Our Longevity Diet

One of the concerns about most calorie-restriction and  intermittent  fasting studies, is that they use animals, and they put them on the study diet when they first reach maturity, and continue until the animal dies or the study ends. That doesn’t translate into real-life human experience very well. A big question, for example, is whether or not intermittent fasting is beneficial if it is started later in life, rather than at early maturity.

A 2005 study titled Mitochondrial production of reactive oxygen species and incidence of age-associated lymphoma in OF1 mice: Effect of alternate-day fasting looks at older (i.e. ‘middle-aged’) mice to see if the know beneficial effects of fasting can be instigated later in life. Here is a quote from the abstract:

Alternate [day] fasting, that was initiated in middle age mice through a 4 month period, reduced significantly the incidence of lymphoma (0% versus 33% for controls). No remarkable difference was observed in the overall food consumption between alternate-fed (AF) and ad libitum (AL) mice, suggesting that the efficacy of alternate fasting did not really depend on calorie restriction.

This is good news, since many of the other beneficial effects of intermittent fasting observed in rodents have been confirmed in humans. The above study went on to observe that there was less oxidative stress observed in mitochondria of the fasting mice, compared to the control animals. This is the type of basic biological function that transgresses species, and may well function similarly in humans as in mice.

The focus of research in the past couple years seems to have shifted away from anti-oxidant behavior to particular  metabolic regulators and messenger chemical systems, but anti-oxidants have already demonstrated substantial beneficial effects on health and longevity. High anti-oxidant foods have the benefit of also tasting good, so it is no sacrifice to consume lots of them. When I lived in Michigan, my favorite was blueberries, but now that I’m in Mexico, those are hard to come by. Instead, I eat lots of chocolate — not sweetened, fattening, chocolate bars, but natural chocolate combined with spices and used as a sauce (check out Chicken Molé at your local Mexican Restaurant, for example). I also drink red wine for the ultimate anti-oxidant, resveratrol. Pomegranates, tomatoes, broccoli, garlic, spinach, tea and coffee, strawberries, and avocado are all high in anti-oxidants, and probably more beneficial than ever when combined with an intermittent fasting diet.

I have added an affiliate linked image to the ebook Eat Stop Eat in the right hand column here. While I don’t agree with every detail in this ebook, I think it is a good introduction to intermittent fasting. Of course, the author’s goal is weight-loss, so his program is intermittent fasting with calorie restriction. I think anyone who is more than slightly overweight can benefit from beginning such a regime, then relax the eating restrictions when you achieve your ideal weight.

Also, the author of this ebook (Brad Pilon) recommends an unbalanced eating schedule — you get more calories some days than others. As you know if you have followed this blog, we recommend a balanced schedule because it is much easier to follow. If you have the will-power to put up with an unbalanced schedule for a while, I’m sure it is a great way to lose weight more rapidly than our slow-but-sure method. So if you have a lot of weight to lose, it may be best to start with such a diet, before adopting a balanced 23 hours fasting followed by 25 hours eating lifestyle. Remember, this diet is not just (or even primarily) for weight-loss. You will be healthier, and probably will live longer, due to the beneficial effects of an intermittent fasting regime.

So if you are looking to lose weight, get the ebook. Remember that at some point, you will attain your ideal weight, and then you should switch to a maintenance schedule that will still provide the health benefits of calorically unrestricted alternate day fasting — such as our intermittent fasting schedule.

I’ve never been big on breakfast, at least not the tradition kind anyhow. As a kid I ate cereal before going to school because Mom insisted. When on my own, I gave all that up for one bottle of Mountain Dew. I know, no nutrition, but the caffeine and sugar woke me up, got me energized for the day and usually instigated a bowel movement (i.e. ‘morning constitutional’) as well. That was my breakfast from age 20 to age 48. Surprising my only chronic illnesses are slight rosacia on the nose and gout in the toes.

Oh, it didn’t end there — 48 is the age I was when I moved to Mexico. They didn’t have Mountain Dew here then (it has been introduced since), so I switched to Coke. Coca Cola is the Mexican National Addiction. If I ever need money here I plan to open a Coca Cola store and sell for 1/2 peso less than the going rate …

It was only a couple years after my 50th birthday that I finally gave up cola breakfast and began drinking coffee. Isabel and I opened a coffee-shop here in Chapala, using the covered patio of a friend with a lovely garden-sculptures-pool view. I had drunk a little coffee in high-school, but never made it a habit. Researching the subject for the coffee-shop, I was surprised to learn that coffee has actually been found to be healthy for you — the benefits of the anti-oxidant flavinoids outweighs any negative effect the caffeine may exert.

