New findings published in the journal Nature have found that the key to healthy aging may in fact lie in the proper balance of proteins in your diet. Researchers discovered this possible connection to protein intake by studying, of all things, fruit flies. By varying the amount of amino acids (the building blocks of proteins) in their diet, they were able to affect the longevity as well as the fertility of the flies.

The results shed light on the phenomena of calorie restriction, which is the process of reducing your intake of food while maintaining proper levels of vitamins, minerals, and essential nutrients. It has been repeatedly observed that restricting calories has numerous positive health consequences, which include metabolic, hormonal, and functional benefits. In certain animals models, it has even been shown to increase life spans, though the exact mechanism of how or why this happens is not clearly understood, nor has it been determined that it applies to people.

In fact, it appears that one specific amino acid, methionine, seemed to have the most significant impact. Under proper conditions, changing the amount of methionine in their diet led to significant changes in lifespan. Interestingly, changes to their dietary intake of other key nutrients, including vitamins and lipids, did not seem to have any effect.

Methionine is a key amino acid in that it is essential in the formation of all proteins. It is not produced by the body and must therefore be obtained from the foods we eat. Good sources of methionine include sesame seeds, Brazil nuts, fish, and meat. Most vegetable sources of protein, including legumes, are low in methionine.

While at first glance, one might think that what affects fruit flies has nothing to do with humans, it is important to keep in mind that calorie restriction phenomenon is evolutionarily conserved. In other words, it affects everything up and down the food chain, from simple organisms like yeast and flies as well as more advanced species like monkeys. Furthermore, though we are markedly different than flies, there is a close relationship between many of our genes, so what affects their life cycle can be in fact be relevant to the study of human health and biology.

The exact mechanism of how calorie restriction works is still not known, but there is a growing school of thought that believes it is linked to the decreased levels of insulin that result. This, however, has yet to be proven, though there are aspects of calorie restriction that are components of actual healthy dietary regimens, including the Okinawa diet and the CRON diet.

Before embarking on any sort of modified eating plans, speak to your physician or a professional dietician.