The cells which line the inside of blood vessels are called endothelial cells and are vital for proper functioning of blood vessels. They control the ability of the vessel to contract and dilate, which in turn controls blood flow through them. Damage to the inner lining can lead to the vessels not functioning properly and eventually high blood pressure and blood vessel disease.
Increased body fat has been linked to both early heart disease and endothelial dysfunction. To determine the impact of fat gain and its distribution on endothelial function in lean healthy humans, researchers from Sweden randomly assigned 43 normal-weight adults to either gain about nine pounds (4kgs) or keep their current weight. The researchers measured endothelial function in the brachial artery, which is present in the arm. Specifically, they looked for the ability of the artery to widen. Measurements were taken before the study started, after 8 weeks of weight gain and again after 16 weeks of weight loss.
People who gained weight showed a decrease in the ability of the artery to widen. However when they shed the weight again, the ability of the brachial artery to widen properly came back to normal. This study shows that weight gain, especially increase in abdominal fat is directly linked to impaired functioning of blood vessels. This study provides yet another reason to maintain a healthy weight and avoid excess belly fat. [Reference: Journal of the American college of Cardiology, August 2010]