moderate caloric restriction in healthy non-obese people reduces chronic inflammation -
Eating less may help us lead longer, healthier, according to new results a large multicenter study, led by researchers at the Jean Mayer USDA Human nutrition Research Center on aging at Tufts University. The paper, published in Aging , reveals that restricting calories by 25 percent among non-obese healthy people over two years, while maintaining protein, vitamins and adequate intake of minerals can significantly lower markers of chronic inflammation without negatively affecting other parts of the immune system.
"Previous studies in animals and simple organisms models over the past 85 years have supported the idea that calorie restriction can increase the lifespan by reducing inflammation and other factors risk of chronic disease, but with mixed results as to whether it has a negative or no effect on immune cell-mediated responses, "said first and corresponding author Simin Nikbin Meydani, DVM, Ph.D., Human nutrition Director Jean Mayer USDA Research Center on aging at Tufts (HNRCA) and the director of the nutritional immunology laboratory. "This study is the first to examine the effects of two years on healthy individuals, Normal- or slightly over-weight and observed that caloric restriction reduces inflammation without compromising other key functions of the immune system such as antibody production in response to vaccine. "
Chronic inflammation has been shown to create succession 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), seven of the 10 leading causes of death in 2010 were chronic disease, heart disease and cancer represents almost 48 percent of all deaths. The CDC also reports that year 86 percent of all health spending was for people with one or more chronic conditions.
After six weeks of basic tests, which included metabolic measurements to determine total spending daily energy and blood collection to assess inflammation and markers of cell-mediated immunity, 220 eligible individuals were randomized into two groups and further stratified by site, sex, and body mass index.
the control group maintained their normal diet for the duration of the study, while the test group was provided with the support to maintain a diet high in satiety limiting calories 25 percent, including personalized behavioral counseling. The test group was also given multivitamins and minerals to prevent micronutrient deficiencies. To maintain a 25 percent calorie calorie requirements of the test group was reduced to three times through the two-year study to coincide with their weight loss on the basis of body fat, and calculations muscle mass.
inflammation and immunity biomarkers were measured at baseline, 12 months and 24 months. Vaccine response was determined at the end of the study. As an indicator of susceptibility to infectious diseases, cell-mediated immunity was measured as the antibody response to three vaccines and skin tests, white blood cells in the blood, and self-reported disease. Furthermore, the inflammation was controlled using common levels of inflammatory markers including C-reactive protein, TNF alpha, and the serum leptin.
The research team found that the test group had a significant and persistent reduction in inflammatory markers with no discernible difference in immune responses in the control group at the end of 24 months. However, while reducing weight, body fat, and leptin levels were most pronounced at 12 months, they are not accompanied by a significant reduction in C-reactive protein and TNF alpha, both indicators of inflammation, up to 24 months. This delay suggests that long-term calorie restriction, at least 24 months, induces other mechanisms that may play a role in reducing inflammation.
"This may be one of the non-genetic response most powerful to slow aging, increase the duration of our health and the quality of our lives," added Meydani of HRNCA. It is also a professor at the Friedman School of Nutrition Science and Policy, School of Medicine at Tufts University, and a faculty member of the immunology program at the Sackler School of Graduate Studies of Science biomedical at Tufts.
"These changes limited calories suggest a change towards a healthy phenotype given the established role of inflammation in the development of cardiovascular disease, cancer and aging. With all of today's fitness and biometric measurement technology available to the public, it is certainly possible for the average person to maintain a 10-15 percent calorie restriction as a strategy for long-term health benefits, "said co-author Luigi Fontana, MD, Ph.D., professor of medicine and nutrition at Washington University in St. Louis and the University of Brescia (Italy).
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