Benefits and risks of eating fish

Fish are a healthy source of lean protein, nutrients, and omega-3 fatty acids. Omega-3 fats contain two components that are important for good health: docosahexaenoic acid and eicosapentaenoic acid. Recent studies have shown that DHA and EPA help reduce inflammation in the body. Because of this ability, they appear to reduce the symptoms associated with medical conditions that are initiated by inflammatory processes. For example, supplementation with DHA and EPA may reduce the severity of symptoms related to rheumatoid arthritis, asthma, and migraine.

Furthermore, DHA and EPA have also been shown to help lower triglycerides and raise good cholesterol, often called HDL, which leads to a reduction in blood pressure, heart rate and the risk of heart disease. Adequate levels of DHA and EPA have also been shown to help prevent depression and other mental health issues, and reduce age-related declines in memory. In addition, DHA and EPA may help prevent certain kinds of cancer and eye disease.

Adequate levels of DHA and EPA are extremely important for pregnant women in that these fatty acids are necessary for proper development of the fetal brain. They also help prevent miscarriage and premature delivery. Several studies have suggested that DHA supplementation during pregnancy may lead to higher intelligence in children. Overall, eating fish, such as salmon and albacore tuna, that are high in DHA and EPA, has many positive health benefits.

Although eating fish is highly beneficial, there are potential risks. Some fish contain large quantities of toxicants such as mercury, which is a heavy metal that is released into the environment by industrial processes such as coal-fired power plants and gold mining. Mercury in the atmosphere settles into rivers, lakes and oceans, where it accumulates in the tissues of fish. Large fish such as shark, swordfish and king mackerel have higher levels of mercury while fish such as salmon and albacore tuna have relatively low levels of mercury.

It was once thought that the majority of mercury contamination was limited to saltwater fish. However, in a recent study, the U.S. Environmental Protection Agency tested fish in nearly 80,000 freshwater lakes across the U.S. and reported that every fish tested contained mercury. Nearly one-half of those fish contained levels of mercury that were considered to be unsafe by the EPA.

As a result of this study, new guidelines for fish consumption were developed. For a healthy individual, the EPA recommends no more than two meals of fish per week. In Middle Georgia, fish advisories exist for the Ocmulgee River. While there are no restrictions on eating catfish, the Georgia Department of Natural Resources recommends that individuals eat no more than one meal of largemouth bass each week. Exposure of pregnant women to mercury can lead to developmental delays and other neurological impairments in the developing fetus and young children. Therefore, pregnant women, women who want to become pregnant, breastfeeding women and children are urged to use caution when eating fish.

The EPA recommends that individuals in these groups eat no more than 8-12 ounces of fish per week. These fish should be species that tend to be low in mercury (e.g., salmon, tilapia). In general, it appears that the benefits of consuming fish that are low in mercury during pregnancy may out-weigh the risks associated with the exposure to mercury.

This story was originally published March 31, 2017 at 4:10 PM with the headline "Benefits and risks of eating fish."