FRIDAY, May 13, 2011 (HealthDay News) -- People who cut their daily caloric intake by 25 percent or more may live longer than those who do not, a new study suggests.
Researchers from the Washington University School of Medicine in St. Louis found that significantly limiting calories lowers core body temperature (the temperature at which all of the functions in the body can operate with maximum efficiency), which has been shown to prolong life.
The study, published recently in the journal Aging, compared the core body temperatures of 24 people in their mid-50s who practiced calorie restriction for at least six years to 24 of their peers who ate a standard Western diet with higher calorie and fat intake. The core body temperatures of 24 endurance runners in the same age group were also measured to determine if simply being lean was enough to lower body temperature without calorie restriction.
"The people doing calorie restriction had a lower average core body temperature by about 0.2 degrees Celsius, which sounds like a modest reduction but is statistically significant and similar to the reduction we have observed in long-lived, calorie-restricted mice," principal investigator Dr. Luigi Fontana said in a news release from Washington University. "What is interesting about that is endurance athletes, who are the same age and are equally lean, don't have similar reductions in body temperature."
Although restricting calories can double or even triple the lifespan of simple organisms, the researchers admitted it is not yet clear how much longer calorie restriction might help humans live. The study authors noted that those who practice the strict diet hope to survive past 100 years.
The researchers also pointed out that simply lowering body temperature isn't enough to increase lifespan. Fontana noted that how lower core body temperatures are achieved is important. "I don't think it ever will be possible to be overweight and smoking and drinking and then take a pill, or several pills, to lower body temperature and lengthen lifespan," he said.
"What may be possible, however, is to do mild calorie restriction, to eat a very good diet, get mild exercise and then take a drug of some kind that could provide benefits similar to those seen in severe calorie restriction," Fontana added.
The U.S. National Institute on Aging has more information on calorie restriction and longevity.