Fish oil gets lots of hype – and support from clinical science

PHILADELPHIA – Americans love their fish oil – and so do many of their doctors, which makes this “natural” remedy different from most others.

That’s because it has something other healing products in the marketplace lack: Science behind its health claims.

Studies show that the omega-3 fatty acids in fish oil can reduce heart-attack risk by preventing blood clots and abnormal heart rhythms, which cause sudden death.

OK, so it tastes a little fishy and sometimes causes burping or diarrhea. And because of its apparent blood-thinning effects, it’s not a good fit for patients on prescription blood thinners or headed into surgery.

But for people concerned about their heart health, and for the doctors who treat them, fish oil may be a great catch.

“There’s definitely a lot of hype, but also some good clinical science behind it, too. I certainly prescribe fish oil a lot,” said Daniel J. Rader, director of the Preventive Cardiovascular Medicine and Lipid Clinic for the University of Pennsylvania Health System.

Sales of fish oil supplements in the United States have climbed accordingly, from $35 million in 1995 to an estimated $310 million this year, according to the Nutrition Business Journal, which tracks the dietary supplement industry.

Fish oil’s heart-healthy potential came to light in the early 1970s, when Danish investigators noted that despite the high-fat diet of the Greenland Inuit, they rarely experienced heart attacks. The Inuit diet was replete with cold-water fish containing omega-3s.

Since then, the benefits of omega-3s have been studied for their role in stabilizing heart-muscle cells, thus reducing the likelihood of arrhythmia; in fighting inflammation, and making arteries more elastic.

A small study reported in the June issue of the Journal of the American Medical Association, however, raised questions about fish oil’s ability to prevent irregular heart rhythms in certain high-risk cardiac patients.

Fatty fish such as salmon, albacore tuna, bluefish, mackerel, lake trout, herring and sardines are especially good sources for the helpful omega-3s: EPA, or eicosapentaenoic acid, and DHA, or docosahexaenoic acid.

The body can make both of them from another fatty acid, alpha-linolenic acid (ALA) – found in flaxseed, canola, olive, soy and walnut oils – but only to a limited extent.

Fish oil has been shown to have beneficial effects on cholesterol, lowering the “bad” and raising the “good,” possibly thinning the blood and reducing blood pressure. High cholesterol and blood pressure are key risk factors for atherosclerosis, or clogged arteries, which is the major cause of heart disease.

According to the National Institutes of Health, more than 1 million people in the United States have a heart attack and 515,000 die each year, usually from arrhythmias.