There’s been a lot of conflicting information about fish consumption lately. As one visitor to our second trimester forum pointed out, we are being encouraged to add fish to our diet as a rich source of omega-3’s, but we’re also being told that those lovely fish fillets in the grocery store may be full of dangerous toxins like mercury and PCBs. So, should we be eating fish or not? Which ones are safe? Leslie Beck is a registered dietitian in private practice in Toronto and author of Leslie Beck’s Nutrition Guide to a Healthy Pregnancy. We asked her to set the record straight.
“When you’re pregnant, omega-3’s are extremely important, especially in the third trimester when your baby’s brain grows rapidly. One component of omega-3’s, called BHA, promotes baby brain growth, and the amount reaching the baby depends on mom’s diet. Fish is the best source of omega-3’s.
“However, some large fish contain dangerous levels of mercury, which can cause birth defects. Health Canada recommends that women who are planning to get pregnant or who are pregnant or breastfeeding limit their consumption of fish containing high levels of mercury to one meal a month.”
According to Beck, Health Canada is currently reviewing its recommendations. The US Food and Drug Administration has already told women of childbearing age to avoid high-mercury fish like fresh tuna, swordfish and mackerel (see “Which Fish are Safe?”) and to eat canned tuna only once a month.
But what about recent reports in the media that farmed salmon contain PCBs? Beck says there is no evidence that the trace levels detected add up to a serious health risk. “It is true that farmed salmon have higher levels of PCBs than wild salmon; however, the study that came out in January 2004 still showed that the average levels of PCBs in farmed salmon were far, far lower than the acceptable levels Health Canada tests for.”
• fresh tuna steaks
• tile fish
• king mackerel
• canned albacore tuna
• canned salmon (which is always wild)
• farmed trout (If you’re catching your own, check provincial lake advisories)
The bottom line? The health benefits of fish, especially during pregnancy, are just too important to eliminate them from your diet. Beck advises women to avoid or limit high-mercury fish to one 12-ounce meal a month, and eat a variety of other species.