In general, it is safe for all population groups, including pregnant women, to consume 2-3 serves of any type of tuna per week (canned or fresh). Canned tuna generally has lower levels of mercury than other tuna because the tuna used for canning are smaller species that are generally caught when less than 1 year old.
Canned white, or albacore (0.32 parts per million of mercury). Children under six can eat up to one 3-ounce portion a month; children from 6-12, two 4.5-ounce portions a month. Adults, including pregnant women, can safely eat this kind of tuna up to three times a month (women, 6-ounce portions; men, 8-ounce portions).
You would have to eat around 25 tins (at 95g a tin) of it a week before you hit the maximum tolerable intake of mercury. For pregnant people (or people trying to get pregnant), the limit would be around 12 tins (at 95g a tin) a week.
Canned light tuna is in the “Best Choices” category and it is fine to eat 2 to 3 servings per week. We recommend that you eat a variety of fish.
Canned light tuna is low in mercury and is considered one of the best choices for individuals that need to limit their exposure to mercury. People who are pregnant or breastfeeding can consume 2–3 servings of canned light tuna per week and children can consume 2 servings per week.
Since tuna is relatively high in mercury, one can per day would bring you to the FDA suggested maximum amount of mercury. Having more than that on occasion may not be a problem, but you are at risk of getting low dose sustained mercury poisoning.
Eating more than the advised amount of tuna each week can result in increased exposure to the neurotoxin. Mercury poisoning can cause several concerning neurological symptoms, including coordination loss, memory problems, seizures, and tremors.
Fifty-four percent of those students reported eating tuna about three times a week, while more than 99 percent reported low knowledge of the potential dangers associated with overconsumption—most notably, mercury poisoning. It's no secret that tuna, like most fish and shellfish, contains toxic, heavy metal mercury.
The truth is, those warnings never applied to the general public. However, it is possible for adults to get mercury poisoning. You just have to eat a lot of high-mercury fish for that to happen. Our advice: Almost all guys will be perfectly fine eating a can of light tuna four times a week.
Once in the body mercury has a half-life of ~3 days in the blood stream and a 90 day half life in other tissues (e.g. brain, kidneys, etc).
But scientists say more tests are needed to confirm that. Cooking does not remove mercury from fish because the metal is bound to the meat. For example, a piece of tuna will have the same amount of mercury whether it is eaten raw as sushi or cooked on the grill.
Most of the metallic mercury absorbed into the body eventually leaves in the urine and feces, while smaller amounts leave the body in the exhaled breath.
Tuna: if you are trying for a baby or are pregnant, you should have no more than 4 cans of tuna a week or no more than 2 tuna steaks a week. This is because tuna contains higher levels of mercury than other fish. If you are breastfeeding, there is no limit on how much tuna you can eat.
Canned light tuna is the better, lower-mercury choice, according to the FDA and EPA. Canned white and yellowfin tuna are higher in mercury, but still okay to eat.
Elemental (Metallic) Mercury
Metallic mercury mainly causes health effects when inhaled as a vapor where it can be absorbed through the lungs. Symptoms of prolonged and/or acute exposures include: Tremors; Emotional changes (such as mood swings, irritability, nervousness, excessive shyness);
Mercury is toxic to humans. There is no standard cure for mercury poisoning, so it is best to avoid exposure to high amounts of mercury when possible. Eliminating risk factors by making changes in the diet and work or living environment may help reduce the levels of mercury in the body.
Be smart about sushi and sashimi.
Many varieties can have high mercury contents, as sushi-grade fish tend to be larger and older. Go easy on (or avoid) all forms of tuna, including bluefin, yellowfin, bigeye and albacore. Same goes for mackerel, sea bass and yellowtail.
"One big takeaway is that albacore has much more mercury than light or skipjack tuna, regardless of the brand," Consumer Reports said. "That's not surprising, since albacore is larger and lives longer than the tunas that make up the light tuna or skipjack tunas.
Salmon is low in mercury.
Farmed salmon has on average, 0.05 micrograms of mercury per gram. This is well below the levels deemed safe for women and children by the FDA and EPA, which inform the United States Dietary Guidelines for Americans (DGA).
You can safely eat up to 6 ounces of tuna steak each week, the United States Environmental Protection Agency reports.
In general, it is safe for all population groups, including pregnant women, to consume 2-3 serves of any type of tuna per week (canned or fresh). Canned tuna generally has lower levels of mercury than other tuna because the tuna used for canning are smaller species that are generally caught when less than 1 year old.
Mercury poisoning is diagnosed by testing your blood and urine for mercury levels. Urine might be collected over a 24-hour period. Your doctor will ask about the history of your possible exposure and may also monitor your temperature, pulse rate, blood pressure and breathing.
Canned light tuna contains the least amount of mercury, and the FDA suggests limiting yourself to no more than 12 ounces a week, or no more than three 5-ounce cans.