I switched to coffee for breakfast. At first with two spoons sugar in fresh-brew, or even sweeter Mexican Café de Olla — a delicious blend of coffee and chocolate with the brown-sugar piloncillo. Gradually I’ve cut back on the sugar since beginning fasting, and now drink my coffee without any additives. The fasting regime prevents me from eating my evening snack, so I have also begun eating actual food for breakfast, but it is still light — one pancake, piece of French Toast, or maybe Banana Bread, alternated with the less-starchy yogurt and/or fruit. Breakfast is only every-other-day, so I have a light starchy breakfast a couple times per week, and a fruity breakfast the other time or two.

Over on Dr. Eades Health & Nutrition blog, the current post is called ‘Big Breakfast Bunkum’ and looks at a recently reported study of the effect of a large breakfast on dieting efforts. As the title suggests, the good Doctor is skeptical of the report, and for good reason. This is a great example of how to evaluate a research report — he focuses on what is NOT said as much as on what the study claims. And the avowed interests of the prime researcher are not ignored. If funding had been mentioned (and it wasn’t) I might add that looking at that is another clue as to potential bias. I personally do not agree with Dr. Eades low-carb diet focus, despite the fact that I love meat and was never happier than when we tried out the Atkins diet (we both gained weight), but he does talk a lot of sense. I’ll be adding a link to his blog in the blogroll here…

Continuing our theme on intermittent fasting studies done on human subjects, today we look at a study called Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism, published in January 2005. In this study, eight men and eight women practiced alternate day fasting — quite literally — they ate one day, then fasted from midnight that day to the following midnight. The study lasted three weeks.

Before describing the results, let me jump to the author’s conclusion:

Conclusions: Alternate-day fasting was feasible in nonobese subjects, and fat oxidation increased. However, hunger on fasting days did not decrease, perhaps indicating the unlikelihood of continuing this diet for extended periods of time. Adding one small meal on a fasting day may make this approach to dietary restriction more acceptable.

This is almost exactly the type of diet Isabel and I follow, excepting the timing of the fast. I can just visualize those subjects waiting for midnight, then eating a big meal just before sleeping. Knowing they would fast again the following day, they probably ate a lot again just before going to sleep at the end of their eating day. So they slept with a full stomach — but were awake (and hungry) during all the difficult hours of the fast. As I’ve stated before, making this regime comfortable requires careful selection of the timing for your fast!

So, what were the results? Well, the subjects lost, on average 2.5% of their initial body weight, even though they were not restricted in how much they could eat on their eating days. In fact they were told they would need to eat ‘twice as much’ as normal to maintain their weight. Hunger, not surprisingly, did not decrease over time. I don’t know why anyone would expect that it might. Hunger doesn’t increase either — one is either hungry or not — with persistent intermittent fasting you get used to being hungry at times, but knowing food is coming soon makes it more bearable.

Measures of resting metabolic rate, respiratory quotient, glucose and ghrelin levels were unchanged, excepting that respiratory quotient decreased on the last day, which involved fasting longer than the usual 24 hours (the researchers obviously did not want the inconvenience of needing to test the subjects at midnight to get fasted results, so they had to fast until 7:00 AM the next morning as well). The only big change, besides the weight loss, was in insulin, which was down an average of 57% after the 31 hour terminal fast.

Obviously, this study was highly flawed in design. There was no measurement of what or how much the subjects ate on their eating days. Subjects even reported eating more than usual on their last eating day because they knew they needed to fast longer than usual afterwards! That alone undoubtedly affected all of the measurements taken.

One of the few Intermittent Fasting studies to use human subjects was Effect of intermittent fasting and refeeding on insulin action in healthy men by Nils Halberg, Morten Henriksen, Nathalie Söderhamn, Bente Stallknecht, Thorkil Ploug, Peter Schjerling, and Flemming Dela, published in July 2005. In this study a very small population of eight healthy men undertook an alternate day 20 hour fast for two weeks (kind of like Fast-5, but only every other day). They fasted from 10:00 PM one night to 6:00 PM the following night, every second day, so there was a total of seven 20 hour fasts over the 15 day period. They were instructed to eat more than normal on the non-fasting days, to maintain their weight, but not to change the types of foods they ate.

