How much tuna is too much a week?

Tuna is a popular and nutritious fish that is consumed by many people around the world. It is rich in protein, omega-3 fatty acids, vitamins, and minerals. However, tuna also contains mercury, which can build up in the body and cause health problems if consumed in large amounts or for a prolonged period of time. This raises the question – how much tuna is too much to eat in a week?

How much tuna can you safely eat per week?

According to the United States Food and Drug Administration (FDA) and Environmental Protection Agency (EPA), it is safe to eat up to 12 ounces (2 average meals) of canned and pouched tuna per week. The organizations also recommend limiting albacore (white) tuna to 6 ounces per week to reduce mercury exposure.

For tuna steak, it is recommended to eat no more than 3 to 5 ounces per week. Tuna sushi and sashimi intake should be limited to 6 ounces or less.

Pregnant women, nursing mothers, and young children should not eat more than 6 ounces (1 average meal) of canned tuna or 2 to 3 ounces of tuna steaks per week. Albacore tuna should be avoided entirely due to its high mercury levels.

Nutritional profile of tuna

Here is the nutritional value of 3 ounces (85g) of canned tuna, drained:

  • Calories: 93
  • Protein: 21.7g
  • Fat: 0.4g
  • Omega-3 fatty acids: 0.5-1g
  • Sodium: 250mg
  • Selenium: 50.4mcg (92% DV)
  • Vitamin D: 2.7mcg (14% DV)
  • Vitamin B12: 2.3mcg (96% DV)
  • Potassium: 200mg (4% DV)

As you can see, tuna is a high protein, low calorie fish that provides healthy fats, vitamins, minerals, and antioxidants. The selenium, vitamin D, B12, omega-3s, and protein make it a very nutritious choice.

However, tuna also contains mercury, a heavy metal that can be toxic when consumed in high amounts. Let’s analyze the mercury content of different tuna species.

Mercury levels in different types of tuna

The mercury content in tuna depends on the species, size, and origin. Larger and older fish tend to accumulate more mercury in their tissues. Here are the average mercury levels in different tuna varieties:

Tuna Variety Mercury Content
Skipjack (canned light) 0.144 ppm
Yellowfin 0.328 ppm
Albacore (canned white) 0.353 ppm
Bigeye 0.485 ppm
Bluefin 0.639 ppm

ppm = parts per million

As you can see, mercury levels are highest in bluefin tuna, followed by bigeye, albacore, yellowfin, and skipjack.

According to the EPA, concentrations above 0.5 ppm are considered potentially hazardous. Albacore, bigeye, and bluefin tuna often exceed this limit.

This is why the FDA recommends limiting white albacore tuna intake to 6 ounces weekly and avoiding bluefin tuna.

Why does tuna contain mercury?

Tuna and other large predatory fish absorb methylmercury as they feed on smaller fish. Methylmercury binds tightly to proteins in fish muscle and bioaccumulates up the food chain.

The older and larger the tuna, the more mercury it accumulates in tissues like muscle. As big fish eat small fish, the mercury gets more concentrated.

Surface level fish like mahi mahi and skipjack contain lower mercury levels since they do not eat as much contaminated fish. Deep diving tuna species that live longer absorb more mercury from their prey.

Health risks of mercury overexposure

Consuming high levels of methylmercury from seafood can affect the human nervous system and brain function. The groups most vulnerable are fetuses, infants, and young children. Mercury exposure in the womb can impair neurological development.

Some potential health effects of mercury toxicity include:

  • Numbness and tingling in hands, feet, and lips
  • Lack of coordination and trouble walking
  • Blurry vision and hearing loss
  • Memory problems
  • Irritability and mood swings
  • Depression and anxiety
  • Fatigue and brain fog

Very high mercury exposure can also damage kidneys, lungs, and the cardiovascular system. Adults are less vulnerable but can also suffer nerve, brain, kidney, and heart damage if exposed to extremely high amounts over a long period.

Since the developing fetus and young children are most at risk, women who are pregnant, planning pregnancy, or breastfeeding must limit tuna intake and avoid varieties with high mercury content.

Ways to reduce mercury exposure from tuna

Here are some effective ways to enjoy tuna while limiting mercury exposure:

  • Eat smaller tuna varieties like skipjack, tongol, and yellowfin
  • Limit intake of albacore and bigeye tuna
  • Avoid large, mature bluefin tuna
  • Check seafood guides to pick low mercury options
  • Consume a variety of seafood, not just tuna
  • Buy from sustainable sources like pole and line caught tuna
  • Grill, broil, or bake tuna instead of frying
  • Remove skin and extra fat before cooking

Pregnant women should completely avoid high mercury fish like shark, swordfish, tilefish, and king mackerel. Canned light tuna is a safer option in moderation.

