High levels of antioxidant enzymes reduces the risk of heart disease

A meta-analysis conducted by Spanish researchers determined that higher levels of the body's antioxidant enzymes correlate with a lower risk of coronary heart disease. The bodys enzymes (Glutathione, SOD, and Catalase) defend against oxidative stress, which is characterized in atherosclerosis by the oxidation of lipids and proteins in the vascular wall, a process that is an initial step in the progression to heart disease. Oxidative stress is also involved in endothelial dysfunction (dysfunction of the cells lining blood vessel walls) leading to poor function of blood vessels.

For the analysis, Dr Maria-Isabel Covas, of the Cardiovascular Risk and Nutrition Research Group in Barcelona and her colleagues selected 42 case-control studies and 3 prospective studies that provided information concerning levels of the enzymes Superoxide Dismutase, Catalase and Glutathione Peroxidase, and coronary heart disease outcomes including fatal heart disease, nonfatal heart attack, or angina (chest pain). Pooled analysis of the data found a reduced risk of heart disease associated with higher levels of each enzyme compared with lower levels. The risk associated with a 1-standard-deviation increase (a measure of variance from average values) in Glutathione Peroxidase was 49% lower, while those associated with Superoxide Dismutase and Catalase were 52% and 68% lower. The study is published online ahead of print in the American Journal of Epidemiology.