MEDFORD, Mass., July 15 (UPI) -- Reducing caloric intake may be an effective method of increasing the health of non-obese people because of its long-term effect on the body, according to a recent study.
Markers for chronic inflammation -- linked to age-related diseases such as cancer, heart disease and dementia -- decreased during a two-year study when people reduced their daily caloric intake by a quarter, suggesting long-term calorie restriction could slow aging, report researchers at Tufts University.
In 2010, seven out of 10 deaths was due to a chronic condition, suggesting the simple adjustment to food consumption, while otherwise maintaining the protein, vitamin and mineral levels, could be an effective way to improve overall health.
"Previous studies in animals and simple model organisms over the past 85 years have supported the notion that calorie restriction can increase the lifespan by reducing inflammation and other chronic disease risk factors, but with mixed results about whether it has a negative or null effect on cell-mediated immune responses," Dr. Simin Nikbin Meydani, director of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, said in a press release.
For the study, published in the journal Aging, researchers recruited 220 participants, separating them into two randomized groups, one maintaining a normal diet and one reducing caloric intake by 25 percent, with the second group also given multivitamins and mineral supplements to prevent malnutrition, for the course of the two-year study.
For six weeks before the start of the study, researchers took metabolic measurements of all of the participants to determine daily energy expenditure, inflammation levels and cell-mediated markers of immunity, taking new measurements at 12 and 24 months into the study.
The group maintaining a normal diet had relatively little change to inflammatory markers. The restricted diet group, however, had reductions in weight, fat mass and leptin levels at 12 months, with indicators of reduced inflammation being detectable at the end of the two-year study.
"This is the first study to examine these effects over two years on healthy, normal- or slightly over- weight individuals and observe that caloric restriction reduces inflammation without compromising other key functions of the immune system such as antibody production in response to vaccines," Meydani said.