Fish Consumption During Pregnancy & Breastfeeding: An Interview with James Allen McGregor, MDCM

James A. McGregor, MDCM is Visiting Professor of Obstetrics & Gynecology at the University of Southern California’s Keck School of Medicine and is author of more than 200 publications and a contributor to several books, videos and Web sites. Dr. McGregor has a special interest in infectious diseases and optimizing each child’s potential capacity for learning. He joined the USC Division of Maternal-Fetal Medicine in 2004. Our interview with Dr. McGregor offers important information about nutrition for women who are pregnant or breastfeeding.

Q. What are the potential health benefits for individuals and families who include fish in their diet?

A. All women and their families have plenty of reasons to include seafood and other sources of omega-3 fatty acids in their diets. Many leading national health organizations advise consumers to take advantage of the health benefits of fish by including it as part of a balanced, healthy diet along with a diversity of fresh foods. The American Dietetic Association recommends eating fish in two to three meals per week, pointing to fish as a low-fat source of protein that can help lower cholesterol. The American Heart Association also recommends eating fish for the significant heart health protection it offers, as well as for the beneficial effects of omega-3 fatty acids on other conditions, such as inflammatory and autoimmune diseases, as well as possible prevention of dementia. In addition, the new Dietary Guidelines for Americans issued in 2005 by the US Department of Agriculture (USDA) and the Department of Health and Human Services (DHHS) encourages consumers to eat fish to get these same health benefits from the omega-3 fatty acids. Fish provides these health benefits to individuals of all ages, including children and women who are planning a pregnancy.

Q. Are there particular health benefits from consuming fish during pregnancy and breastfeeding?

A. In addition to the many other benefits that come from including seafood in a balanced diet, the essential omega-3 fatty acids found in fish – DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) – are especially beneficial for pregnant and nursing women. For example, canned tuna contains DHA, an omega-3 fatty acid that is essential for the healthy development of the fetus and young child. DHA makes up approximately 40 percent of the myelin coating brain cells and 60 percent of cell membranes in the retina. DHA is transferred from mother to fetus at a high rate during the third trimester of pregnancy. Also, some evaluations have shown increased brain function in children of mothers who ate increased amounts of seafood or fish oil during pregnancy, and other studies have shown that eating seafood can help optimize pregnancy lengths. It is because seafood is so important to a pregnant and nursing woman’s diet that the US Food and Drug Administration (FDA) and Environmental Protection Agency (EPA) have issued their most recent seafood advisory, which tells them how to get the benefits of fish without compromising the safety of their diet. According to the government advisory, “Fish and shellfish are an important part of a healthy diet…So women and young children in particular should include fish or shellfish in their diets, due to the many nutritional benefits.”

Q. What advice about eating fish do government authorities give to pregnant and breastfeeding women?

A. In March 2004, the FDA and EPA issued a joint advisory to help pregnant women and breastfeeding mothers choose fish that are safe because of their low levels of mercury pollution. FDA and EPA have identified five commonly served fish with very low mercury levels: shrimp, salmon, pollock, catfish and canned light tuna. According to the government’s advisory, pregnant and nursing women, women who might become pregnant and young children can safely eat up to 12 ounces (four standard 3 ounce servings) of these fish weekly. The government advisory also tells pregnant and nursing women that they can safely eat up to six ounces a week of canned albacore tuna (there are about two ounces of albacore in a typical serving). However, the advisory also identifies types of fish that have higher levels of mercury and should be avoided by pregnant and nursing women, women who might become pregnant and young children: Shark, swordfish, tilefish and king mackerel.

Q. What is mercury, and why does it affect fish?

A. Mercury is a naturally-occurring but potentially poisonous metal. Mercury is used in products such as batteries and dental fillings, and is emitted from power plans and other industrial activity. These emissions pollute our oceans, lakes, rivers and streams, accumulating in the bodies of fish and leaving some of them (especially “top of the food chain” predators) with toxic levels of mercury. Eating contaminated fish exposes humans to mercury.

Q. Why is mercury a special concern for pregnant and nursing women?

A. In small amounts, mercury is not harmful to humans, but at high exposure levels it can be toxic, damaging the nervous system, lungs, kidneys, vision and hearing. The seriousness of the risk depends upon how much mercury a person is exposed to, and the risk is greatest for fetuses and children. The main concern is that mercury may harm an unborn baby’s or young child’s developing nervous system, if pregnant and nursing women consume large amounts of fish that contain high levels of mercury. The restrictions put in place by the federal government, including the advice they have issued for pregnant and nursing women and those who may become pregnant, reduces risks of exposure to mercury pollution.

Q. How can the National Healthy Mothers, Healthy Babies Coalition and its partners in maternal-child health help women make informed, healthy choices about fish consumption?

A. We in the maternal and child health field can share with women the important message that the recommended seafood is part of a healthy, well-rounded diet – and in particular, that seafood offers special health benefits to pregnant and breastfeeding women and their children. By being aware of the latest science and the recommendations of leading health authorities regarding fish consumption, we are in a position to dispel myths and help women to be informed consumers – the best possible advocates for themselves and their families.

For more information, see American College of Obstetricians and Gynecologists (ACOG) publications, such as “Nutrition During Pregnancy”