June 2, 2004 -- The drastic calorie cutting advocated by anti-a
June 2, 2004 -- The drastic calorie cutting advocated by anti-aging calorie-restriction diets may help promote longevity by activating a pathway that controls fat accumulation, a new study shows.
At least that's what researchers say they've found in mice.
Previous studies indicate that calorie-restriction diets may work in a passive way by reducing overall stress on the body, which reduces the risk of disease and may help people live longer.
But in their study, published in the current issue of Nature, researchers found calorie restriction triggers a molecular reaction in mice that reduces fat deposits and may promote longevity in mammals.
Calorie-Restriction Diet May Trigger Fat Gene
Researchers say prior research has shown that a gene called SIR2 promotes longevity in yeast. In this study, they looked at the mouse version of this gene, known as Sirt1.
The study showed that this gene is part of a system in mice that detects when food is scare. In times of starvation, the Sirt1 gene represses the activity of another gene known as the fat controller (PPAR-gamma). This gene controls the laying down of fat deposits.
In the calorie-restriction diets purported to promote longevity, researchers say the Sirt1 gene is activated and turns off the fat controller gene in order to breakdown fat and stop the accumulation of fat deposits. The reduction in fat storage provides a possible mechanism for understanding the regulation of mammalian life span by diet, they write.
Researchers say this may be the first step in explaining how drastic calorie-restriction diets may help mammals live longer lives, but the relationship between activating the body's fat machinery and human aging remains to be seen.
