Cutting Calories Reduces Dangerous Inflammation
Non-obese people who ate 12% less showed benefits that might protect against chronic disease.
Eating less may help you lead a longer, healthier life, even if you’re not obese. New research reports that restricting calories by 12% in healthy non-obese individuals over two years significantly lowered markers of chronic inflammation. To maintain adequate nutrient intake within the context of lower caloric intake, participants were provided with a multi-nutrient supplement and an additional calcium supplement and counseled on maintaining an adequate protein intake. No negative effects on other parts of the immune system were observed.
Results from the large, multicenter study, led by researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University, were published in the journal Aging.
"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," says first and corresponding author Simin Nikbin Meydani, DVM, PhD, director of the HNRCA and of its Nutritional Immunology Laboratory. "This is the first study to examine these effects over two years on healthy, normal or slightly overweight 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."
INFLAMMATION’S DANGERS: Chronic inflammation has been shown to create successions of destructive reactions that damage cells, thus playing a major role in the development of age-related diseases such as cancer, heart disease and dementia. According to the Centers for Disease Control and Prevention (CDC), 7 of the top 10 causes of death in 2010 were chronic diseases, with heart disease and cancer accounting for nearly 48% of all deaths.
Because of the multiple risks from chronic inflammation, Meydani adds, "This may be one of the most powerful non-genetic interventions to slow aging, increase our health span and the quality of our lives."
LONG-TERM EFFECTS: After six weeks of baseline testing, 220 participants were randomized into two groups and further stratified by site, gender and body mass index. The control group maintained their normal diet for the duration of the study, while the test group was provided with support to maintain a high-satiety diet. The study targeted a calorie reduction of 25%, but participants actually averaged a 12% lower calorie intake.
Both inflammation and immunity biomarkers were measured at baseline, 12 months and 24 months. After 24 months, the test group had a significant and persistent reduction in inflammatory markers with no discernible difference in immune responses, compared to the control group. Some markers of inflammation were not significantly reduced after only 12 months, however; this delay suggests that long-term calorie restriction induces other mechanisms that may play a role in the reduction of inflammation.
Even smaller calorie reductions might help counter inflammation, suggests co-author Luigi Fontana, MD, PhD, of Washington University in St. Louis and Brescia University (Italy): "With all of today’s fitness and biometric measurement technology available to the public, it is certainly feasible for the average person to maintain a 10%-15% percent calorie restriction as a strategy for long-term health benefits."
TO LEARN MORE: Aging, online July 13 -