Eat More Fish? Yes and No.

What New Federal Advice for More Fish in Diets of Children and Pregnant Women Means for Californians

Federal officials at the Food and Drug Administration and Environmental Protection Agency recently announced that they would recommend for the first time that women who are pregnant or breast-feeding and young children eat a minimum of two servings of low-mercury seafood every week for their health.

These recommendations suggest women only choose low-mercury seafood like salmon, shrimp, cod and tilapia and avoid top predators such as shark, swordfish and king mackerel, which accumulate mercury when they eat other fish.

This draft message has shifted from the previous federal 2004 advisory, which set a maximum amount of fish which are safe to eat by these groups, to avoid excessive exposure to contaminants such as mercury, but did not include a minimum recommendation.

This latest announcement is national advice specific to seafood, but what about fish caught from inland streams, rivers and lakes in California?  People in California need to be especially informed about which kind of fish they choose, because the history of mining and mercury use in the state has resulted in high levels of mercury in certain kinds of locally-caught fish. 

According to state-issued advice for lakes and reservoirs in California, rainbow trout are the only fish species with low enough mercury levels for pregnant women and young children to eat twice a week, unless the lake has site-specific advice that identifies other low-mercury species.

California’s authority on fresh water fish consumption is the Office of Environmental Health Hazard Assessment (OEHHA). OEHHA issues Fish Advisories and Safe Eating Guidelines specific to fishing locations throughout the state.  When site-specific information is not available, OEHHA offers advice for all California lakes and reservoirs that do not already have site specific advice and general advice to help people avoid fish that have high levels of mercury.

The OEHHA fish consumption advisory for lakes and reservoirs in CA recommends that, unless alternative site-specific guidelines exist, due to high levels of mercury women under 45 and children under 18:

  • Do not eat any bass, carp or large brown trout caught from lakes or reservoirs;
  • That they only eat one serving per week of bullhead, catfish, bluegill, sunfish or brown trout under 16 inches; and
  • That they may eat up to two servings per week of rainbow trout.

Fish consumption advisories about mercury are due to the fact that mercury accumulates in fish tissue.  In water bodies, the chemical form of mercury changes to the more toxic organic form, methylmercury, which builds up in fish and other organisms. Methylmercury can cause harm to the nervous system.  Unborn babies and children are particularly susceptible to this effect because their nervous systems are still developing.

The new federal recommendations stress that eating fish has multiple nutritional benefits to pregnant women, to developing fetuses and to young children, but exposure to too much mercury can have an adverse effect on fetal and neurodevelopment.  Whether you eat seafood, or locally caught inland fish, be sure to choose lower mercury fish.

Additional resources on mercury in fish: