Fish can be part of a healthy diet and is rich in omega-3 fatty acids, which benefit heart and cardiovascular health. But there is also a downside, as many kinds of fish have been showing up with high levels of mercury due to swimming in contaminated waters. Mercury is a heavy metal that can cause toxic effects in the body in high enough doses (www.winkipedia.com). This is of great concern to mothers who would like to get their kids to eat more fish, including tuna.
Nearly all fish and shellfish contain some level of mercury. People especially at risk from mercury include pregnant women, women of childbearing age who may become pregnant, unborn babies and small children. If a pregnant mother ingests too much mercury, she may put her fetus at risk for damage to the developing nervous system. It is recommended that these higher risk groups avoid eating any shark, swordfish, King mackerel or Tilefish because they contain the highest mercury levels.
While light canned tuna, shrimp, salmon, pollock and catfish tend to have less mercury that the above mentioned fish varieties, it is still recommended to limit your intake. With tuna, stick to the light varieties, and avoid Albacore because it tends to be higher in mercury. The Food and Drug Administration suggests that up to 12 ounces per week is safe, and with Albacore, 6 ounces per week or less. My personal recommendation would be to keep it lower for small children and skip the Albacore type altogether.( See http://water.epa.gov/scitech/swguidance/fishshellfish/outreach/advice_index.cfm for more information .)
Mercury accumulates in the body and can contribute to learning and hearing problems, and other conditions. From all of the information I gathered for this article, the general consensus from the Environmental Protection Agency and the FDA seems to be to avoid the fish containing the highest mercury levels, to stick to light tuna as opposed to white (Albacore) and to limit the intake to up to 12 ounces per week. It’s a shame that such a wonderful, healthy part of the diet now has to be a concern for other serious health reasons. Follow these guidelines to still enjoy fish, while minimizing your chances for too much mercury exposure.