Two months ago, a study was released showing farmed salmon contained higher levels of pollutants -- pesticides and PCBs -- than wild salmon. Following up on that study, CTV News has looked into the contaminants of fish oil capsules, which are touted as a healthy alternative.

Health Canada urges us to eat a gram a day of fish to get the benefits of the fish oils rich in nutrients called omega 3 fatty acids that seem to protect against a number of diseases.

Yet, after the study on toxins in farmed salmon, some scientists recommended consumers in North America consider eating farmed salmon just once a month.

Some suggested fish oil capsules as a healthy alternative. But the question remained -- how do contaminants in fish oil capsules compare to those found in the fish themselves?

CTV commissioned a study of its own, to measure the contaminants found in fish capsules from dozen manufacturers.

The results were surprising. Not only do the capsules contain the beneficial fatty acids in high concentrations, but they are also cleaner than the fish they came from.

According to the companies' own laboratory results, all the capsules tested contained well below one nanogram per gram of PCBs. That means a person would need to take more than 300 fish oil capsules to be exposed to the amount of PCBs in a single serving of farmed salmon.

Even a relatively toxin-free wild fish has the same PCB content as about 20 capsules.

And on the plus side, fish oil capsules contain about 30 times the amount of the key omega-3s as a single fish meal.

For Robert Orr, president of fish oil manufacturer Ocean Nutrition, the findings weren't surprising. Orr told CTV News that most capsule makers use smaller fish that have not accumulated as many contaminants as the bigger fish sold in fishmongers and grocery stores.

And, he explained, manufacturers like his actually clean the oil in a process called "molecular distillation."

"It strips most of the man-made pollutants that may be in the oil," he said, explaining the omega 3s are left behind, in potent doses.

For Dr. Tom Barnard, it all adds up to make taking the fish capsules a no-brainer.

"It's cheap and it's non toxic if you take a couple of fish oil [capsules] a day," he told CTV. "It's cheap nutrition insurance."

In 2003, sales of fish oil capsules jumped 58 per cent.

Health Canada recommends Canadians consume 1.4 grams of omega 3s daily -- the equivalent of two servings of dark, fatty fish a week, or approximately 1.5 capsules every day.

Published research has shown that fish oil can be used to treat a variety of conditions including asthma, arthritis, and colitis, as well as lupus, cystic fibrosis and schizophrenia. Consumption of omega 3s has also been credited with lowering the risk of suffering a heart attack or developing cardiovascular disease.

But buying the capsules isn't cheap, and some argue that consumers who choose pills are missing out on the other essential nutrients found in fresh fish, like selenium and vitamin D.

Laval University's Dr. Eric Dewailly is one who says skipping the fish might mean missing out on all the benefits.

"Remember the studies have been done on fish eaters, not oil eaters," he said. "So don't take a chance. Eat the fish."

Since studies have only proved an association, and not a direct correlation between fish oil and its purported health benefits, those looking for a panacea may be disappointed.

But as more studies emerge linking toxins in seafood to diseases in the people who eat, those who see little downside to boosting their omega 3s intake can at least feel they have little to lose by choosing a cleaner source of the beneficial fatty acids.

The tests, commissioned by The Globe and Mail and CTV were conducted by two independent laboratories -- Ontario-based NutraSource Diagnostics and B.C.-based AXYS Analytical Services Ltd.

AXYS is the same lab that tested PCB levels in farmed salmon for the report published last month warning consumers to limit the amount of farmed salmon in their diet.