If you're pregnant (or trying, or even thinking about trying) making fish a regular part of your diet has always been considered a good move health-wise. After all, both fresh and saltwater fish are considered an excellent source of protein. And many species are packed with disease-fighting and brain-boosting compounds that benefit you and your baby-to-be.
But now there seems to be a catch when it comes to eating fish: Both the Food and Drug Administration and the U.S. Environmental Protection Agency warn that certain types of fish contain dangerously high levels of a poison called methyl mercury. When methyl mercury builds up in the body it can damage the brain and nervous system. Toxic levels can affect your vision and motor-ability. In an unborn baby, exposure to high levels can affect brain development. "What we've found is that methyl-mercury interferes with the formation of myelin. Myelin is a fatty-like substance that insulates the nerve endings in the brain," explains Kathy Mahaffey, Ph.D., director of the division of exposure assessment for the EPA.
One of the biggest sources of methyl mercury comes from industrial pollution that is first released into the air, and then settles into both fresh- and salt-water sources. The EPA is hoping efforts to reduce environmental sources of mercury will eventually reduce levels of toxicity. But they say it will be years before we see any major improvements.
In the meantime, the EPA has issued the following advisories:
- Women who are pregnant or could become pregnant; nursing mothers (and young children) should not eat shark, swordfish, king mackerel, or tilefish.
- Women of childbearing age and pregnant women may eat an average of 12 ounces of any other fish each week. This includes fish purchased in stores, ordered at restaurants, as well as fish caught by you or a family member or friend.
From the moment of conception, you and your baby need a well-balanced diet. Make sure you know: