We've heard countless times that eating fish is a great way to improve your health. But for some people it may do more harm than good. The warning is for pregnant or nursing women and for young children.
Toxocologists say some kinds of fish like fresh, frozen or canned tuna, swordfish, shark and others can contain Methylmercury from pollution.
This form of mercury gets bound in the fish tissue with the highest amounts being in shark and swordfish since they are higher up on the food chain.
It can be a concern in adults because it builds up in the body causing depression, hair loss, or headaches. Even though it isn't that common.
However, pregnant and nursing mothers can pass it on to their children who are much more susceptible. In children Methylmercury can cause permanent damage like learning disabilities and memory problems.
Toxicologists recommend one or two six-ounce cans at the most of tuna a week for women of childbearing age. But for those who are fish lover, salmon and sardines have less Methylmercury.
The FDA agreed to review its recommendations on fish consumption and mercury, especially after heavy criticism for what some called unacceptable and unhealthy standards for tuna.