Tuna is a nutritious and protein-rich saltwater fish that may contain high levels of mercury. As a result, regular tuna consumption may lead to health issues.
Mercury contamination in fish, particularly tuna, has raised significant concerns for consumers and health experts alike. As one of the most widely consumed fish species, tuna can accumulate high levels of mercury due to its position at the top of the food chain.
While tuna is a rich source of protein and omega-3 fatty acids, questions about its safety—especially for pregnant women, children, and frequent consumers—have sparked ongoing debates.
Read on to learn more about the risks associated with mercury in tuna, the potential health effects, and how to make informed choices when incorporating this popular fish into your diet.
Tuna contains more
This is because tuna feed on smaller fish which are already contaminated with varying amounts of mercury. Since mercury is not easily excreted, it builds up in the tissues of tuna over time.
Levels in different species
Levels of
| Species | Mercury in ppm | Mercury (in mcg) per 3 ounces (85 g) |
|---|---|---|
| Light tuna (canned) | 0.126 | 10.71 |
| Skipjack tuna (fresh or frozen) | 0.144 | 12.24 |
| Albacore tuna (canned) | 0.350 | 29.75 |
| Yellowfin tuna (fresh or frozen) | 0.354 | 30.09 |
| Albacore tuna (fresh or frozen) | 0.358 | 30.43 |
| Bigeye tuna (fresh or frozen) | 0.689 | 58.57 |
Mercury in tuna is a health concern because of the risks associated with mercury exposure.
Just as mercury builds up in fish tissues over time, it can also accumulate in your body. To assess how much mercury is in your body, a doctor can test mercury concentrations in your hair and blood.
High levels of mercury exposure may lead to brain cell death and result in impaired fine motor skills, memory and focus.
Mercury buildup is also linked to a higher risk of heart disease. This may be due to mercury’s role in fat oxidation, a process that can lead to this illness.
Tuna is incredibly nutritious and packed with protein, healthy fats and vitamins — but it should not be consumed every day.
The
However, research indicates that regularly eating fish with a mercury concentration greater than 0.3 ppm may increase blood levels of mercury and spur health issues. Most species of tuna
Therefore, most adults should eat tuna in moderation and consider choosing other fish that is relatively low in mercury.
When buying tuna, opt for skipjack or canned light varieties, which do not contain as much mercury as albacore or bigeye tuna.
You can consume skipjack and canned light tuna alongside other low-mercury species, such as cod, crab, salmon and scallops, as part of the
Try to avoid eating albacore or yellowfin tuna more than once per week. Refrain from bigeye tuna as much as possible.
Certain populations are especially susceptible to mercury and should limit or completely abstain from tuna.
These include infants, young children and women who are pregnant, breastfeeding or planning to become pregnant.
Mercury exposure can impact embryo development and may lead to brain and developmental issues.
In a 2019 review of maternal consumption of seafood and childhood and neurocognitive development, evidence indicates that consumption of at least 4 oz of fish a week but less than 12 oz total of a wide range of commercially available seafood during childhood through adolescence has beneficial associations to a wide spectrum of neurocognitive outcomes as compared to consuming no seafood.
Mercury exposure is linked to health issues including poor brain function, anxiety, depression, heart disease and impaired infant development.
Though tuna is very nutritious, it’s also high in mercury compared to most other fish.
Therefore, it should be eaten in moderation — not every day.
You can eat skipjack and light canned tuna alongside other low-mercury fish a few times each week, but should limit or avoid albacore, yellowfin and bigeye tuna.
