February 4, 2004 NUTRITION NEWS FOCUS "Nutrition news is important. We help you understand it!" Today's Topic: Unsaturated Fat and Your Blood Vessels Most of us know that consuming unsaturated fat is supposed to lower serum cholesterol and keep our arteries unclogged. However, a few studies have found the opposite; higher polyunsaturated fat intake was correlated with more heart disease. A new study attempts to explain this by reporting that a gene controlling metabolism of unsaturated fat puts people at risk. The gene codes for an enzyme called 5-lipoxygenase and is involved in metabolizing polyunsaturated fat to hormone-like chemicals called leukotrienes. Each person has two genes for this enzyme. In a study of 470 people in Los Angeles, one in 15 had variants of the common genes. Having two variant genes was associated with significantly more atherosclerosis of the carotid artery in the neck that supplies blood to the brain. There were marked differences by ethnicity in the results. The variant genes were six time more common in blacks than in whites, with Asians also having a high prevalence. The study was published in the January 1, 2004 edition of the New England Journal of Medicine. < http://content.nejm.org/cgi/content/abstract/350/1/29 > HERE'S WHAT YOU NEED TO KNOW: Although polyunsaturated fat lowers cholesterol in most people, the effect seen here was not mediated through serum lipids but probably through effects on inflammation. Arterial disease is becoming more accepted as a chronic inflammatory condition rather than a problem with cholesterol only. Intake of omega-3 fatty acids, primarily from fish, blunted the effect of the other polyunsaturated fats on promoting arterial disease.