less fat once again. They probably took some of this advice and applied for their feeding days as well, which makes me wonder if they wouldn't have lost even more weight had they opted for low-carb foods instead. Still, as you can see from the results below, they did manage to lose weight even with this diet.

Results

During the first phase, there was no weight loss. This is unsurprising, since all the participants just kept on eating whatever made them obese in the first place. During the eight weeks of alternate-day fasting they did lose weight, however.

In the second and third phase the subjects lost weight at a rate of ~0.7 kg per week. At the end of the study, they had lost about 5.6 kg, most of which was fat. Mean BMI decreased from 33.7 to 29.9, while body fat percentage dropped from ~45 to ~42%.

Cholesterol levels were also reduced as a result of alternate-day fasting. HDL remained the same, but LDL decreased by almost 25%. This to me is a more impressive result than the weight loss, which I think could've been greater with proper food choices.

Systolic blood pressure was lowered by 4.4 mm Hg, but diastolic blood pressure remained the same. Heart rates varied throughout the study, but at the end, they were about 4 beats per minute lower than in the beginning.

Discussion

Okay, so everyone lost some weight and improved their LDL/HDL ratio on this modified version of intermittent fasting. But what exactly is behind these results? The first thing that came to my mind as I was reading the paper was: how much were these people eating on their feeding days? Surely that would have a drastic effect on weight loss.

Unfortunately, there's no mention of this in the paper. Yes, they were told they could eat ad libitum, but apparently they were not told to keep a record of what or how much calories they ate when they were not fasting. I know food diaries are generally unreliable (people tend to underestimate how much they eat), but it would've been better than nothing. The authors seem surprised that the subjects lost as much weight as they did:

We predicted that subjects would lose a total of 4.5 kg fat mass after 8 wk (on the basis of a 75% decrease in energy intake on the fast day, with no change in energy intake on the feed day). The actual fat mass lost (5.4 kg) exceeded our predictions.

With no change in energy intake on the feed day? I'm not sure where the authors got the idea that when you eat very little on one day, the next day you won't be extra hungry and compensate. That's certainly not my experience. On the contrary, I fully compensate for any missed calories by just eating twice as much the next day. Certainly not compensating can be done if one wants to, which may be what happened here:

This indicates that these subjects were also limiting their energy intake on the feed day, which may have occurred because the subjects knew they were enrolled in a weight loss trial.

On the other hand, some articles in the media (such as this one) have reported that there was a slight compensation going on:

On non-fasting days people typically ate between 100 percent or 125 percent of their calorie needs.

This statement is probably from a press release by the authors, but the paper itself is silent on the issue. In any case, if you're eating 75% less on one day and only 25% more the next, you're still 50% short.

That, in effect, makes this a study on caloric restriction, not intermittent fasting. How is it surprising in any way that people who eat half (or even less) than what they're used to manage to lose weight? Isn't that obvious? The amount of weight they lost is pretty much what you'd expect on a low-fat, calorie-restricted diet. And based on other studies, if they'd eaten more calories but restricted carbohydrates, they'd have lost more weight.

The whole point of intermittent fasting is that you don't have to restrict your energy intake, you just don't eat all the time. If energy intake is the same and yet there are health benefits, then we can conclude that it's the fasting that is behind them. If, at the same time, calorie intake is restricted, there's no way of knowing whether it's the reduced calories or the fasting that is the cause. And of course, if intermittent fasting leads to a voluntary reduction in energy intake, that tells us something too.

I have a feeling that eating the small meal every other day magically resulted in no hunger in this study. They were probably consciously limiting their food intake even though they were told they could eat as much as they want. The fact that the authors actually expected the participants to eat only their usual calories on feeding days makes me even more suspicious.

Try eating 500 kcal on one day and then seeing how you feel the next day. If you typically eat 2,000 kcal, somehow I don't think 2,500 kcal is going to cut it. I know it doesn't for me, at least not in the long term. As for this diet being much easier to follow than old-school calorie restriction (which the paper seems to suggest), I doubt it.

For more information on intermittent fasting and caloric restriction, see these posts:

Intermittent Fasting: Understanding the Hunger Cycle
Slowing Down Aging with Intermittent Protein Restriction
Caloric Restriction Improves Memory in the Elderly
Intermittent Fasting Reduces Mitochondrial Damage and Lymphoma Incidence in Aged Mice

Read More......

A Year of Intermittent Fasting: ADF, Condensed Eating Window, Weight Loss, And More

Even with intermittent fasting, you should watch what you eat. (Photo by Bryan Bruchman)

I can't believe it's been a year since I started my intermittent fasting experiment. By now, I've gotten so used to it that most of the time it doesn't even feel like an experiment anymore. It's become more like an integral part of my diet.

