What Is the Healthiest Tuna to Eat: Species Compared

Skipjack tuna is generally the healthiest species for regular eating, combining low mercury levels, solid omega-3 content, and wide availability at a reasonable price. But “healthiest” depends on what you’re optimizing for, and the picture changes once you factor in how the fish is processed, how it’s packaged, and how big the individual fish was when it was caught. The differences between tuna species are real and measurable, and a few of them might surprise you.

Mercury Across Tuna Species

Mercury is the main health concern with tuna, and it varies dramatically from one species to the next. A 2025 study analyzing commercially processed tuna found that albacore carried significantly higher total mercury concentrations than all other tuna types tested, while light tuna (typically skipjack) and skipjack both had significantly higher mercury than yellowfin.¹ That last finding catches people off guard: yellowfin, the “ahi” tuna served as steaks and sashimi, actually tested lower than chunk light cans in that dataset.

An older and widely cited analysis of canned tuna found that white-style tuna (which is almost always albacore) averaged about 0.41 parts per million of mercury, compared to roughly 0.12 ppm for light-style tuna (mostly skipjack).² That’s more than a threefold difference. Bigeye tuna rounds out the high end: large bigeye individuals caught off Brazil’s equatorial coast exceeded 1,000 nanograms per gram, surpassing legal limits for human consumption, though the species average was considerably lower.³

If you’re ranking species by mercury alone, the rough hierarchy from lowest to highest runs: skipjack, yellowfin, albacore, bigeye, and bluefin. But that hierarchy shifts depending on where the fish was caught and, critically, how big it was.

Why the Size of the Fish Matters More Than the Label

Fish accumulate mercury over their lifetimes through everything they eat, so a bigger, older tuna has had more years of bioaccumulation. Modeling work across the western and central Pacific confirmed that fish size is the single strongest factor explaining mercury variation within tuna populations, outweighing species identity in some comparisons.⁴ Physical oceanography also plays a role: tuna from regions with deeper thermoclines tend to carry higher mercury, because more methylmercury is produced in deeper, oxygen-poor water.

This matters practically because species overlap in size. A small albacore might carry less mercury than a large skipjack. And bigeye tuna showed a clear positive relationship between body weight and mercury concentration, with the biggest individuals blowing past safety thresholds while smaller ones stayed well under.³ Global review data reinforce this: tuna mercury levels track strongly with body size across oceans, and inter-species differences largely reflect the distinct feeding depths and body sizes typical of each species.⁵

For you, the takeaway is that smaller-bodied tuna species (skipjack, small yellowfin) are safer bets not because of some magical species-level protection but because they simply haven’t lived long enough or eaten enough contaminated prey to build up dangerous mercury loads.

The Selenium Factor

Mercury risk in seafood is not purely about mercury concentration. Selenium, an essential mineral, binds to mercury in the body and can blunt its toxic effects. The ratio between selenium and mercury in a given fish is arguably a better measure of safety than mercury content alone. A study of pelagic fish from the central North Pacific measured selenium-to-mercury molar ratios across tuna species and found that yellowfin came out on top among the tunas at 14.1, followed closely by skipjack at 12.8, then albacore at 5.3, and bigeye at 5.2.⁶

All four tuna species had selenium well in excess of mercury on a molar basis, meaning the selenium present could theoretically offset mercury’s harmful effects. For comparison, mako shark was the only fish in that study with a net molar excess of mercury over selenium. So even albacore, the highest-mercury tuna, still delivers a meaningful selenium buffer. That said, the gap between yellowfin and skipjack on one hand (ratios above 12) and albacore and bigeye on the other (around 5) is substantial. If you eat tuna frequently, choosing skipjack or yellowfin gives you a wider safety margin.

Canned Tuna and What “White” and “Light” Actually Mean

Most tuna consumed in the U.S. and Europe comes from cans, and the labels on those cans encode species information that isn’t always obvious. “White” tuna is almost exclusively albacore. “Light” or “chunk light” tuna is usually skipjack, though it can sometimes contain yellowfin or tongol. This distinction matters because, as noted above, white canned tuna averages roughly three to four times the mercury of light canned tuna.²

Beyond mercury, the canning process itself changes the nutritional profile of the fish. A study examining skipjack tuna subjected to different heat treatments found that canning totally destroyed EPA and DHA, the omega-3 fatty acids that make tuna nutritionally valuable in the first place. By contrast, simple cooking (steaming or boiling) preserved these fatty acids best, with microwave heating a close second. Frying was nearly as destructive as canning, with losses of about 70% for EPA and 85% for DHA.⁷ Canned tuna also picked up polyunsaturated fats from the filling oil, which inflates the total fat content but doesn’t replace the specific omega-3s that were lost.

