From The Harvard Gazette:
Researchers believe they’ve found the cellular link between extremely restricted diets and dramatically lengthened lifespan and hope to use the knowledge to develop new treatments for age-related diseases. The research, conducted by scientists at Harvard Medical School, Cornell University Medical School, and the National Institutes of Health, illuminates for the first time the cellular processes triggered by extremely low-calorie diets. Scientists have known for about 70 years that extremely restricted diets — where caloric intake is 30 percent to 40 percent below normal — can extend lifespan by as much as a third. In addition, those years are healthier and relatively free of common age-related debilities such as cancer, heart problems, and type 2 diabetes. The longer, healthier lives have been seen in a host of animals maintained on a very low-calorie diet, including mice, rats, and monkeys. What scientists haven’t been able to figure out, until now, is why eating a lot less makes one live a lot longer.
The answer, it turns out, lies in tiny bodies inside each cell that act as cellular battery packs. As one ages, cells lose these battery packs — called mitochondria — and slow down. Extremely restricted diets, it turns out, revs them back up again. The research, published in the Sept. 21 issue of the journal Cell, shows that calorie restriction sparks a chain reaction within cells that creates two enzymes called SIRT3 and SIRT4. The enzymes cross into mitochondria, making them grow stronger and increase energy output.
More here.
