The importance of fish as a source of vitamins, minerals, and omega-3 fatty acids is widely known. But mercury concentration in fish is also well-known, and it varies among the numerous varieties of tuna. Ahi, albacore, and bigeye are the varieties with the highest mercury concentrations.
Ahi and bigeye tuna are widely used raw in sushi, according to tuna connoisseurs, whereas albacore is one of the main forms of tuna used in canned variations. Mercury content in albacore, also referred to as canned white tuna, is roughly 0.32 parts per million. A different kind of canned tuna is also available, but it is a canned light tuna derived from skipjack tuna. Mercury content in canned light tuna is only 0.12 parts per million.
You shouldn’t consume mercury too frequently because it’s a potential poison. Adults should only consume small amounts of tuna due to this. Women should consume three 6-ounce portions of albacore tuna per month, while males can consume three 8-ounce portions. Depending on their age, children should consume no more than two 4.5-ounce portions or one 3-ounce portion every month.
You may consume more canned light tuna than albacore without risk. This kind of tuna is safe to eat once a week for adults and kids over the age of six. You could become poisoned by mercury if you consume more than is advised. Tuna with high mercury content may have negative impacts.
Mercury poisoning can cause loss of coordination, memory issues, numbness, pain, vision issues, seizures, and tremors, among other symptoms. If you are pregnant, mercury poisoning can interfere with the development of your unborn child.
Although mercury has a bad reputation among fish elements, other poisons can also be present and have an impact on our health, frequently as a result of contaminated water. These toxins include lead, cadmium, and arsenic.
The good news is that, as long as you consume the authorized amounts of tuna, these heavy metals rarely reach concentrations that should worry you. The unfortunate news is that these pollutants may be found anywhere, from Brazil to Ghana to Iran. Conclusion: Eating tuna fish every day has no advantages, despite the fact that it is delicious and healthful. Even canned tuna shouldn’t be consumed in excess because it’s hazardous for your long-term health.
What Fish Oil Supplements Do in Reality
Seven percent of participants in the University of California study said they consumed more than 20 tuna dinners per week. Further tests on some youngsters’ hair revealed mercury concentrations above what is deemed “a level of concern.”
High mercury levels can cause a variety of signs and symptoms as well as health issues. These symptoms can include more obvious ones like rosy cheeks and swelling in specific body regions, as well as itching, burning, or even the sense that tiny insects are crawling under one’s skin. Mercury poisoning can have more severe effects, such as high blood pressure, poor cognitive function, blindness, and problems with the kidneys and lungs. The risks can be considerably more serious for women who are pregnant.
“Your baby can develop mercury toxicity much more readily since they are obviously smaller than the usual human, and that can potentially lead to things like cosmetic defects or stillbirths,” explains Melanie. But if you’re a typical person going about your daily business and eating tuna as a bit of a mainstay, I wouldn’t anticipate too many issues.
In conclusion, sure, there is such a thing as too much tuna. However, you would have to consume several hundred grams of tuna every day for a number of months before you started experiencing any severe issues. Melanie argues that the more pertinent worry for people who insist on eating that much is that they would probably forego other foods and minerals in favor of canned fish.
Although tuna is a nutrient-dense food, she emphasizes that it should still be consumed in conjunction with dairy, whole grains, vegetables, fruits, and healthy oils. “That said, someone could experience mercury toxicity if they have such severe food allergies that they are severely restricting their diet—or maybe they’ve just chosen to put themselves on some type of crazy diet for whatever reason.”
So, like with everything in life, moderation is the key. Sure, tuna is a fantastic source of iron, zinc, omega 3 fatty acids, and protein. However, it is also a somewhat reliable source of mercury. Even while the hazards may eventually outweigh the health advantages, it’s usually preferable to limit your intake to one can each day.
Mercury is included in canned tuna, therefore consuming too much of it can cause mercury poisoning.
According to a research published in Environmental Health Perspectives, tuna caught in the Pacific Ocean accounts for 40% of all human exposure to mercury in the United States, which accounts for more than 90% of exposure from eating ocean fish and shellfish.
In lakes, rivers, and oceans, mercury from coal-fired electricity generation and other human industrial operations settles and is eaten by marine life. However, scientists writing in the journal Global Biological Cycles claim that the organic carbon decay process in nature also contributes to the presence of mercury in seas. Regardless of how mercury enters the water, microorganisms convert it into methylmercury, a highly toxic form that accumulates in the flesh of fish that we consume. Because methylmercury bioaccumulates in bigger predators, eating larger fish like tuna poses a greater risk than eating, say, sardines. (Related: A Dietitian’s Pick for the #1 Fish to Eat.)
The Weekly Maximum Permissible Tuna Consumption
Consumers have traditionally favored tuna as a food. In fact, the National Fisheries Institute estimates that Americans consume a staggering one billion pounds of canned (or pouched) fish per year. However, as many are aware, consuming too much of this lunchtime staple can result in mercury exposure.
