Is Mercury in Fish Bad for You?

Fish are vital for a healthy diet, providing nutrients essential for brain development. Although there is mercury in fish, if you follow guidelines, fish consumption is safe for all including pregnant people and children. Based on leading studies, researchers at URMC explain the balance of fish benefits and mercury risks.

What are the benefits of eating fish?

Fish are a rich source of important nutrients important to the brain and a healthy diet, including:

Recent findings show that the fatty acids in fish enhance developmental and educational outcomes and may even help protect the developing brain from the harmful effects of mercury.

Why is there mercury in fish?

Methyl mercury is generated by industrial pollution and natural events (like volcanoes). It ends up in the oceans and other bodies of water and makes its way up the food chain. Consuming seafood is one of the primary ways humans are exposed to mercury.

Is it safe to eat fish?

For adolescents and adults, there are no real mercury-related health concerns associated with eating a normal diet of seafood. For many people on the planet, fish are the primary source of protein. If you eat a lot of seafood, fish consumption guidelines recommend that your diet has a healthy balance of low mercury fish.

The question gets more complicated when it comes to pregnant and breastfeeding mothers and young children. Loralei L. Thornburg, MD, a professor of Obstetrics and Gynecology at URMC, explains, “Seafoods, and fish in general, are great sources of lean protein, micronutrients, and amino acids that we know that are critical to fetal brain development and a healthy baby.”

Weighing the health benefits of fish with the risks of mercury exposure is complex. Recommendations have evolved over time, which can be confusing. “The key is finding the right balance; too much is problematic, but so is not enough,” said Thornburg.

Too much can be problematic as mercury is a neurotoxicant. This means that it may cause damage to the brain in the early stages of development. There is a growing body of scientific evidence that the benefits of eating fish outweigh the risk of mercury exposure when it comes to brain development. This is reinforced by decades of URMC-led research that find no link between a maternal diet high in fish and deficits in the cognitive development and learning ability of their children.

How much fish should I eat?

Large predatory fish like shark and swordfish typically have high concentrations of mercury. If you catch the fish you eat, pay attention to local fish advisories.