Caloric Restriction and LongevityResearchers at the U S National Institute on Aging examined the role of restricting calories in slowing down the ageing process, and identified three salient indicators of caloric restriction: lower serum insulin levels, lower body temperature, and higher DHEA levels, according to a report from ABC Australia. Researchers behind the Baltimore Longitudinal Study on Ageing, which has been studying normal aging in healthy adults since 1958, decided to examine these three factors among survivors in their study group. They found that scoring well on any one of the three factors corresponded well with greater health and longevity. I’m not sure how close any of these are to being the primary cause of caloric restriction’s beneficial effects. Certainly if these things protect against diseases, and at least having a low insulin’s good because there’s less chance of getting diabetes and if DHEA protects against cancer and some of the other things, that would be beneficial. But in terms of the actual mechanism by which caloric restriction may be exerting its effects, these things may all be pretty much downstream, and just symptomatic of some more fundamental caloric restriction induced metabolic change. So it is not at all clear how much these factors contribute to longevity, and how much they are simply side-effects of other metabolic changes that are causing the longer lifespan. The fact that these factors are present in long-lived individuals who are not on calorie restricted diets gives some hope that it may be possible to develop drugs that mimic the effects of caloric restriction. If researchers can determine what factors are actually causal then that will greatly simplify the process of finding out which substances might have such a mimetic effect. |
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