Thin Monkeys Healthier, but Don’t Live Longer

In a 23-year study, cutting calories by one-third improved monkeys’ health, but didn’t extend their lives. Those results, published August 29, contrast with another recent study that did show longer life for monkeys on very-low-calorie diets. Other studies have found that earthworms, mice and other animals live longer with fewer calories. The new study included 120 rhesus macaques. They were randomly divided into two groups. One group ate a normal controlled diet. The other group ate about 30% fewer calories. The restricted diet included vitamin and mineral supplements. When the study began, 86 monkeys were young, up to age 14. The others were 16 to 23 years old. The average macaque lives about 27 years. After 23 years, the calorie-restricted monkeys weighed less and had lower rates of diabetes than the other group. The younger monkeys also had lower rates of cancer.