There was no significant weight-loss (as one might expect given the compensatory over-eating on non-fasting periods). Yet they did find significant improvement in glucose metabolism, especially insulin sensitivity.  They did not find evidence for the muscle-loss that had been observed in long-term fasts of 72 hours. According to the researchers:

This experiment is the first in humans to show that intermittent fasting increases insulin-mediated glucose uptake rates, and the findings are compatible with the thrifty gene concept.

By ‘thrifty gene’ they mean that our bodies are likely adapted to Late-Paleolithic eating habits. Indeed, in their introduction, the authors state:

Insulin resistance is currently a major health problem. This may be because of a marked decrease in daily physical activity during recent decades combined with constant food abundance. This lifestyle collides with our genome, which was most likely selected in the late Paleolithic era (50,000–10,000 BC) by criteria that favored survival in an environment characterized by fluctuations between periods of feast and famine. The theory of thrifty genes states that these fluctuations are required for optimal metabolic function.

Our take on this is that even very limited fasting, such as imposed by their study, can be beneficial for health. Our fasting schedule is really not much different, except it is slightly longer, 23 hours instead of 20, and our schedule is more balanced — which we find easier and much more comfortable — and we maintain it fairly constantly, not just for a couple weeks.

I find no reason to suspect our genetic adaptation to food intake during the Late-Paleolithic was substantially different from earlier times, when hunting-gathering also prevailed, so it might be more accurate to suggest we are still largely adapted to pre-agricultural food habits. No doubt we have undergone substantial adaptation during the past 10,000 years, but probably not enough to overcome the preceding 200,000 or more years.

In the past I’ve heard several claims that intermittent fasting can help prevent cancer, but in following the scientific literature, I’ve seen little evidence behind this claim. Now, someone from a discussion group brought this study to my attention:

Adult-onset calorie restriction and fasting delay spontaneous tumorigenesis in p53-deficient mice

Basically, the study not only shows that both calorie restriction and fasting can help make significant delays in the onset of cancer in mice bread to develop that disease (that’s what the p53 deficient part means), but they also show that the effect is present even when the calorie restriction or intermittent fasting is started later in life, rather than at adolescence. Too many of the existing studies of CR and IF look at the effects on animals that begin in adolescence and continue throughout their lives. I’d like to see more studies examine the effect of starting these dietary protocols later in life, and also the effect of starting early in life but then abandoning the protocol to return to ‘normal’ (i.e. continuous) eating.

And while the study shows cancer was ‘delayed’ rather than prevented, the difference is only semantic. Delay cancer long enough that you die of something else, and it has effectively been prevented. The mice were genetically prone to develop cancer — unless you have Li-Fraumeni Syndrome you are probably not so prone.

This study did show that calorie restriction was more effective than intermittent fasting, but the intermittent fasting regime used involved fasting just one day per week — it would be more interesting to see the results if ADF (alternate day fasting) were used. The bottom line seems to be that it is never too late to start benefiting from intermittent fasting. The beneficial effects are probably much stronger for those who start in early adulthood, but even us old fogies can reap some benefits.

Well, as mentioned in an earlier post, we were not here on June 4th or 5th when we would usually report our monthly weight results, so here about a week late are our weights, after three months and a week of fasting:

Isabel 61.0 kilos (started at 63.8 … 2.8 kilos lost)

Andrew 95.5 kilos (started at 99.1 … 3.6 kilos lost)

For those of you paying attention, you will remember that before our latest trip I was down to 95.1 kilos, so I’ve had a slight rebound of fourth-tenths of a kilo — nothing to be concerned about, my weight fluctuates that much on a daily basis. Compared to our weights five weeks ago, Isabel is down three-tenths of a kilo, and I’m down 1.4 kilos.

Remember, we undertook this intermittent fasting schedule for health reasons, and have made no effort to reduce our total amount of calories — we simply changed WHEN we eat. I continue to be amazed at the slow but steady weight loss, which is a very welcomed side-effect of our new eating habits. Isabel is nearly at her recommended weight of 60 kilos, and I’m almost half-way to my recommended weight of 90 kilos. I’m not really concerned if we reach those recommended weights or not, just so long as we stay in the nearby range. Under our old dietary practice we were gradually gaining weight with no end in sight.