You've probably heard about fish oil in the last six months. You'll hear a lot more in the future. There is evidence that the small amounts of fish oil you get from eating fish can significantly reduce the risk of heart attack. Higher dosages of fish oil can be administered to reduce high blood levels of triglycerides, the most common type of fat we get from foods.

Fish oil -- or, to be specific, the long-chained fatty acid called EPA -- has been the focus of several studies reported in scientific journals and the press:
First, a study of Eskimos living in Greenland showed they have a much lower rate of heart attacks than people in other societies who eat comparable amounts of fat. The significant differences that most of the fat in Eskimos' diet comes from fish rather than from meat and vegetable oils.

Dr. Scott Grundy, director of the Center for Human Nutrition, says that the unique quality of EPA seems to be its ability to prevent the rapid collection of blood platelets at the site of atherosclerotic plaques. When blood platelets collect, a blood clot forms and coronary thrombosis or heart attack, results.

A study done at the University of Oregon showed a remarkable decline in the blood triglyceride levels of patients with a genetic inability to metabolize fat. Three diets were tested on each patient. One was high in fish oil, mostly from salmon. The second used comparable amounts of safflower and corn oil. The third was a very lowfat diet, typical of the diet usually fed such patients.

The diet high in EPA from fish oil lowered triglyceride levels of these problems patients by 64% to 79%. Cholesterol levels also fell. Therapeutic amounts of fish oil are now being prescribed for this problem.

The results of a 20-year study in Holland also were reported recently. A group of men who ate as little as one ounce of fish a day, the equivalent of two or three fish meals a week, had 50% fewer heart attacks than others who did not eat fish.

Grundy recommends eating two fish meals a week to aid in the prevention of heart disease. He explains that EPA, the beneficial fish oil, is found in the flesh of certain deep water fish. It is not in the oil in the liver, such as cod liver oil. Some good sources are bonito, herring, mackerel, pompano, salmon, whitefish, shad, albacore, chinook and trout. These deep-water fish have access to plankton, which is rich in EPA.

These studies have naturally stirred interest -- ranging from speculation to extreme enthusiasm -- among people interested in nutrition. Grundy was a member of a group convened by the Department of commerce's National Marine Fisheries Service to evaluate the nutritional value of fish and fish oils in the prevention and treatment of coronary heart disease.

Their report concluded that fish oils appear to have dramatic potential value to health but that many important questions need to be answered before general recommendations can be made. Meanwhile, both basic research and clinical research into the effects of EPA are taking place in many medical centers. At UTHSCD several investigators are conducting EPA studies now or have research proposals out for funding.

Dr. Ricardo Uauy is an M.D./Ph.D. with appointments in both the Center for Human Nutrition and the Department of Pediatrics. His research involves infants who weigh less than three pounds at birth and who therefore lack the stores of essential polyunsaturated fatty acids that normal birth weight babies have. These fatty acids are considered important to mental and visual development.

Low birth weight babies are being tested on three formulas: one with fats similar to those provided by fish oil, one a more traditional formula using polyunsaturated fatty acids from corn oil and the third, breast milk. Uauy and his colleagues in pediatrics and pharmacology are measuring the fatty acid of membranes and plasma lipids and testing visual response. Their important study should be concluded by fall.

Dr. James Schmitz, assistant professor of internal medicine, is conducting research in conjunction with Grundy, cardiologist Dr. James Willerson and the physicians at the cardiac catherization centers at the Dallas Veterans Administration Medical Center and Parkland Memorial Hospital.

Patients who have undergone angioplasty, a process in which a balloonlike instrument is inserted into blocked arteries and inflated to widen the passage, are being given doses of EPA to see if it will prevent repeated blockage, which occurs in about one-third of patients.

Dr. Kathleen Zeller, who does research on kidney disease through the CHN and Dr. Philip Raskin's diabetes unit, has proposed research into the effects of EPA on the progression of kidney damage in diabetics.

Studies like these are necessary to prove the benefits of EPA in our diets.