The evidence was suggestive that mercury may have subtle effects on brain development for a child exposed in the womb, or in early childhood. To obtain the benefits of omega-3 fatty acids for brain development and minimize the potential risk of mercury, the investigators' findings agreed with the recommendations of the Environmental Protection Agency and Food and Drug Administration that women of childbearing age, nursing mothers and young children should eat up to two servings per week of a variety of fish (for example, salmon, light tuna, shrimp, mackerel, and up to 6 oz. per week of albacore tuna) and avoid only four species of fish--golden bass (also known as tilefish), king mackerel, shark and swordfish--larger, predatory fish that have higher levels of mercury. The researchers emphasized that this advisory is only for women of childbearing age, nursing mothers and young children, not the general population. Importantly, the evidence suggests that, for those women, it is as important for their health and for the brain development of their infants that they eat a variety of other types of fish as it is to avoid the four fish species higher in mercury.
Some studies have shown that PCBs and dioxins may be carcinogenic. The authors found that the benefits of eating fish far outweighed the potential cancer risks from these chemicals. "The levels of PCBs and dioxins in fish species are low, similar to other commonly consumed foods such as beef, chicken, pork, eggs, and butter. Importantly, the possible health risks of these low levels of PCBs and dioxins
Contact: Todd Datz
Harvard School of Public Health