Pregnant Women Warned To Avoid Tuna

It’s a lunchtime staple for many people, but some experts are warning women and young children to limit the amount of tuna they’re eating or to cut it out of their diet altogether.

While fish are a great source of high-quality protein and omega-3 fatty acids, thanks to industrial pollution some aquatic creatures contain mercury, which can be harmful to an unborn child.

Consumer Reports has advised women of childbearing age, nursing mothers and children to avoid canned tuna.

“What we did is looked at the individual samples and what we found is that the levels of mercury varied widely among the cans that we saw,” Urvashi Rangan, a senior scientist for Consumer Reports, explained.

The research was done in the United States, but the findings still apply in Canada.

Canned light tuna is often recommended as the safer choice because it’s said to have a lower mercury content than albacore, but Consumer Reports researchers say that’s not always the case.

The group based its study on U.S. Food and Drug Administration information that says light tuna has much less mercury than albacore.

For the most part, C.R. said that’s true, but the high levels of mercury in six percent of light tuna samples – sometimes twice that of albacore – were a cause for concern.

“We felt like you can’t know what you’re going to get in any given can of tuna that you buy,” Rangan said.

Mercury can have serious effects on a developing nervous system.

“There have been reports of incidents of a cerebral palsy-type condition with retardation, blindness and trouble with reflexes and nerves,” Fay Weisberg, a fertility specialist at Sunnybrook and Women’s College Health Sciences Centre, said.

The U.S. Tuna Foundation claims the mercury levels are “well below government standards” and questioned Consumer Reports’ research methods.

Health Canada set a guideline of 0.5 parts per million (ppm) for mercury in commercial fish.

Shark, swordfish, fresh and frozen tuna exceed that level and Health Canada says you should limit your consumption of these products and women of childbearing age shouldn’t eat more than one serving per month.

Here’s a list of tuna alternatives (Courtesy of Consumer Reports):

Clams, oysters, pickerel, shrimp, Whiting: undetectable mercury ppm

Fresh or frozen salmon, tilapia: 0.01 ppm

Sardines: 0.02 ppm

Freshwater trout: 0.03 ppm

Anchovies: 0.04 ppm

Catfish, flounder, mullet, scallops, sole: 0.05 ppm

Blue, king, snow crab, Pollock: 0.06 ppm

American shad, squid, whitefish: 0.07 ppm

For more information on mercury levels in Canadian fish, click here.