Not all fish oil supplements pass muster, Consumer Reports says

In a Consumer Reports test of fish oil supplements, most passed muster but some didn’t measure up on quality.

Lab test results on 15 top brands analyzed for amounts of omega-3 fatty acids, disintegration, spoilage and contaminants. Researchers found that at least one sample from six brands didn’t meet all the standards set. The results were released Tuesday and are available on newsstands.

Over-the-counter fish oil supplements are extremely popular and used to treat heart disease, high blood pressure and psoriasis and a number of other ailments.

All the tested supplements had the amount of EPA and DHA omega-3 fatty acids listed on the label, and none went over the limit of lead, dioxins, mercury or PCBs (polychlorinated biphenyl, considered an organic pollutant), according to maximums set by U.S. Pharmacopeia, a nonprofit organization that determines quality and purity standards for medicines, food ingredients, and dietary supplements.

However, samples in four brands (CVS, GNC, Sundown and Nature’s Bounty) had total PCBs that might earn a warning label under California’s Proposition 65, the Safe Drinking Water and Toxic Enforcement Act. Two Costco brands failed the U.S. Pharmacopeia test for disintegration in capsules that had an enteric coating, meant to reduce the fishy aftertaste some supplements have.

In brands that passed Consumer Reports’ tests, most contaminants were found in measurable levels, but those levels were not high enough to be a cause for concern, even though some labels stated the products were free of toxins.

“Fish oil is not a cure-all,” said Health and Family editorial director Ronni Sandroff in a news release. “If you’re considering a fish oil supplement, we recommend that you talk to your doctor first to find out if it’s the right treatment for you. In our recent tests, we found that some were not as pure as one might think.”