Cutting calories has been shown to extend the life span of mammals, and now it seems a strict diet can even buy extra time for an already long-lived mutant mouse.

Scientists say their success in extending the lives of the unusually aged rodents was a surprise -- one that gives more weight to the idea that restricting calories can help people lead longer lives.

Illinois researchers describe their experiments with Ames dwarf mice, a type of mouse that lives 50% longer than their normal brethren thanks to the "longevity" gene they carry. These mutant mice are similar in some respects to normal mice whose life spans have been extended by calorie restriction.

To see whether calorie restriction could confer still-longer lives to the mutants, the scientists divided 2-month-old Ames dwarf mice into two groups: one allowed to feast at will, and one on a strict diet. They did the same with normal mice.

The investigators found that the dieting dwarf mice lived the longest of the four groups, while normal mice allowed to eat as they pleased had the shortest lives.

This certainly adds to the evidence that calorie restriction has a very impressive ability to prolong life. Experts suspect that the benefit of calorie restriction on life span has evolutionary roots. In times of food shortage, the body's metabolism adjusts to aid survival. And certain hormonal regulators of metabolism have been shown to help determine the life spans of flies, worms and yeast.

Nature November 22, 2001;414:412

Dr. Mercola's Comments:

Most will recognize that this is not a new concept. The evidence is quite compelling that if we lower our calorie intake we will live longer. Previous research has shown that a low-calorie diet works at the most basic level to extend life span and preserve health. This suggests that such a diet hinders ageing by slowing metabolism and reducing stress responses. What can your take home message be? I see so many people who tell me that they had trouble sticking with the eating plan. They say there just weren't any good foods available. Well, armed with the knowledge that eating less calories will likely increase your lifespan, you can comfortably and confidently choose to not eat anything, knowing full well that you are doing wonderful things for your body. Not only are you not putting in harmful things into your body which will promote disease, but the very act of consuming nothing is actually a powerful step in the direction of improving health. Obviously this can be taken to an extreme for some and if someone has an eating disorder like anorexia, this would not be a wise position to take. But with over 50% of the US population being overweight, most people do not struggle with this issue. Related Articles: Reduce Your Calories and Slow the Aging Process Insulin and Its Metabolic Effects