Omega 3 fatty acids

The case for fish oil dates back more than 20 years, when studies showed relatively few heart problems among Japanese who ate a lot of seafood. Similar benefits were later found among Greenland Eskimos, and after two decades of follow-up, a study last year in the New England Journal of Medicine reported that Dutch men who eat at least one ounce of fish a day have only half the rate of coronary disease of those who eat no fish. The benefits apparently are due to the relatively large amounts of a fatty acid called omega 3 in fish. Biochemically speaking, omega 3 and omega 6 fatty acids occur side by side in the body. When enough omega 3 is present, scientists believe, it can dampen the tendency of omega 6 acids to overreact and produce too many eicosanoids—substances implicated in, among other things, inflammation and thrombosis. In studies at the Oregon Health Sciences University, diets high in omega-3 reduced cholesterol and triglycerides, another fatty substance in the blood
linked to coronary disease. Research the omega-3 elsewhere has shown that it protects against heart disease. By reducing the capacity of thromboxane (a potent platelet-clumping agent) to clot blood and constrict vessels, omega-3 reduces the risk of coronary occlusion. No one knows how much fish oil is desirable or, for that matter, whether an excess might do more harm than good. Researchers close to the field, however, see virtue in meals containing fish two or three times a week. One of the scientists, Dr. William E. Lands, a professor of biological chemistry at the University of Illinois, suspects that overproduction of eicosanoids—a word he says the public will be hearing more of— probably plays a role in an array of other disorders, including headaches, strokes, rheumatoid arthritis, asthma and perhaps the spread of cancer cells. Fish are not equal in their production of omega-3. One of the most prolific is the Chinook salmon, containing about 3.6 grams in a four-ounce serving. The sockeye salmon has about 2.3, followed by the albacore tuna (2.6), mackerel (1.8 to 2.6) and herring (1.2 to 2.7). But omega-3 is present in less concentration in rainbow trout (1), whiting (0.9), king crab (0.6), shrimp (0.5) arid cod (0.3).

omega-3