If you haven't been practicing calorie restriction for most of your life, there's not a lot you can do (yet) about the irreversible damage done to your body so far - broken molecules and broken systems that cannot be repaired naturally. Aging is nothing more than the consequences of that irreversible damage, and you've been accumulating it faster than you might have been. That's past and done now. Still, it appears that adopting calorie restriction even late in life brings meaningful benefits:

Physiological changes associated with ageing include cell damage and the emergence of cancer cells. The most important effects of low calorie diets and longevity therapeutics given late in life may not be to prevent this damage, but instead to stimulate the body to eliminate damaged cells that may become cancerous, and to stimulate repair in damaged cells like neurons and heart cells. Low calorie diets drive the body to replace and repair damaged cells. This process usually slows down as we age, but low calorie diets make the body re-synthesise and turn over more cells - a situation associated with youth and good health.

No-one wants to develop cancer any sooner, or have their body run down years before it might; even if you've led the life of a gourmand up until now, why not look into calorie restriction? I noticed another report of basic research that lends a little more support to the position stated above:

Beneficial Biochemical Outcomes of Late-Onset Dietary Restriction in Rodents:

Dietary restriction (DR) or caloric restriction (CR) is the well-established means to retard aging, leading to prolongation of mean and maximum life span in many animal models. We have been interested in the possibility of extending the span of health of elderly people rather than increasing longevity, and therefore studied the effects of DR/CR initiated late in life in rodent models. We restricted food for 2-3.5 months in mice or rats of middle or old ages, which would perhaps be equivalent to 50-70 years of age in humans. We found that: (1) Potentially harmful altered proteins were reduced in the animals' tissues. (2) Extended half-life of protein in aged animals was shortened in mouse hepatocytes, suggesting improved protein turnover. (3) Reduced proteasome activity was upregulated in rat liver and skeletal muscle. (4) Protein carbonyls were decreased in rat liver mitochondria and skeletal muscle cytoplasm, and also oxidative DNA damage was reduced in rat liver nucleus, suggesting amelioration of oxidative stress. (5) Reduced apo A-IV and C-III metabolism in aged mouse was restored, suggesting increase in reduced fatty acid mobilization. (6) The carbonyl modification in histones that was paradoxically reduced in aged rat was increased to the level of a young animal, suggesting restoration of reduced transcription. These findings in rodents suggest a possibility that DR/CR is beneficial if applied in middle-aged or early senescent obese people. We argue, however, that application of late life DR/CR can be harmful if practiced in people who are already eating modestly.

It is interesting that the authors put that last disclaimer into the abstract, given the rest of the material in the paper and the evidence from human studies to date. It echos their position from the opening statement, the very mainstream characteristic of denying any desire to enhance longevity for fear of prejudicing future grant applications. The culture of gerontology has required people to hide behind the goal of extending healthy life in the aged without extending longevity - a goal the Reliability Theory of Aging and Longevity suggests is impossible - and ultimately led to a generation of scientists who bought into and believed this view. By doing so they would never support or work on science likely to actually extend healthy longevity in any significant way. Fortunately, this sort of thing becoming less common, as the campaign for increased support for deliberate efforts to extend healthy life spans continues, but you're still going to see it here and there.

But back to calorie restriction: the evidence for its benefits really are overwhelming. So much so that venture capitalists and other funding organizations are willing to sink hundreds of millions of dollars into producing knowledge and drugs that may have some of the same effects. Is eating less with optimal nutrition worth further investigation on your part? If you enjoy being alive and healthy to enjoy it, then very much so.

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Posted by Reason at April 28, 2007 9:39 PM | TrackBack (0)