Can Eating Tuna Every Day Be Harmful?

Eating tuna every day may increase mercury levels in your body.
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The American Heart Association recommends eating omega-3-rich fish, such as tuna, twice a week for good health. It's wise, however, to include variety in your tuna diet.


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Because tuna is a source of mercury, you should avoid eating tuna everyday, especially higher-mercury varieties like albacore tuna. If tuna makes a regular appearance in your diet and you're concerned about how it may affect your health, consult your doctor.

Read more: Canned Tuna May Not Be as Healthy as You Thought



While tuna is low in calories and high in protein, certain varieties contain significant amounts of mercury. Avoid eating tuna everyday to reduce risk of mercury poisoning from tuna.

Tuna Health Benefits

The 2015-2020 Dietary Guidelines for Americans reports that most Americans don't eat enough seafood. For those trying to increase the seafood content of their diets, tuna makes a convenient choice because it's readily available and fairly inexpensive. Plus, there are tuna health benefits — it's low in calories and a good source of protein.


According to the USDA, a 3-ounce portion of canned light tuna packed in water has 73 calories, 17 grams of protein and less than 1 gram of fat. The same serving of canned white (albacore) tuna packed in water has 109 calories, 20 grams of protein and 2.5 grams of fat.

Although a little pricier, fresh yellowfin tuna also makes a healthy choice with 93 calories, 21 grams of protein and less than 0.5 grams of fat per 3-ounce raw portion.


Dangers of Eating Tuna Everyday

If you consume a lot of fish, you could be at risk for mercury poisoning from tuna. Mercury is a poisonous metal that can have serious health consequences, such as injury to the brain, heart, kidneys and lungs. It's especially harmful to children and pregnant women because it can affect development of the child and growing fetus.

According to the Natural Resources Defense Council, air pollution from coal-burning factories is the major cause of mercury in the environment. Rainfall transfers the mercury pollutant to the water where it is absorbed by the fish.

Larger fish like tuna tend to have higher concentrations of mercury because they get it not only from the water, but from the fish they eat. According to the Environmental Protection Agency, bigeye tuna contains 0.69 micrograms of mercury per gram. However, canned light tuna contains significantly less, with 0.13 micrograms per gram.

According to the 2015-2020 Dietary Guidelines for Americans, adults should consume 8 or more ounces of fish per week. Pregnant or breastfeeding women should consume 8 to 12 ounces per week, while avoiding those higher in mercury, such as fresh tuna.

Read more: Results of the Tuna and Water Diet

Making Tuna Good for You

If you're buying canned tuna, select tuna packed in water to cut calories. If you're making a tuna salad, use small amounts of mayonnaise and add plenty of veggies such as diced celery, peppers and carrots. Also, consider replacing mayonnaise with nonfat yogurt.

For fresh tuna, select fish that has no discoloration or strong odor and cook within 2 days of purchase, as advised by the U.S. Food and Drug Administration (FDA). Pat your fresh tuna dry before cooking, then grill, pan fry or broil until done to your liking, usually about 2 minutes per side.

Also, to get your weekly seafood needs for good health, mix it up. Include different types of fish in your diet that have less mercury but are good sources of omega-3s, such as salmon, anchovies and sardines. Also include other types of seafood or fish, such as shrimp, scallops, tilapia and haddock.