Caloric restriction extends life in monkeys, study finds

People who believed calorie restriction wouldn't extend life in primates might now have to declare themselves a monkey's uncle.

A 20-year study found that Rhesus monkeys fed a nutritious, low-calorie diet have fewer age-related diseases than counterparts on a normal diet, researchers report July 10 in Science. Also, MRIs reveal less shrinking with age in areas important for decision-making and controlling movement in the brains of calorie-restricted animals, report Ricki Colman and Richard Weindruch, both of the Wisconsin National Primate Research Center at the University of Wisconsin-Madison, and colleagues.
These results show that calorie restriction helps preserve primates' bodies and brains, says Luigi Fontana, of Washington University in St. Louis and the Italian National Health Service in Rome. Calorie restriction has already been shown to extend the lifespan of mice and dogs, as well as yeast, fruit flies and worms.

The findings may have ramifications for fighting aging and disease in humans, Fontana says. "I'm confident that everything that happens in [non-human] primates will happen in humans." Since both groups of monkeys are on a very healthy diet, people who go from a high-fat Western diet to a healthy, restricted diet may experience even greater health benefits than seen in this study.
The study began in 1989 with 30 adult male monkeys. In 1994, 30 female and 16 more male monkeys were added to boost statistical power. The monkeys were 7 to 14 years old when they entered the study. Since Rhesus monkeys live, on average, 27 years in captivity, it has taken this long to determine whether cutting calories by 30 percent would fend off aging and death.

Over the course of the study, monkeys on the full-calorie diet were three times more likely to die from an aging-related disease than monkeys that ate 30 percent fewer calories, the researchers found.

Since the study began, 21 of 38 control monkeys and 14 of 38 calorie-restricted monkeys have died. Of the control monkeys, 14 died of age-related causes, such as cancer, heart disease or diabetes. In the calorie-restricted group, only five died from aging-associated diseases, and none have developed symptoms of diabetes. The remaining deaths - seven control and nine calorie-restricted monkeys - were from complications of anesthesia, gastric bloat, endometriosis or injury.

"We were frankly blown away by these findings," Weindruch says.
Maximal lifespan for Rhesus monkeys is about 40 years old, so researchers won't know for another decade or two if - or for how long - calorie restriction can prolong life in primates.

Original report was modified by Jakub Málek.
Source: www.sciencenews.org