Which is a good reason to spice things up a little. As I wrote two months ago, I made a temporary change to the experiment and switched from my usual 24-hour cycle of fasting and feeding to a condensed eating window of 6-8 hours just to see what happens.

I found the smaller eating window even easier than alternate-day fasting (ADF). In practice it meant that I skipped breakfast and lunch, and then had a big meal and some snacks when I got home. While at work, I only drank water, coffee and tea. During a 24-hour fast I usually get very hungry and slightly dizzy at one point close to the end of the fast, but skipping breakfast and lunch did not result in a similar feeling of hunger. Sure, I ate with good appetite once I got home, but my energy levels did not drop at all during the day.

I didn't measure my calorie intake, but based on the fact that I gained a kilo during this period, I assume I ate as least as much as I did before. So personally, cramming all of the daily calories into a window of 6 to 8 hours was not a problem. I was already used to eating huge meals, and the eating window was big enough to include lots of snacks or even another meal.

For someone considering intermittent fasting for weight loss, I would recommend either 24-hour fasts or using a shorter eating window than I did. A daily 20-hour fast with a 4-hour eating period improves insulin sensitivity and levels of circulating adiponectin, which are key factors in regulating fat storage and thus weight gain. Further, most of the studies showing benefits from intermittent fasting used an alternate-day feeding schedule.

The implication is that while an eating period of 6-8 hours is probably superior to the usual combination of breakfast, lunch, dinner, and snacks (which keeps your blood sugar constantly high), fasting between 20 to 24 is the choice with more positive studies behind it. This leads me to believe that the most important thing is not how small the eating window is, but rather how long the fasting period is. That is, while eating for 1 hour every 12 hours would technically constitute as a daily eating window of 2 hours, I suspect eating for 2 hours and fasting for 22 yields better results. Whether a 2-hour feeding window and a 22-hour fast is slightly better or worse than eating and fasting for 24 hours is unclear, but what is clear is that both work and that the latter is much easier in practice.

That said, I've been able to both lose and gain weight during my intermittent fasting experiment, depending on what and how much I eat. Anyone who claims that IF allows you to gorge on junk food while losing weight is plain wrong. Combining intermittent fasting with a low-carb diet is, in my opinion, the way to go if quick weight loss is your goal. This way you're getting the insulin benefits from fasting and the lowered insulin response from consuming few carbohydrates.

Another crucial factor would be total energy intake during the eating periods. Based on personal experience and what I've read from other people, there's a tendency to "load up" on calories just before the fast begins, whether you're hungry or not. This makes the fast much easier, because you'll be digesting the food for longer and the hunger won't begin until late the next day. For anyone who wants to get the health benefits of IF (such as reduced mitochondrial free radicals, one of the seven types of aging damage) but maintain their weight, this is probably a good idea, but for anyone else, it can easily render attempts at weight loss useless.

To counter this, my suggestion is to follow the intermittent fasting routine but to eat only when you feel hungry. If the fast is about to begin and you still feel bloated from your previous meal four hours ago, so be it. Don't try to stuff yourself with food as a pre-emptive strike if you don't feel like it. You'll probably feel the hunger pangs earlier the next day, but it'll pass after a few hours, and you'll feel more energetic afterwards.

The take-home message of the above is that despite what you may have heard, intermittent fasting by itself is no guarantee you'll lose weight. It can be used for weight loss, weight maintenance or even weight gain, depending on the implementation: the length of the fasts, the composition of the diet, and total energy intake. By optimizing those three factors, you can shift your weight into any direction you want. By disregarding them, it becomes a genetic gamble.

IF improves insulin sensitivity, which is a good thing, but the relationship between higher insulin sensitivity and weight is not as straightforward as it might seem (more on that later). The easiest way to lose weight for most people is still avoiding a high insulin response in the first place. Reading other people's experiences with intermittent fasting, it seems that most of them have the best results when they combine IF with diets that don't contain refined carbohydrates (including whole grain products), such as Atkins or paleolithic nutrition. When unrefined carbs are brought to the table, the disagremeent over the superior diet begins.

I'm now switching back to my old way of eating and fasting for 24 hours. Further evidence may prove me wrong, but at the moment, I feel that it's more beneficial for overall health than a condensed eating window of more than 4 hours. Squeezing the eating window just seems like too much of a hassle for me, though some people on IF manage to do just that.

I've also done a small experiment with dry fasting (meaning no food or water) and ketosis in my search for the optimal form of fasting, but I'll save that for another post. Meanwhile, I warmly welcome you to post your own experiences with intermittent fasting.

For more information on insulin, fasting and weight loss, see these posts:

Green Tea, Black Tea & Oolong Tea Increase Insulin Activity by More than 1500%
A High-Protein Diet Is Better than a High-Carbohydrate Diet for Weight Loss
Green Tea Extract Enhances Abdominal Fat Loss from Exercise
Slowing Down Aging with Intermittent Protein Restriction

Read More......