Science Magazine says, “It’s never too late”

A study published in the September 19 2003 issue of the journal Science (http://www.sciencemag.org/) showed that dietary restriction begun at any age increases life span—at least in flies. In this experiment, diets restricted in their quality (less sugar and yeast), not quantity, increased survival.

One of the most widely held theories in regard to the mechanism of action of dietary restriction in its ability to lengthen lifespan is that it slows the accumulation of aging-related damage. Although the technique does accomplish this, in this study, London researchers demonstrated that restricting the diet of fruit flies extended lifespan by reducing the short-term risk of death, and that the regimen could be initiated at any age to provide the same benefit.

The researchers placed one group of flies on a lifetime restricted dietary regimen and fully fed one group throughout their entire lifespan. Two additional groups of flies were fully fed up to their respective fourteenth and twenty-second day of adulthood, then switched to the restricted diet. Within forty-eight hours of the switch to a restricted diet, the flies’ age-related mortality rates fell to those of the dietary restricted group which were significantly lower than that of the fully fed group. The flies in the restricted groups also experienced an extension of maximum lifespan.

This study shows that the age-specific mortality rates of flies on restricted dietary regimens depends only upon their current dietary status and age, and that their past nutritional status had no effect, meaning that age-related damage accumulation was not a factor in this study. 

An accompanying editorial in this issue of Science entitled, “It’s Never Too Late,” offered the following optimistic viewpoint, “... Many still believe that death rates at older ages are intractable. This view is reinforced by evolutionary theories of aging, which emphasize that senescence is inevitable because the force of selection against deleterious, late-acting mutations declines with age. Research over the past decade strongly supports an encouraging alternative—that aging is plastic and survival can be substantially extended by various genetic changes and nongenetic interventions.” (Vaupel JW, Science vol 301, Sept 19 2003.)

***So how does this one differ with CR?.  I think it's safe to say that being paleo is a calorie restricted and diet restricted way of eating for us, in that, just eliminating processed foods, sugar, carbs, and offending foods, we're making optimum use of quality.  I think most of us ate far more calories on SAD than we do on paleo.  Oliva