This is a genuine trade-off. Canned tuna is convenient, shelf-stable, and affordable. But if omega-3s are your reason for eating tuna, a fresh or frozen piece that you cook gently at home delivers considerably more of them. Choosing canned tuna packed in water rather than oil at least avoids the additional lipid uptake, though it doesn’t rescue the EPA and DHA already broken down during the retort heating process.

BPA and Packaging Chemicals in Canned Tuna

Canning introduces another concern: chemical migration from the packaging material into the food. Bisphenol A (BPA), an endocrine-disrupting compound used in the epoxy linings of many metal cans, has been detected in canned tuna across multiple studies. An analysis of canned tuna sold in Lebanon found BPA in a small fraction of the samples tested.⁸ Italian market testing found at least one bisphenol compound in 83% of tuna samples packed in oil, while tuna in water (aqueous medium) showed BPA alone in about two-thirds of samples, though notably at lower levels. No bisphenols were detected in the aqueous medium itself, suggesting the migration was primarily into the fish tissue rather than the surrounding liquid.⁹

BPA exposure from canned tuna is generally considered low on a per-serving basis, but it adds to total daily BPA exposure from other canned foods, thermal receipt paper, and plastic containers. If you eat canned tuna several times a week, the cumulative load is worth thinking about. Choosing brands that use BPA-free can linings, or switching some of your tuna meals to fresh or pouch-packed options, reduces this particular exposure. Tuna in glass jars is another alternative that sidesteps the issue entirely.

Microplastics in Tuna

Microplastic contamination in fish is a relatively new area of research, and tuna isn’t exempt. A systematic review of microplastic contamination across tuna species found significant regional variation, with particularly high concentrations in bigeye tuna from the Bay of Bengal and longtail tuna from the Persian Gulf.¹⁰ Skipjack tuna caught off Indonesia’s southern Java coast also harbored microplastic particles, predominantly in filament form, along with traces of polybrominated diphenyl ethers, a class of flame retardants.¹¹ Skipjack from around India’s Lakshadweep Islands similarly showed microplastic contamination in their digestive tracts.¹²

Most microplastics in fish concentrate in the gut, which is removed during processing. The health implications of microplastics in the edible muscle tissue of tuna are still poorly understood, and no species-level recommendation exists based on microplastic load alone. What the data do show is that contamination is widespread and varies more by geography (how polluted the water is) than by species. This is a space where the science is moving fast, and the picture could look quite different in five years.

Eating Tuna Raw and the Parasite Question

Sushi-grade tuna is a different conversation from canned tuna, and it brings its own set of risks. Anisakid parasites, the nematodes responsible for anisakiasis in humans, have been found in Atlantic bluefin tuna caught off Norway. Research on adult bluefin found that the parasites typically remained attached to the stomach wall rather than penetrating it, causing ulcer-like lesions and sometimes tumor-like masses in the fish. A small number of larvae were found encapsulated on the intestine, suggesting they had penetrated thinner portions of the digestive tract.¹³

For consumers, the practical defense is straightforward: freezing tuna to specific time-temperature combinations kills anisakid larvae. The FDA recommends freezing at −20°C (−4°F) for seven days, or at −35°C (−31°F) for 15 hours. Restaurants serving sushi-grade fish are generally required to freeze it before service, though home cooks buying fresh tuna at a fish market should ask whether it’s been frozen to parasite-killing specifications. Cooking to an internal temperature of 63°C (145°F) also eliminates the risk, but that defeats the purpose if you’re eating sashimi.

Histamine and the Scombroid Risk

Tuna belongs to the scombroid family of fish, which are naturally high in the amino acid histidine. When tuna is mishandled after catching, specifically when it sits at warm temperatures for too long, certain bacteria convert histidine into histamine through an enzymatic reaction.¹⁴ Eating fish with elevated histamine causes scombroid poisoning, which looks a lot like an allergic reaction: flushing, headache, abdominal cramps, and sometimes hives or a racing heart. Symptoms usually appear within minutes to an hour of eating and resolve within a few hours, but they can be alarming.

