A leucine-rich diet could reduce age-related muscle loss, say French researchers who have reported positive results on rats. By supplementing the diet of young (8-month) and old (22-month) rats with 5 per cent leucine, the scientists from INRA’s Human Nutrition Research Centre in Auvergne showed that muscle loss was repressed in the older rats. The study also found that elevated levels of peptidase enzymes and proteasome subunits characteristic of old muscle were suppressed in 22-month old rats chronically fed a leucine-supplemented diet. A natural balance exists in adults between muscle breakdown and buildup. After a meal muscle loss slows down and synthesis doubles. However, as we get older this balance is upset and muscle breakdown begins to dominate. Annual muscle loss for people over 40 can be as much as two per cent.