According to LiveStrong, eating more tuna than is recommended each week can lead to an increase in the neurotoxic mercury exposure. Several alarming neurological symptoms, such as loss of coordination, memory issues, seizures, and tremors, can be brought on by mercury poisoning. Other symptoms of mercury poisoning, according to the Environmental Protection Agency, include loss of peripheral vision, difficulties with speech, hearing, or mobility, muscle weakness, and a numb, “pins and needles” sensation in the hands, feet, or lips.
Fortunately, it’s not too difficult to ensure that eating seafood won’t raise your mercury levels. Simply monitor your tuna intake and add other fish to your diet as needed to balance it out.
How much tuna should I consume each week? The explanation of mercury toxicity in science
Canned tuna is a fantastic, cost-effective source of protein, polyunsaturated fats, and other nutrients, costing as low as AU$1 ($0.75) per tin. Much less expensive than many varieties of fresh meat or seafood is a can of tuna.
“Everyone can safely eat canned tuna as part of their seafood consumption, including expectant women. Due to the usage of smaller tuna species and the fact that the tuna are typically younger when collected, canned tuna typically has lower mercury levels than tuna fillets.”
Depending on your body weight and the specific brand of tuna you purchase, laboratory tests we conducted for the ABC TV science program Catalyst in 2015 indicate that you could consume anywhere between 25 and 35 small tins (95g or 3.3 ounces each) of tuna per week before exceeding the maximum mercury limits.
Can eating too much tuna make you sick?
Eating seafood, particularly fish, is predominantly responsible for methylmercury (organic mercury) poisoning. Fish toxicity has two root causes:
- consuming specific seafood that carry mercury
- overindulging in fish
Mercury enters fish through the water they are in. There is some mercury in every kind of fish. Because they prey on other fish that also contain mercury, larger species of fish may have higher concentrations of mercury.
Among these, sharks and swordfish are among the most prevalent. King mackerel, marlin, and bigeye tuna all have significant mercury concentrations.
Additionally, consuming too much seafood carries the risk of developing mercury poisoning. You can eat the following varieties of fish once or twice a week in moderation:
- ahi albacore
Despite the fact that these selections generally contain less mercury, you should be cautious about how much you eat.
The March of Dimes advises consuming no more than 6 ounces of tuna and 8 to 12 ounces of other forms of fish per week if you’re expecting. This will lessen the danger of exposed fetal mercury.
If you’re nursing, you’ll also want to be cautious about how much fish you eat because mercury can transfer through breast milk.
If you consume too much fresh tuna, what happens?
Some tuna kinds may have high levels of mercury, a heavy metal that enters the ocean as a result of pollution. As the fish moves up the food chain and ingests mercury-containing smaller fish, it slowly builds up in tuna over time (14).
Large kinds of tuna like albacore, yellowfin, bluefin, and bigeye are hence frequently rich in mercury (15).
These kinds account for the majority of the raw tuna used in steaks, sushi, and sashimi dishes.
In fact, a research in the northeastern United States that examined 100 samples of raw tuna sushi discovered that the average mercury content was higher than the advised daily limit for mercury in both Japan and the United States (16).
If you eat a lot of raw tuna, your body may have excessive mercury levels, which can harm your heart and brain and cause other major health problems (16, 17, 18).
Bigeye and bluefin tuna in particular may contain extremely high levels of mercury when consumed raw. Too much mercury in your diet can harm your heart and brain and cause major health problems.
Can I consume two tuna cans each day?
Despite having a high nutritional value, tuna has a higher mercury content than the majority of other fish. Consequently, it should only be consumed sometimes rather than daily. You can occasionally have skipjack and light canned tuna together with other low-mercury seafood, but you should limit or stay away from albacore, yellowfin, and bigeye tuna.
How many tuna cans per week are okay to consume?
1. What distinguishes albacore (white) tuna from light tuna in cans?
Compared to the fish often used to make canned light tuna, albacore, or white tuna, is bigger and lives longer. In contrast, canned light tuna may contain a combination of different, mostly smaller tuna species, most frequently skipjack.
2. Due to how reasonably priced canned light tuna is, I consume a lot of it. Is this alright?
Yes. Two to three servings of canned light tuna per week are acceptable because it is one of the “Best Choices” options. We advise you to eat a range of fish. You might want to try some of the other reasonably priced fish in the “Best Choices” section, like frozen fish or fresh fish that is on sale, canned salmon or sardines, or frozen fish.
3. Although I eat a lot of tuna, albacore tuna is my favorite type. Is this alright?
White tuna, sometimes referred to as albacore tuna, typically has mercury levels three times higher than canned light tuna. You should only consume one serving of albacore tuna or any other seafood from the “Good Choices” category per week.
I wonder why I want tuna.
This is due to the fact that tuna is an excellent source of protein, healthful fats, omega three fatty acids, and vitamins A and D.
Your body need more calories, protein, and good fats when you are pregnant than usual.
Therefore, if you start to crave tuna when pregnant, it is quite natural and you should indulge. An excellent suggestion is a tuna sandwich.
To be safe, it is best to always purchase Skipjack tuna in cans (further information about canned tuna is provided below)!