Update On Calories and Longevity

This is an update of a previous post:
http://estelletobygoldstein.com/?p=50

Science keeps changing and moving forward so quickly that even an avowed knowledge addict like me can sometimes do little more than hang on for the ride.

Back when I wrote my earlier post, I already knew for sure that I wanted to live for as close to forever as possible.  Calorie restriction had been touted as one possible way to do do so, and change in the gut flora was one possible mechanism.

Since then, I have pulled together some older research and there has been some newer, and this is where it is at, now.

The link in that previous article goes to a research paper that suggests either high or low-fat diets can change the gut flora, and that such mechanism might account for an alleged increase in longevity.  Sounded interesting.

Since then, there has been lots of water under the bridge, not to mention lots of food down the gullets.

First, in terms of gut flora, it is so hard to change that I am not recommending a probiotic to anyone unless it has a bunch of different strains, a minimum of 8 billion organisms, and a person plans to take it for 6 months.  I feel I need to know a whole lot more about calorie restriction before diving in.

Second, I have been back to the data from the “starvation diet” experiment run by Ancel Keys at the University of Minnesota, with conscientious objectors from World War II.  36 young men went from 3200 calories a day to 1570.

This link leads to a detailed description of what became called “the starvation experiment.”

By the time I showed up at the University of Minnesota for my fellowship in neurology in the early 1980s, people were still talking about how “crazy” all these test subjects were.

It is bad enough that the data from this experiment tied low fat intake to low fats (cholesterol and triglycerides) in the blood, an error subsequent studies have fixed.  But there is something still about a “cult” of people who want to eat less and live forever.

Turns out calorie restriction longevity studies have been done on multiple species since about 1930, as reviewed by the folks at the National Institute of Aging.  They seem to be correct in that the results for species including the human seem to be all over the map — clearly not enough evidence for me to think of recommending ths to a human.

A University of Wisconsin and National Institute on Aging study of Rhesus monkeys over 23 years shows not only increased longevity and some health benefits for monkeys, and looked at some possible reasons why.

Gut flora are now acknowledged to an important factor in everyone’s health — but wait, there’s more!

The lower calorie diet monkeys seemed to have more of a protection from diabetes, arthritis, diverticulitis, cardiovascular illness, and even cancer — but there were differences between Wisconsin and Washington D.C. were enough  that there have got to be a bunch of environmental and other factors.  The monkeys were on different kinds of feed.  Besides, benefits were not as great when this was started in older age instead of youth.

The first comment here is the correct one.  All of this study, like lots of research, is done calculating from a high carbohydrate diet — 56.9% carbohydrate, 17.3% protein and 5% fat.

Carbohydrate restriction improves health.  Research endorses this.

Fasting, even the most intermittent, can be helpful to a number of aspects of health, and may well, like carbohydrate restriction, be working at least in part through intestinal flora.

Dr. Mark Mattson of the National Institute on Aging, has been researching this for years.

Although I never did locate that original M.I. T. caloric restriction study I heard about in childhood, I did find this curious report on an M.I.T. website.

I am cautious about people who jump into anything too fast, too hard, and too much. Nobody doing ANY of the calorie restriction studies I have seen looks at psychology. People can become wildly irritable with cholesterol too low, and could be inducing eating disorders by choosing this lifestyle.

For now, I am pretty squarely behind lowering carbohydrates alone, for a lot of reasons about which I plan to speak more.

After all, that is how I have reversed my own obesity, diabetes, and hypertension.

In these aspects — if not generally — I can be called “normal!”

The End