Fish oil capsules pack same omega-3 punch as fish

By Anne Harding

NEW YORK (Reuters Health) - Fish oil capsules and fatty fish do an equally good job of enriching the blood and other body tissues with healthy omega-3 fatty acids, new findings suggest.

But the findings can't be interpreted to mean that capsules and fish are equally good for the heart, Dr. William S. Harris, who was involved in the research, told Reuters Health. "There are things that can change the blood lipids but don't do anything for the heart and vice versa," said Harris, who is with the University of South Dakota in Sioux Falls.

Omega-3 fatty acid consumption is recommended by the American Heart Association and several other groups to reduce the risk of cardiovascular disease and consumption of fatty fish and fish oil capsules have been assumed to have similar effects, Harris and his colleagues note in the American Journal of Clinical Nutrition.

But there has been little research on whether the body processes fatty acids from fish oil capsules and fish in the same way.

To investigate, Harris and his team had 11 women eat two servings of tuna or salmon each week, while an additional 12 women took in the same amount of omega-3s, an estimated 485 milligrams daily, in capsule form.

After 16 weeks, the amount of omega-3 fatty acids in the red blood cells of women in both groups had risen by 40 percent to 50 percent, while omega-3s in the plasma (the cell-free, liquid portion of the blood) had risen by 60 percent to 80 percent.

"We went into the project assuming that fish would be better, based on some previous literature from other people," Harris noted in an interview. Based on the current findings, he added, "it doesn't make any difference whether you get your omega 3 fatty acids from a concentrate in a capsule or in fish -- they have the same effect on enriching the tissues with omega 3."

Nevertheless, Harris said, he would encourage people to eat fish rather than relying on fish oil capsules. "Fish of course brings with it proteins and minerals and other factors that are good for our health that the capsules don't bring, but we weren't able to measure any of those things," he said.

SOURCE: American Journal of Clinical Nutrition, December 2007.