Byline: Kent Sepkowitz
Fish oil's slippery health claims.
For the past 10 years, I've started my morning with a handful of fish-oil gel caps. Like many, I hoped this simple step would help prevent the most common diseases of modernity--heart attacks and strokes. So my day was darkened by a recent article in the Journal of the American Medical Association that reviewed the fish-oil evidence and found no demonstrable benefit.
My reasoning had been relatively sound. The fish story started in the 1970s, when small observations about fish-based diets suggested that eating more fish meant a longer life. With this lead, clinical trials were organized and patients enrolled. The problem of normalizing fish consumption was solved by a process called wet pressing, whereby large amounts of fish are cooked, pressed, and centrifuged to remove the oil, which is put into a soft gel capsule. Most of the studies have relied on this product rather than on counting pieces of actual salmon eaten. The science hinged on the observation that omega-3 fatty acids have a calming effect on platelets, those sticky components of blood that can block the circulation.
In the popular imagination, fish oil swiftly took its place as a cure-all, like its quasi-antecedent, cod-liver oil. True believers claim omega-3s can not only reduce heart attacks and strokes but also prevent cancer, sharpen memory--even ameliorate attention-deficit problems. …