American researchers believe they have identified the genes behind the life-extending effects of calorie-restriction. Experiments on fruit flies by Stewart Frankel, of Yale University School of Medicine and colleagues revealed that strict dieting effects two genes known as rpd3 and Sir2. Frankel found that cutting calories leads to a decrease in the activity of rpd3, which is followed by an increase in the activity of Sir2 – a gene that has been linked to the life-lengthening capabilities of calorie restriction for some time. Scientists are trying to uncover the cellular mechanism behind calorie restriction in the hope that it will be possible to mimic its effects without having to resort to dramatically cutting back on food. According to Frankel, developing a drug that cuts the activity of rpd3 would be a much easier task than developing one that boosts the activity of Sir2.
SOURCE/REFERENCE: Science 2002; 298:1745
