Study: Low-Calorie Diets Don't Boost Longevity - Food Product Design

BETHESDA, Md.?A new study conducted by scientists at the National Institute on Aging (NIA) at the National Institutes of Health (NIH) suggests following a calorie-restricted diet may not prolong longevity or reduce age-related deaths as previously thought.

The study, published in the journal Nature, concluded calorie restriction does not extend years of life or reduce age-related deaths in a 23-year study of rhesus monkeys; however, calorie restriction does extend certain aspects of health.

The survival results in the study reported today by NIA researchers differ from those published in 2009 by NIA-supported investigators at the University of Wisconsin-Madison. The Wisconsin study followed two groups of rhesus monkeys for 20 years and found that monkeys on a calorie-restricted diet lived longer than those on a standard diet.

Beyond longevity, the parallel NIA and Wisconsin studies have reported similar beneficial health effects of calorie-restriction. Both studies found that certain age-related diseases, including diabetes, arthritis, diverticulosis and cardiovascular problems, occurred at an earlier age in monkeys on the standard diet compared to those on calorie restriction. However, this observation was not statistically significant in the NIA study. NIA researchers did find that monkeys started on calorie restriction at an early age had a statistically significant reduction in cancer incidence.

The researchers also found that while calorie restriction had a beneficial effect on several measures of metabolic health and function in monkeys who were started on the special diet regimen during old age (16 to 23 years), it did not have the same positive outcome for monkeys started on calorie restriction at a young age (less than 14 years). In the Wisconsin study, all the monkeys were 7 to 14 years when started on calorie restriction.

"These results suggest the complexity of how calorie restriction may work in the body," said NIA Director Richard J. Hodes, M.D. "Calorie restriction?s effects likely depend on a variety of factors, including environment, nutritional components and genetics."

Differences in the monkeys' meal and other nutritional factors were cited as possible explanations for NIA?s and Wisconsin?s different outcomes. Both studies used a similar percentage of calorie restriction with their intervention groups; however, the Wisconsin monkeys in both the calorie restricted and control groups were eating more and weighed more than the matched NIA monkeys.

NIA's food had a natural ingredient base, while Wisconsin opted for a purified diet. Purified diets generally lack trace dietary chemicals and minerals that could affect an animal?s health. Each ingredient of a purified diet provides a specific nutrient and minerals or vitamins must be added separately. Natural-ingredient diets have risk of variation between batches, but are considered by some to be more complete than purified diets. NIA and Wisconsin also used different sources for proteins, fat and carbohydrates, as well as different approaches to vitamin and mineral supplementation.

Source: http://www.foodproductdesign.com/news/2012/08/study-low-calorie-diets-don-t-boost-longevity.aspx

weather gina carano at last al green burger king delivery etta james at last john king