Feeding Rhesus monkeys a low calorie diet can greatly extend their lives, a long-term study shows. The study began in 1989 with an analysis of the monkeys’ usual diets. Then, the researchers broke the monkeys into two groups, and started cutting calories from one group’s diet. The group on the restricted diet were eventually eating 30% less calories than the control group. After 20 years, 37% of the control group had died of age-related causes, compared to only 13% of the monkeys’ on the low-calorie diet: The control group had three times the rate of age-relate conditions such as diabetes, cancer, cardiovascular disease, and brain atrophy.
Previous studies with yeast, worms, flies, and rodents have suggested that low-calorie diets can increase longevity, but this study is particularly important because Rhesus monkeys are primates, and so this suggests that humans could also live longer if they ate less calories. The authors note that a reduction of 30% from the baseline diet is not the same as malnutrition.
Of course, you can’t ask monkeys if they were feeling hungry all the time. But this study is one more reason for people to carefully examine their diets.
The study — “Caloric Restriction Delays Disease Onset and Mortality in Rhesus Monkeys,” by R.J. Colman and colleagues, will be published in Science magazine this week.