Pima Indian Study: Low-Cal Diet Increases Life Expectancy
A new study to appear in the Journal of Clinical Endocrinology & Metabolism (JCEM), which evaluated 652 non-diabetic, healthy Pima Indian volunteers over a period of 11 to 15 years, sheds new light on the connection between caloric intake and life expectancy.
People who consume fewer calories may live longer, whereas people who eat more and have higher metabolic rates age faster and die younger, Science Daily reported.
"We found that higher endogenous metabolic rate, that is how much energy the body uses for normal body functions, is a risk factor for earlier mortality,” said Reiner Jumphertz, MD, of the National Institute of Diabetes and Digestive and Kidney Diseases in Phoenix, Arizona, and lead author of the study, according to Science Daily. "This increased metabolic rate may lead to earlier organ damage (in effect accelerated aging) possibly by accumulation of toxic substances produced with the increase in energy turnover."
The conclusion is relative to one's metabolic rate, not energy expended during physical activity, reported WebMD. Jumphertz said the findings highlight why “reductions in metabolic rate, for instance via low calorie diets” may benefit one's health.
Researchers tested the volunteers from the Arizona-based Salt River Pima-Maricopa Indian Community in a 24-hour energy expenditure at rest in 508 volunteers and resting metabolic rate in 384 of the volunteers over a period of 11 to 15 years (during the study period, 27 participants died of natural causes).
“You have a higher energy metabolism if you have a lot of body fat,” endocrinologist Loren Wissner Greene, MD, a clinical associate professor of medicine at New York University Langone Medical Center in New York City, told WebMD. “Obesity increases risk of early death and the mechanism might have something to do with increased metabolic rate and free radical production.”
The article, "Higher energy expenditure in humans predicts natural mortality," will run in the June 2011 issue of JCEM, stated the news alert.