If I say the phrases 'anti-ageing' and 'nutritional balance' to you, you'd probably think of the pages of quack websites selling untested supplements than the pages of Nature. And yet this week's issue has a study that actually looks at these issues with scientific rigour. It shows that, at least for fruit flies, eating a diet with just the right balance of nutrients can lengthen life without the pesky drawback of producing fewer offspring.
Despite the claims of the cosmetic and nutritional industries, chemicals or techniques that slow the ageing process are few and far between. We're a long way from any fountains of youth, but there is at least one conclusive way of extending an animal's life - restricting the calories it eats. It works in yeast, flies, worms, fish, mice, dogs and possibly even primates, but it comes at a cost. The dieting organisms had lower reproductive rates (technically, they had lower 'fecundity').
