Getting the correct balance of proteins in our diet may be more important for healthy aging than reducing calories.
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fruit flies were fed a diet of yeast, sugar and water, but with differing amounts of key nutrients, such as vitamins, lipids and amino acids. The researchers found that varying the amount of amino acids in the mixture affected lifespan and fertility; varying the amount of the other nutrients had little or no effect.
In fact, when the researchers studied the effect further, they found that levels of a particular amino acid known as methionine were crucial to maximising lifespan without decreasing fertility.
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Amino acids are the building blocks of life as they form the basis of proteins. Methionine is one of the most important amino acids at it is essential to the formation of all proteins.
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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.
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In the past, we have tended to think that the amount of protein is what is important to our diet," says Dr Piper. "We've shown here that in flies -- and this is likely to be the case for other organisms -- the balance of amino acids in the diet can affect health later in life. If this is the case for humans, then the type of protein will be more important.
"It's not as simple as saying 'eat less nuts' or 'eat more nuts' to live longer -- it's about getting the protein balance right, a factor that might be particularly important for high protein diets, such as the Atkins diet or body builders' protein supplements."
http://www.sciencedaily.com/releases/2009/12/091202131622.htm