Tuna consumption by country

Tuna consumption varies widely around the world. Some patterns by country:

Country Annual Tuna Consumption
Maldives 90.8 lbs per capita
Spain 7.93 lbs per capita
Italy 7.37 lbs per capita
Japan 7.34 lbs per capita
United States 2.7 lbs per capita
Russia 0.97 lbs per capita
China 0.88 lbs per capita
India 0.22 lbs per capita

The Maldives consumes the most tuna per person, followed by countries like Spain, Italy, Japan, and South Korea where tuna is an integral part of the cuisine.

In the US, tuna consumption has decreased in recent years over mercury concerns but canned tuna remains popular.

Asian nations like China and India do not have a strong cultural history of eating tuna. But demand has risen with increasing affluence and westernization of diets.

Environmental concerns with high tuna consumption

The growing global appetite for tuna raises environmental worries. Some tuna species like Atlantic bluefin are overfished and at risk of extinction. Population of other tuna like bigeye and albacore are now declining.

Longline fishing methods applied to catch tuna also threaten other marine species like sharks, turtles and seabirds that get caught as bycatch.

And fishing vessels chasing declining tuna populations burn large amounts of fuel that adds to ocean pollution.

However, tuna sourced from sustainable fisheries like those using pole and line or trolling can lower environmental impact. Choosing canned options like skipjack from approved fisheries is an eco-friendly choice.

Healthier ways to get omega-3s

While tuna offers omega-3 fatty acids, people worried about mercury can get these heart healthy fats from other sources like:

  • Salmon
  • Sardines
  • Herring
  • Mackerel (Atlantic)
  • Trout
  • Flaxseeds
  • Chia seeds
  • Walnuts
  • Soybeans
  • Fortified foods (eggs, yogurt, etc)
  • Fish oil supplements (after consulting doctor)

Salmon, sardines, trout and Atlantic mackerel have low mercury levels compared to tuna. Vegans can get omega-3s from plant sources like flax, chia, walnuts, and soy. Fortified dairy and eggs are also options.

With heart disease being a top killer, getting adequate omega-3s is important. But tuna should be balanced with above choices to limit frequent mercury exposure.

Fish with more selenium than tuna

Tuna contains selenium, a vital mineral and antioxidant. But other seafood options offer equal or higher amounts:

Fish Selenium per 3 ounces
Yellowfin tuna 50.4 mcg
Skipjack tuna 47.1 mcg
Halibut 56.6 mcg
Snapper 55.5 mcg
Cod 51.4 mcg
Mahi mahi 50.5 mcg
Salmon 49.5 mcg
Sardines 45.5 mcg

So those looking to limit tuna can still get high selenium from fish like salmon, sardines, snapper, halibut, and cod.

Healthy ways to prepare tuna

To reduce exposure to toxins and get the most nutrition from tuna:

  • Choose skipjack, tongol or yellowfin tuna
  • Remove skin and dark fatty parts
  • Grill, broil, bake or poach – avoid frying
  • Flavor with herbs, spices, citrus instead of salt
  • Make tuna salad with Greek yogurt instead of mayo
  • Use tuna in moderation as part of a varied seafood intake

Marinating tuna in acidic ingredients like lemon, lime, vinegar, or wine helps break down mercury in fish. Combining it with onions, garlic, and olive oil can also limit absorption of toxins.

Tuna recipes

Here are some delicious, healthy recipes to enjoy tuna fish in moderation:

1. Classic Tuna Salad


  • 2 (5 oz) cans tuna packed in water, drained
  • 1⁄4 cup Greek yogurt
  • 1 tbsp lemon juice
  • 2 tbsp diced onion
  • 1⁄4 cup diced celery
  • 1⁄4 cup diced cucumber
  • 1 tbsp fresh dill, chopped
  • Salt and pepper to taste


  1. In a bowl, mix together tuna, yogurt, lemon juice, onions, celery, cucumber, dill, salt and pepper.
  2. Let chill for 30 minutes in the refrigerator to allow flavors to blend.
  3. Serve on bread, lettuce leaves or crackers.

2. Seared Ahi Tuna


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