Australian scientists have shown for the first time that 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.
The immune system is made up of many different kinds of cells that protect the body from germs, viruses and other invaders. These cells need to co-exist in a certain balance for good health to be maintained. Many factors, including diet and excess body fat, can tip this balance, creating cells that can attack, rather than protect, our bodies.
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 our bodies. In addition, other inflammatory immune cells, known as macrophages, are also activated within fat tissue.
The recent study looked at 13 obese people with Type 2 diabetes or prediabetes who were limited to a diet of between 1000 and 1600 calories a day for 24 weeks. Gastric banding was performed at 12 weeks to help restrict food intake further. The study determined the effects of weight loss on immune cells
Undertaken by Dr Alex Viardot and Associate Professor Katherine Samaras from Sydney's Garvan Institute of Medical Research, the results showed 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. They are published in the prestigious Journal of Clinical Endocrinology Metabolism, now online.
"Excess weight disorders now affect 50% of adult Australians, with obesity being the major cause of Type 2 diabetes and some cancers," said Associate Professor Samaras.
"The situation has reached crisis point, and people must be made aware that excess fat will affect their immune systems and therefore their survival."