Omega-3 fatty acids are essential for good health, but they cannot be made by the cells of the body. You must get them from sources such as fish, nuts, soy, canola oil and tofu. They lower triglyceride levels and blood pressure, prevent atherosclerotic heart disease and are possibly a treatment for rheumatoid arthritis.
What is Omega 3?
Eicosapentaenoic acid, or EPA, docosahexaenoic acid, or DHA, and alpha linolenic acid, also called ALA, are all commonly referred to as the omega-3 fatty acids. They are also called the essential fatty acids because they are absolutely necessary for good health and yet, the cells of the body cannot make them, as explained by Kathleen Botham, Ph.D., Professor of Biochemistry at the University of London in "Harper's Illustrated Biochemistry." You must get these fatty acids from your food.
Why Omega-3?
People get DHA and EPA from eating fish like tuna, sardines or salmon. Eating soy, nuts, canola oil and tofu provides ALA. Scientists first thought omega-3 from fish might be healthy when they looked at the diet of Alaskan and Greenland Inuits, according to Mitchell Krucoff, M.D., Professor of Medicine and Cardiology at Duke University Medical Center in "Hurst's The Heart." The Inuit diet was high in fat, but most of it was omega-3 fatty acids from eating whale and seal. The Inuit people had fewer cases of coronary artery disease when compared to other populations.
Studies About Omega-3
In "Hurst's The Heart," Dr. Krucoff writes about several studies involving omega-3 fatty acids. In three studies, people who ate some fish every week had a lower death rate from coronary artery disease. Forty studies showed that omega-3 fatty acids protected against heart disease, while still others concluded that they slowed atherosclerosis, or the hardening and narrowing of the arteries from plaques filled with cholesterol. An Italian study of 5,666 people who took omega-3 after a heart attack had a 45 percent decrease in sudden death.
Current Claims
The current medical evidence is that 800 to 1,500mg of omega-3 every day lowers the risk of having a heart attack or dying for those who have coronary artery disease and are taking medication, writes Ara DerMarderosian, Ph.D., Scientific Director of the Complementary and Alternative Medical Institute in "The Merck Manual for Healthcare Professionals." Having 4g every day lowers the triglyceride levels by 25 to 40 percent, while having at least 3g a day lowers the blood pressure by 2 to 4mm/Hg. Physicians hypothesize that omega-3 is beneficial in preventing atherosclerotic heart disease and kidney damage from cyclosporine, and in treating rheumatoid arthritis.
Toxicity
Some people who take omega-3 fatty acid supplements may develop nausea, diarrhea and belching, notes DerMarderosian. Taking more than 3g every day increases the risk of bleeding. In addition, some have expressed concerns about mercury contaminating the fish supply. According to DerMarderosian, even though lab testing does not show this contamination, neither pregnant women nor women who are breast-feeding should take fish oil supplements. They should also limit eating fish with higher mercury levels, like mackerel.
References
- "Harper's Illustrated Biochemistry"; Robert Murray, M.D., Ph.D., David Bender, Ph.D., Kathleen Botham, Ph.D. et al.; 2009
- "Hurst's The Heart"; Valentin Fuster, M.D., Ph.D., Robert O'Rourke, M.D., Philip Poole-Wilson, M.D., Richard Walsh, M.D.; 2008
- The Merck Manual for Healthcare Professionals: Fish Oil
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