The tricky part is that histamine is heat-stable. Once it’s formed in the flesh, cooking or canning won’t destroy it. The fish may look and smell perfectly normal. All tuna species are susceptible to histamine buildup when temperature control breaks down, so this risk doesn’t favor one species over another. What matters is the cold chain: the fish should be iced or refrigerated immediately after harvest and kept cold through every step until it reaches your plate. If you’re buying fresh tuna and it has a peppery or sharp taste, stop eating it.

Putting the Species Side by Side

Pulling together the mercury data, selenium ratios, availability, and practical considerations, here’s how the main commercial tuna species compare for regular eating:

Skipjack: Lowest mercury among commonly sold tunas, strong selenium-to-mercury ratio, the most widely available and affordable species. Dominates the canned “light” tuna market. The best all-around choice for people who eat tuna frequently.
Yellowfin: Surprisingly low mercury in several studies, and the highest selenium-to-mercury ratio of any tuna species tested. Available fresh as steaks and in some canned products. A strong option for occasional meals, especially when cooked fresh.
Albacore: Moderate to high mercury, lower selenium-to-mercury ratio than skipjack or yellowfin. Sold as “white” canned tuna and as fresh steaks. Fine in moderation but not ideal for frequent consumption, especially for pregnant women or young children.
Bigeye: High mercury, particularly in large individuals, and the lowest selenium buffer among tunas tested. Often sold as “ahi” alongside yellowfin, which can create confusion. Worth limiting or avoiding if mercury is a concern.
Bluefin: The premium sushi species, prized for its fat content. Less studied for contaminant levels in the consumer-facing literature, but its large body size and long lifespan suggest higher mercury accumulation. Parasite research confirms anisakid presence. Consumed infrequently by most people due to cost, which is probably just as well from a health standpoint.

How Cooking Method Changes the Equation

If you’re eating tuna primarily for its omega-3 content, your cooking method matters almost as much as your species choice. The hierarchy of omega-3 preservation is clear: gentle cooking methods like steaming or poaching retain EPA and DHA best, followed by microwaving. Frying and canning both cause severe losses.⁷ Frying also introduces additional fats from cooking oil, which can mask the loss on a nutrition label by raising total fat content even as the beneficial omega-3s plummet.

For canned tuna specifically, the retort process (high-temperature sterilization inside the sealed can) is what destroys omega-3s. Pouched tuna undergoes a slightly gentler thermal process and may retain somewhat more, though direct comparative data on pouched versus canned omega-3 retention are limited. If you open a can of tuna and plan to heat it again in a skillet, you’re applying a second round of heat to flesh that’s already been heavily processed, compounding the losses further. The most nutritious way to eat canned tuna is straight from the can, mixed cold into a salad or sandwich.

When Water Packing Beats Oil Packing

The filling medium inside a tuna can affects more than just taste. Tuna canned in oil absorbs fat from the filling medium during heat processing, raising its calorie density. Research on BPA migration also suggests a difference: Italian market testing found that bisphenol compounds appeared at detectable levels more frequently in oil-packed tuna than in water-packed tuna.⁹ Oil may facilitate the migration of lipophilic contaminants from the can lining into the food, though the detected amounts were still low in absolute terms.

Water-packed tuna is also lower in calories and lets you control added fat when you prepare the dish. The trade-off is texture and flavor: oil-packed tuna tends to be moister and richer tasting, and some people simply prefer it. If you’re eating tuna a couple of times a month, the packing medium is a minor detail. If it’s a staple in your weekly diet, water-packed light tuna is the cleaner choice across multiple metrics.

Fresh Tuna at the Fish Counter

Buying a fresh tuna steak gives you more control over species selection and cooking method, but it introduces other variables. Fresh tuna is highly perishable and susceptible to histamine formation if the cold chain is broken at any point between the boat and your kitchen. When buying fresh, look for flesh that is firm, moist, and free of any sharp or peppery smell. If you’re buying for raw consumption, confirm that the fish has been previously frozen to parasite-killing temperatures.

Species labeling at fish counters can be vague. “Ahi” may refer to either yellowfin or bigeye, and their mercury profiles are quite different. If the label just says “ahi tuna,” asking the fishmonger which species it is can help you make a more informed choice. Yellowfin steaks tend to be leaner and lighter in color than bigeye, which has a deeper red hue and higher fat content, but visual identification isn’t always reliable. Some specialty markets now label the species explicitly, and this is worth seeking out if you eat fresh tuna regularly.