Even modest weight loss reverses many of the damaging changes often seen in the immune cells of obese people, particularly those with Type 2 diabetes, according to scientists at Garvan Institute of Medical Research, Sydney, Australia. It has been known for some time that excess body fat, particularly abdominal fat, triggers the production of “pro-inflammatory” immune cells, which circulate in the blood and can damage the body. Further, other inflammatory immune cells (macrophages) are also activated within fat tissue. The recent study looked at obese people with Type 2 diabetes or prediabetes with a diet limited to 1,000 to 1,600 calories a day for 24 weeks. Gastric banding was performed at 12 weeks to help further restrict food intake. The study determined the effects of weight loss on immune cells, finding that there was an 80% reduction of pro-inflammatory T-helper cells, as well as reduced activation of other circulating immune cells (T cells, monocytes and neutrophils) and decreased activation of macrophages in fat. These findings are published in the Journal of Clinical Endocrinology Metaboism, now online.
Excess weight disorders now affect 50% of adult Australians. Obesity is the major cause of Type 2 diabetes and some cancers, said associate professor of the Institute Katherine Samaras. “The situation has reached crisis point….We have found that a modest weight loss of about 6 kg is enough to bring the pro-inflammatory nature of circulating immune cells back to that found in lean people. These inflammatory cells are involved in promoting coronary artery disease and other illnesses associated with obesity. This is the first time it has been shown that modest weight reduction reverses some of the very adverse inflammatory changes we see in obese people with diabetes. We also showed that the activation status of immune cells found in fat predicted how much weight people would lose following a calorie restricted diet and bariatric surgery. Those with more activated immune cells lost less weight. It’s the first time this has been described and is important because it helps us understand why some people lose weight more easily than others, and that inflammation is involved in regulating the response to bariatric surgery.” People must be made aware that excess fat will affect their immune systems, thus their survival.