Research funded by the National Institute of Environmental Health Sciences (NIEHS) has discovered that cognitive function in adults improved with aerobic fitness. However, adults who were exposed to high levels of mercury before birth did not experience brain-based benefits from exercise such as faster cognitive function and improved short-term memory.
The team at NIEHS examined how high prenatal exposure to methylmercury affected cognitive processing in adults. Mercury exposure, which results from industrial pollution from air that falls into water and accumulates in fish, is toxic to the brain and nervous system. This exposure may limit the ability of the nervous system tissues to form and grow when aerobic fitness is increased to promote a healthy lifestyle. Gwen Collman, Ph.D., director of the NIEHS Division of Extramural Research and Training, says, “This research points to adult cognitive function as a new area of concern.”
Researchers divided 197 participants into two groups based on the methylmercury levels during their prenatal development. The Faroe Islands residents had been tracked by scientists since the late 1980s – when they were still in utero. The study discovered the brain benefits of exercise were specific to those with lowest exposure.
According to Collman, aerobic exercise is crucial for a healthy lifestyle, but the results suggest early-life exposure to pollutants may hinder the potential advantages. Women of childbearing age and children are recommended to eat two to three weekly servings of low mercury fish, according to the U.S. Food and Drug Administration. Salmon, shrimp, pollock, tilapia, catfish, cod, and canned light tuna are low mercury fish, ideal for supporting this healthy diet. Fish to avoid due to their high levels of mercury include tilefish from the Gulf of Mexico, king mackerel, shark, and swordfish.