Monday, July 5, 2010

Key To Long Life May Be Eating Proteins

New research may help explain why ‘dietary restriction’ (also known as calorie restriction) while maintaining sufficient quantities of vitamins, minerals and other important nutrients appears to have health benefits. These benefits include living longer. and evidence suggests that dietary restriction can have health benefits for humans, too, though it is unclear whether it can increase longevity.

To understand whether the health benefits of dietary restriction stem from a reduction in specific nutrients or in calorie intake in general, researchers at University College London measured the effects of manipulating the diet of female fruit flies. The results of the study are published in the journal Nature.

Adding methionine to a low calorie diet boosted fertility without reducing lifespan; likewise, reducing methionine content in a high calorie diet prolonged lifespan. Previous studies have also shown that reducing the intake of methionine in rodents can help extend lifespan. The findings indicate that it is possible to extend lifespan without wholesale dietary restriction.

Methionine is one of the most important amino acids essential to the formation of all proteins consumed when eating different food types, including meat and dairy products, soy-derived food such as tofu, and pulses. The relative abundance of methionine differs depending on the food type in question; it occurs in naturally high levels in foods such as sesame seeds, Brazil nuts, wheat germ, fish and meats.

Although the human genome has around four times the number of genes as the fruit fly genome, there is a close relationship between many of these genes. Since it is easy to create mutants and carry out experiments on fruit flies, the functions of many fly genes have been established and newly discovered human genes can often be matched against their fly counterparts. Therefore, even though the fruit fly does not on the surface resemble humans, many findings about its basic biology can be interpreted for human biology.

Research report prepared by the American Association for Long-Term Care Insurance the national trade organization committed to educating Americans about living long, healthy and protected lives.