Being overweight is something all doctors and most laypeople know significantly increases the risk of acquiring type 2 diabetes. In fact, the American Diabetes Association (ADA) says that more than 90 percent of people who are newly diagnosed with type 2 are overweight. But why does excess fat increase the risk of diabetes? Isn’t the disease, after all, one that involves the body’s inability to metabolize glucose?
Well, researchers at Emory University in Atlanta think they may know why fat can be a culprit in acquisition of the disease. In a study published in February in the Journal of Endocrinology and Metabolism, a team led by Guillermo E. Umpierrez, MD, a professor of medicine at Emory University School of Medicine, concluded that free fatty acids “are leading candidates in the development of insulin resistance and hypertension in obese patients.”
At sustained levels, fatty acids, which are cells that move freely through the bloodstream, are implicated in increased blood pressure and cardiovascular inflammation, interference with endothelial function,* and negative effects on the hormonal system that affect body’s fluid balance.
The Emory researchers also found that fatty acids inhibit insulin’s ability to dispose of glucose in peripheral tissues, increasing the body’s intolerance of carbohydrates-a precondition of type 2 diabetes.
To reach their conclusions about fatty acids, the team studied the effects of lipid injections on a group of 24 African-American patients with type 2 diabetes. The patients had normal blood pressure and an average body mass index of 37. Random members of the group received Intralipid/heparin (Intralipid is the brand name for a fat emulsion) over a 48-hour period, while the others received a placebo saline/heparin solution.
Within four hours, blood pressure in the lipid infusion group had increased significantly. The increase was sustained, and there was also an increase in their markers for cardiovascular inflammation and endothelial dysfunction.
An interesting sidebar to Dr. Umpierrez’s study is his current investigation of olive oil as a nutrient for critically ill hospital patients who must receive nutrition by injection. Because olive oil is a mono-unsaturated fatty acid, he thinks it may cause less inflammation and endothelial dysfunction than the fatty acids hospitals currently administer to such patients.
* The endothelium is a thin layer of cells that lines the entire circulatory system and acts in several significant ways, including controlling blood pressure; controlling the exit from and entrance into the bloodstream of white blood cells; and the formation of new blood vessels.