April 19, 2004
this afternoon, one of the members of Calorie Restriction Society revealed that
he and 11 other members of the CR Society, plus 6 other non-members of the
Society who are also living caloric-restricted, have participated in a study
conducted by researchers at Washington University. The results were published
today in the Proceedings
of the National Academy of Sciences.(PNAS) and are being picked up by the
major media outlets. The results border on the phenomenal. The participants
average 50 years of age, and have been calorically restricted for 3 to 15 years,
with an average of 6 years. Tonight's BBC article, Strict diets 'cut heart disease',
says, "Levels of "bad" cholesterol and triglyceride blood fats
were very low in the people studied. And the group, whose average age was 50,
had blood pressure readings similar to that of the average 10-year-old.
Professor John Holloszy, from Washington University School of Medicine in St
Louis, who led the study, said: 'It's very clear from these findings that
calorie restriction has a powerful protective effect against diseases associated
The PNAS paper says,
"We studied 18 individuals who had been on CR for an average of 6 years (3-15
yr) and 18 age-matched healthy individuals on typical American diets. We
measured serum lipids and lipoproteins, fasting plasma glucose and insulin,
blood pressure (BP), high sensitivity C-reactive protein (hsCRP),
platelet-derived growth factor AB (PDGF-AB), body composition, and carotid
artery intima-media thickness.
"The CR group were markedly leaner than the comparison group (BMI, 19.6 ± 1.9
vs. 25.9 ± 3.2; % body fat, 8.7 ± 7% vs. 24 ± 8%). Total serum cholesterol
(Tchol), LDL-cholesterol, Tchol/HDLChol ratio, triglycerides, fasting
glucose, fasting insulin, hsCRP, PDFG-AB, systolic and diastolic BP were all
markedly lower, while HDL-Chol was higher, in the CR, than in the American
diet group. Based on previous medical record information, the CR group had
serum lipid-lipoprotein and BP levels that were in the usual range for
middle-aged individuals on typical U.S.A. diets, and similar to those of the
comparison group, before they began CR. Carotid artery intima-media
thickness was ~40% less in the CR group than in the comparison group. Based
on measurements of a range of risk factors, it appears that long-term CR has
a powerful protective effect against atherosclerosis. This interpretation is
supported by the finding of a low carotid artery intima-media thickness."
In other words, the "CRONies" were typical U. S. food-junkies a few years ago before they adopted a CRON diet.
This is a first pilot study with only 18 participants. It will no doubt be followed by larger studies, and by prospective studies which run for a year or two while the participants lose weight and work their way into a CRON diet, and then are measured. (Since my HDL level had risen to 71 and my triglycerides were 56 as of February before I had fully lost weight, I can attest to the efficacy of caloric restirction, at least far a sample of one.) Then, given the same kinds of results, I could see the American Heart Association cautiously pushing harder toward weight losss and at least modest caloric restirction. (And you have to practice serious caloric restriction to lose weight.) Alot of people responded to Nathan Pritikin and to Dean Ornish. Here's something that is far more dramatic. I predict that a lot of inviduals who are concerned about cardiovascular disease and Type II diabetes will begin to test the waters with calorie restriction. What's so significant about this is that it can happen within a few short years after adopting a lower-calorie diet. And in my book, this amounts to a partial reversal of aging.
This study focussed upon cardiovascular indices, but cancer, arthritis, Parkinson's disease, and all the other ills of aging are presumably also partially reversed, and partially held in check
The study's authors plan to publish subsequent papers detailing some of the other aging biomarkers that they found appeared to be reversed in the participants in this study.