Calorie Restriction and Longevity

An introduction to calorie restriction at h+ Magazine: "In the early twentieth century nutrition researchers found that rats maintained on reduced caloric intake showed lower spontaneous tumors compared to rats fed ad libitum (allowed to eat as much as they chose). Although this work did not address caloric restriction (CR) and aging, it suggested that CR might slow the onset of age-associated disease in rodents. ... Numerous follow-up studies demonstrated that a micronutrient adequate CR diet significantly increased the lifespan of many species, largely crossing species boundaries. ... While CR increases the lifespans of most species examined, it also suppresses many of the diseases associated with human aging, thus increasing the 'health-span.' Over short periods, CR lowers blood pressure, heart rate, and glucose levels, and improves memory in older individuals and measures of cognitive performance in animals. Over longer periods CR significantly reduces the risk for many different types of cancer, age-related brain atrophy, heart disease (and atherosclerosis related diseases), autoimmune disease, and adult onset diabetes. CR appears to lessen the risk for, and attenuates or even reverses the symptoms of Alzheimer's and possibly Parkinson's diseases; two major age-related neurodegenerative diseases that cause enormous human suffering. ... Interestingly, CR appears to promote the progression of Amyotrophic Lateral Sclerosis (Lou Gehrig's disease), indicating it does not protect from all human diseases. Aging causes extensive, often organ-specific changes in gene expression patterns. Analysis [has] shown that aging, calorically restricted mice show gene expression patterns resembling those of young animals, compared to ad libitum-fed mice of the same age. CR also lowers cellular oxidative damage by reducing mitochondrial oxygen free radical production, lessens age-related telomere shortening, lowers inflammation, increases DNA damage repair efficiency and lowers damage to DNA and RNA (thus promoting genomic stability), lowers insulin levels while promoting insulin sensitivity, reduces the number of senescent (non-dividing) cells that accumulate with aging, attenuates age-related cellular protein cross-linking, and increases the removal of damaged cellular proteins - a process called 'autophagy' which declines with age and plays a role in resistance to infection, cancer, heart disease, and neurodegeneration. "



I are sure there is some benefit of general calorie restriction in humans in contrast to the contemporary diet of excess common in the modern western world. But my gut felling is that rat studies are only maybe 30% applicable to human metabalism . No, I don't have any evidence of that estimate, just my opinion.

Some study of human Centurion BMIs throughout their lives contrasted with the BMIs of the general population would be much more persuasive to me than rat studies (I think it is fair to use BMI as a proxy for CR). Given the varying diets of the billions of people on the planet, a percentage almost certainly have been unwittingly practicing what would qualify as CR, if CR works in humans than there should be some examples of extremely long lived unwitting CR practitioners.

Posted by: JohnD60 at April 4th, 2012 8:55 AM

I've tried calorie restriction, but it makes me feel tired and light-headed all the time. I don't doubt its reported longevity benefits per se, but it certainly doesn't work with my physiology from a quality of life perspective. I await eagerly the development of real anti-aging technology.

Posted by: Jose at April 6th, 2012 8:04 PM
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