Written by Patrick Massey M.D., Ph.D.  A research study has shown that fish oil improves heart function in healthy people.

Some fish migrate thousands of miles each year. The secret to their marathon abilities could be that fish oil makes the heart stronger.

Recent medical research has shown that it also works for human hearts. In one study, researchers demonstrated that healthy hearts can work better with two important fish oils, docosahexanoic acid (DHA) and eicosapentaenoic acid ( EPA).

DHA and EPA are often referred to as omega-3 fats. Over the past 20 years, a large body of research has demonstrated that these specific omega-3 fats benefit every organ system in the body, from the brain to the skin. Humans cannot make these omega-3 fats easily and so we need to get them in our diet, either by eating fish or taking fish oil supplements.

As important as these oils are in their treatment and prevention of disease, there is still some question about the benefit in healthy people. Can healthy people become even healthier by taking omega-3 fats?

According to one research study, the answer is yes. A recent study, done at the University of California-Davis, looked at the benefits of DHA and EPA on the healthy heart. This study examined the effects of these omega-3 oils on several parameters of heart function at rest and during work including blood pressure, cardiac output (how much blood the heart can pump over time), stroke volume (the total amount of blood pumped with each contraction) and heart rate. Twelve participants received generous, daily amounts of both EPA and DHA while, as a control, nine participants received safflower oil.

The safflower oil group had no changes in their heart functions, whereas the EPA/DHA group showed significant improvements in several of the tests. There were improvements in cardiac output, stroke volume and one of the tests for blood pressure. This indicated that consuming EPA and DHA significantly improved oxygen delivery to the body during exercise. This research has important implications for those who are healthy as well as those who are not.

If fish oil can improve heart function in healthy people, it may have an even more robust result in those who are sick and debilitated. One can imagine the potential benefits to patients undergoing cardiac rehabilitation. There may also be implications for healthy people in preventing heart disease and maintaining lifelong vitality.

The doses of EPA and DHA used in the University of California study were higher than what is usually recommended. Participants consumed 2 grams of DHA and 3 grams of EPA per day. Most current recommendations are much lower. However, the study was only six weeks and a higher dose may have been necessary to see improvement over a short period of time. Lower doses, over a lifetime, may be just as effective.

Overall, American fish oil is safe. According to Consumer Labs, it is free from mercury and other toxins. However, those on the blood thinner Coumadin need to be cautious. In rare cases, fish oil may thin the blood more. As always, check with your doctor before taking supplements.

Posted November 19, 2008.