By Sam WongYou are what you eat – so does eating old food make you old? It sounds far-fetched, but experiments on mice, flies and yeast suggest that it might.The fundamental causes of ageing aren’t well understood. A leading idea is that throughout life, our bodies accumulate cellular damage. That might include oxidative damage to cells caused by by-products of aerobic respiration, and DNA damage – or a combination of those and other types.Vadim Gladyshev at Harvard University wondered whether organisms might also be able to acquire cellular damage from their food.Food is broken down and used as the building blocks for many cellular processes, so eating older organisms – which have more molecular damage themselves – might cause an animal to age faster than one that eats younger organisms with less molecular damage.To test the theory, Gladyshev and his team grew yeast fed on culture media made from old or young yeast and fed fruit flies food made from old or young flies. They also studied mice fed meat from old or young deer. The animals were fed their particular diet from early adulthood for the rest of their lives.The old diet shortened lifespan by 18 per cent in yeast and 13 per cent in flies. In the mice, the old diet shortened lifespan by 13 per cent in female mice, but there was no significant effect among males.
You are what you eat: Old food shortens lifespan in animals