18 November, 2009

Eat less to live longer

Drastically reducing the consumption of calories will increases the life span. This phenomenon, observed in many animal species, is known by the scientific community since the 1930s, because of laboratory animals subjected to calorie restriction live longer than their counterparts subjected to a normal diet.

This observation was so far remained unexplained. A U.S. study (Salk Institute) have identified a gene that plays a key role in increasing life expectancy when you eat less.

Caenorhabditis elegans (C. elegans)
Studies have been done in Caenorhabditis elegans, the nematode, a choice model in biology. Researchers have established a link between the two genes (called DAF-16 and SMK-1) and longevity.

Studies with mutants showed that the gene DAF-16 functions together with a gene involved in the development of the digestive system, PHA-4. PHA-4 is crucial for the longevity of the nematodes when they are subjected to nutrient restriction. Its deletion abolishes the ability of nematodes live longer when subjected to a hypocaloric diet.

The PHA-4 gene has a counterpart in mammals, Foxa. The manipulation of this gene could extend longevity in mammals and delay the onset of diseases associated with aging.