The hills of North Carolina aren't known for fresh seafood.
During a recent visit, I was surprised to find the daily specials in two restaurants were a dangerous type of fish... tilefish.
Tilefish are large, predatory fish with long life spans, averaging 39-46 years.
It's also the No. 1 fish that the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) advise against eating.
We're all familiar with mercury. It's that super toxic, shiny substance. It was – and still is in some countries – used in thermometers. There's a reason why the U.S. phased out mercury thermometers. Mercury is known to cause neurological problems in babies and the elderly.
Some symptoms of mercury poisoning include itching and skin discoloration. Mercury poisoning can also cause sensory impairment, inflammation of the digestive tract, and even death.
Mercury poisoning rarely happens quickly... It usually happens over time as your body stores mercury you've been exposed to... like if you eat a lot of fish high in mercury.
When it comes to fish, certain species – like tilefish – often have high concentrations of mercury.
Mercury concentrates in fish higher in the food chain. Small fish and ocean animals have less, but each larger fish up the chain eats the smaller fish and concentrates the poisons. This is even worse in fish that live longer, since there's more time for mercury to build up.
According to the FDA, tilefish contain mercury levels of 1.45 parts per million (ppm). Compare that to 0.003 ppm in scallops. Other fish that have high levels of mercury are swordfish (0.99 ppm), shark (0.98 ppm), mackerel king (0.73 ppm), and bigeye tuna (0.69 ppm). You can view a list of fish and the mercury in them here.
Does this mean you should avoid fish?
Don't Let Mercury Fears Stop You From Eating Fish
Eating fish is good for you. In fact, studies from Harvard and the Journal of the American College of Cardiology found that people who eat at least two servings of fish per week were 36% less likely to die from heart disease.
As a food, fish is low in carbohydrates, high in protein, and moderately high in fat. The fat composition of fish is the important issue...
Fish meat is low in saturated fats. This is good because too much saturated fat is thought to be harmful. In fish, the two fats providing benefits are the monounsaturated and the polyunsaturated fats. Monounsaturated fat is what makes up olive oil and is well-known to aid heart health. Fish contains some of all three kinds of fats, but the majority is polyunsaturated.
The polyunsaturated oils have special chemical bonds along the chain of carbon atoms (oils are just strings of carbon atoms of various lengths). When the bond is on the third carbon, we call it an omega-3 fat.
Although the reasons aren't clear, omega-3 fats (from fish as well as other sources) reduce inflammation... Inflammation increases your risk of heart disease, diabetes, and aging. So there are significant health benefits to eating fish.
But it's important to eat the right kinds of fish so you can enjoy them safely.
When you're eating fish, do what I do... Eat fish lower in mercury – like salmon, light tuna, catfish, and tilapia.
What We're Reading...
- The Environmental Working Group's warning for women... Current guidelines may expose babies to too much mercury.
- Something different: Coffee loses its "carcinogen" label.