Our Longevity Diet

A study reported last month noted that researchers have known for a while that Type II Diabetes is associated with high levels of visceral (or Belly) fat, while subcutaneous fat (below-skin, especially in hips and buttocks) is not. The study found, surprisingly, that it was not the presence of belly-fat so much as the absence of subcutaneous fat that leads to diabetes. That is to say, visceral or belly fat does not have a negative effect, but rather subcutaneous fat has a positive effect on insulin sensitivity, which in turn correlates with the development of Type II Diabetes.

People who have high levels of both types of fat are at much lower risk for diabetes than those who have only belly fat. And those with only subcutaneous fat are even less likely to develop diabetes. The researchers suggested that subcutaneous fat may produce certain hormones, called adipokines, that produce beneficial metabolic effects.

Now another study was released that says pretty much the opposite:

Our study found lipid release from abdominal fat was substantially elevated during the night, which may be a primary mechanism leading to insulin resistance, a strong risk factor for type 2 diabetes.

This study seems on shakier ground, so far as the basic logic goes. They observe that belly fat releases lipids, and jump to the conclusion that this is related to insulin resistance — without any proposed (let alone observed) mechanism for it to do so. It is an observed correlation, with no known causality relationship.

This is a good example of why following the scientific studies can be so confusing. You need to look critically at these reports, and judge the probability of their being accurate. But often we lack the detailed information on study design and implementation that would allow us to accurately judge the results.

In any case, we may assume that if lipids from belly fat were related to insulin resistance, then intermittent fasting may exert a positive effect by limiting the release of lipids during fasting periods. Of course, that is just speculation — but it is consistent with the observed beneficial effect of intermittent fasting on insulin sensitivity.

A report today describes the autopsy results for the examination of the brain of a woman who died at the age of 115 years. There were absolutely no signs of atherosclerosis (narrowing of the arteries) or beta-amyloid deposits (a characteristic of Alzheimer’s disease).

The woman had undergone neurological and psychological examinations at the age of 112 and 113, and showed no signs of dementia or problems with memory or attention at that age. She was alert and involved, interested in national and international politics. She lived in a residential care home from the age of 105 due to poor vision, but her brain and intelligence compared favorably with people forty years younger.

I have not found any detailed biographical reports on this lady, so we don’t know her economic status or life history, but from her age we know she lived through the trying times of World Wars I and II, as well as the Great Depression. It is not too far-fetched to imagine that she experienced some caloric restriction and/or involuntary fasting during those years.

I have yet to see any studies on intermittent fasting that allow the subjects to go back to unrestricted diets after a period of time, and still continue to follow-up on health and longevity measures. My impression from the study reports we do have, however, make me think that calorie restriction or intermittent fasting during early adulthood may be more beneficial, in the long run, than the same diet initiated later in life. By the time we reach middle-age, much of the damage is done already.

Whatever the cause of this woman’s longevity — lucky genes or just a freak of nature — she is proof that degeneration of the brain is not an inevitable consequence of aging. Other studies show that challenging the aging brain to learn new things is one way to help stave off deterioration. We are hoping intermittent fasting will also help.

We have returned from our latest trip, and can report that we found it much easier to maintain our intermittent fast this time, compared to the previous short trip. We pretty much kept to the schedule except on two occasions, both of which were days we were actually on the road. The first day, we ate a little before the appointed time, because we found an attractive shady spot to stop — we brought sandwiches with us and so for convenience sake ate them about half an hour early. The second instance was the last day, when we came home again. We ate a sandwich at the bus station (we drove out, but left the car there and came back on the bus), but it wasn’t really a full meal, so when we got home we had a couple pieces of fried chicken from the freezer, even though it was three hours into our fasting period. So that fast was shortened to 20 hours instead of 23.

While we were at the cottage in Colima Isabel did the cooking, except for one day when we went to the beach and ate at a restaurant. Thus it was simple to follow our usual schedule, except for that one day at the restaurant. It was a day when we were breaking the fast with the meal, so as it worked out, we were about an hour late — so that fast lasted 24 hours instead of 23. Sitting under a palapa (thatched hut) on a tropical beach with the roaring surf and sun-glared beach made up for the extra wait. We have been fasting for three months now, so an extra hour here or an hour less there does not seem to matter much.

When we first started intermittent fasting we couldn’t wait for the clock to strike two so we could end our fasting period and begin eating. For the first week we even had a tendency to eat more than normal because we were ’so hungry.’ But soon reason prevailed, we slowed down our eating, and went back to normal portions. Now, after months of this routine, the exact time seems less important. We are hungry at 9:00 AM when we get up, but we know we will be no more hungry at 2:00 PM or 2:30 PM or 3:00 — when we eat. So the urgency has gone out of the meal which breaks the fast.

Just as a reminder to those new people joining us, our eating schedule consists of 23 hours fasting followed by 25 hours of normal eating, and is timed so that we eat our main meal at the same time (between 2:00 and 3:00 PM) every day. See the link at top right under our picture labeled ‘our diet’ for details. This is a non-calorie-restricted alternate day fasting schedule, so we eat as much during our daily eating time as we normally did before beginning the fast — yet we are losing weight. If you doubt we eat well, just take a look at the ‘april meals’ link just above ‘our diet’ and see what we had for most of April. That is typical of our eating habits since then as well.

More important than the slight and slow weight loss, is the fact that we feel better, and know we are doing good things for our future health. I am in a high-risk group for Type II Diabetes, due to my family history, age, and the fact that my extra weight is all belly-fat. I believe (based on animal studies) that this fasting schedule will help prevent my developing diabetes. It certainly has helped Isabel with her arthritis pain too. And I find I have fewer and milder head-aches, leg-cramps, colds and basic aches and pains.

This is an on-going experiment in lifestyle, so we will continue to keep you updated on our experiences. Meanwhile, to avoid repeating the same things over and over (we feel great, and it so easy!) I’ll be posting some analysis of the scientific studies being reported for fasting and calorie restriction diets, while trying to translate the scientific jargon into as basic English as possible. Stay tuned!