You Should Avoid This Type Of Canned Tuna, According To The FDA

Tuna is a great source of omega-3 fatty acids that can lower your LDL cholesterol, reduce inflammation, and even hinder the growth of some tumors, according to WebMD. You've probably grown up with tuna fish sandwiches as a healthier alternative to those fried fish sticks. Although the Dietary Guidelines for Americans suggest eating fish two to three times a week, the Food & Drug Administration says you'll want to avoid certain types of fish, especially if you're pregnant. That's because certain types of fish have higher amounts of mercury than others.

There are a number of popular canned tuna varieties, but the most well-known is albacore. In general, albacore is considered safe to eat — though a 2023 analysis from Consumer Reports cautions that some brands of canned albacore tuna are high in mercury. Light canned tuna is primarily made of skipjack tuna, another relatively safe fish. Unfortunately, chunk light often contains other types of tuna. This can include bigeye, which the FDA specifically advises against eating. Bigeye tuna, which is often used in sushi, has some of the highest levels of mercury, so pregnant women and children under 12 should avoid this type of tuna.

Why certain tuna are high in mercury

Mercury is found in almost all fish you eat, according to Consumer Reports. Although mercury is a natural element found in nature, pollution from coal-powered industries often contributes to higher levels of mercury in the environment. Mercury is a neurotoxin that is harmful to developing bodies and brains, which is why children and pregnant women should limit their exposure to mercury in food. Mercury can also affect motor coordination, speech, and sleep if adults consume it in higher concentrations.

Because larger fish tend to eat smaller fish, mercury levels tend to be higher in larger fish, like bigeye tuna. Mercury levels might also depend on where your fish is caught. SUNY Stony Brook Professor of Marine and Atmospheric Science Nicholas Fisher, Ph.D., told Consumer Reports that tuna caught in the Pacific Ocean have rising levels of mercury because China and India burn more coal, which releases mercury into the air. Mercury levels in the Atlantic Ocean are slightly dropping because of efforts to reduce emissions from coal-fired plants. 

Choosing fish lower in mercury

Consumer Reports suggests that nonpregnant adults can safely eat three cans of chunk light or skipjack tuna a week and stay within a safe range of mercury levels. It might still be okay to eat albacore tuna once a week, but you might have to keep an eye on the mercury in other types of fish you eat. King mackerel, orange roughy, shark, and swordfish have unhealthy levels of mercury.

According to the FDA, Atlantic mackerel, tilapia, catfish, haddock, pollock, trout, and salmon are considered some of the best choices for their levels of mercury. If you prefer shellfish, mercury is low in shrimp, oysters, clams, crab, and crawfish. If you're worriesd about mercury levels, you don't need to cut out fish altogether. Just pay attention to the types of fish that you're consuming, read the nutritional labels, and stick to the FDA's serving recommendations.