But there could be another culprit: concerns about mercury. This naturally-occurring mineral can be toxic in high levels, and it tends to hang around in your body, so pros recommend limiting consumption of fish that contain a lot of it. Pregnant or breastfeeding women are warned to watch their intake because high levels of mercury can damage the developing brain and nervous system of a fetus or baby, but small children and any woman of childbearing age should be concerned as well.
Related: The 5 Fish That Are Most Contaminated—And What To Eat Instead
Still, Gans says, avoiding seafood all together is a bit extreme—and unnecessary. “There are way more fish that are low in mercury than high in mercury,” she says, such as salmon, flounder, lobster, and cod. (Check out this list of low-mercury fish from the FDA to see the full range of options). Big-game fish such as swordfish, bigeye tuna, marlin, orange roughy, shark, and king mackerel tend to have the most mercury, since they eat other mercury-containing fish.
Plus, the mercury risk of fish may be a little overhyped. A 2013 study found that seafood accounted for only 7 percent of the mercury in women's bodies. And dietary recommendations seem to be changing, too. The FDA and EPA actually recommend that pregnant women eat more cooked seafood to reap the nutritional benefits found in fish for their developing child. The benefits seem to outweigh the risks.
Bottom line: We could all stand to eat more seafood, says Gans. "I suppose you could eat fish every day as long as your choices are low in mercury," she says, although she recommends a "varied diet" to get a wide range of nutrients. Gans says she follows the American Heart Association's guidelines of at least two 3.5-ounce servings a week. (For higher-mercury fish, such as canned tuna, you can have maximum one serving a week, per FDA recommendations). If you're pregnant, stick with the FDA's recommendation of two to three servings of low-mercury fish per week to reap those important developmental benefits.
The article How Much Fish Is It Safe To Eat Per Week? originally appeared on Women’s Health.