Eat less or eat well?

Researchers from the newly founded Max Planck Institute for Biology of Ageing in Cologne have studied whether health benefit stem from a reduction in specific nutrients or calorie intake in general by manipulating the diet of female fruit flies. The 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 scientists were able to show that longevity and fertility are affected by a combination of the type and amount of amino acids; whilst varying the amount of the other nutrients had little or no effect. Furthermore, the researchers found out in previous studies that levels of a particular amino acid - methionine - were crucial to increasing lifespan without decreasing fertility. By carefully manipulating the balance of amino acids, both lifespan and fertility were maximised. For the first time, this indicates that it is possible to extend lifespan without wholesale dietary restriction and without lowering reproductive capacity.

I suspect that continuing research will show that this is still too simple, that manipulating methionine levels is a blunt instrument, and that the issue is balance among the various nutrients rather than the amounts. My expectations - perhaps bias - comes from experience as a grower. It is often the case that better growth and more healthful produce comes from getting the nutrient balances in tune with one another in a context of nutrient availability rather than from broad manipulation of total nutrients or even targeted provision of selected nutrients.