Eating tuna provides many health benefits, as it is a good source of protein, vitamins, and minerals. However, concerns about mercury and sustainability impact how much tuna you can safely eat. Here are some key questions answered:
Is tuna healthy?
Yes, tuna is a very healthy fish to include in your diet. A 3 ounce serving of light tuna contains:
- 116 calories
- 25 grams of protein
- Minerals like selenium, potassium, iron, and magnesium
- B vitamins like niacin, B12, and B6
- Heart healthy omega-3 fatty acids
The high protein content makes tuna helpful for building muscle, losing weight, and keeping you full. The omega-3s support brain and heart health. The potassium and B vitamins also help reduce inflammation in the body.
Why is tuna high in mercury?
Tuna and other large predatory fish absorb methylmercury from the smaller fish they eat. Methylmercury is a neurotoxin that builds up in animal tissues. The older and larger the tuna, the higher the mercury content. That’s why there are recommendations to limit intake of albacore (white) tuna which is larger.
How much tuna per week is considered safe?
Many experts recommend limiting tuna intake to no more than 2-3 servings per week to avoid dangerous mercury exposure. The EPA and FDA recommend these guidelines for tuna consumption based on mercury content:
- 2-3 servings (6 oz total) of light canned tuna per week
- 1 serving (6 oz) of albacore canned tuna per week
- 1 serving of tuna steak per week
Pregnant women, nursing mothers, and young children should not have more than 2-3 servings of light tuna per week due to greater sensitivity to mercury effects on brain development.
What are the best tuna choices?
To get the benefits of tuna while minimizing mercury risk, choose:
- Canned light tuna – Has the least mercury since it’s younger Skipjack tuna
- Wild-caught tuna – Lower in toxins than farmed fish
- Smaller tuna – Young Albacore or Yellowfin tuna have less time to accumulate mercury
- Troll/Pole caught tuna – More sustainable fishing method than nets
Avoid eating large, mature predator fish like bluefin tuna, swordfish, shark, tilefish, and king mackerel more than once a month.
Can you be allergic to tuna?
Yes, it’s possible to be allergic to tuna. Symptoms of a tuna allergy include:
- Hives, redness or swelling on the skin
- Itching or tingling around the lips, tongue, mouth or throat
- Difficulty breathing
- Runny nose
- Stomach cramps, nausea or vomiting
- Diarrhea
People with tuna allergies should avoid all fish in the same family as tuna, such as mackerel, bonito and jackfish. See an allergist for diagnosis and recommendations if you suspect a tuna allergy.
What are the benefits of tuna?
Here are some of the top health benefits tuna provides:
- High protein – Builds muscle, aids weight loss, keeps you full. Also contains all essential amino acids.
- Heart healthy fats – Omega-3s reduce inflammation, lower triglycerides and blood pressure.
- Vitamin B12 – Helps make red blood cells and DNA. Important for brain function.
- Selenium – An antioxidant that protects cells from damage and infection.
- Niacin – Helps convert food to energy. Promotes healthy skin and nerves.
- Potassium – Reduces blood pressure and water retention. Needed for muscle contractions.
- Iron – Makes hemoglobin to carry oxygen in blood. Fights anemia.
The omega-3 fats, protein, vitamin B12 and iron make tuna particularly helpful for heart health, muscle strength, energy levels and brain function.
Does tuna have mercury?
Yes, all tuna contain some mercury. However, mercury levels vary by species:
- Albacore (white) tuna – Highest mercury levels since it’s a large, mature tuna species.
- Light canned tuna – Lower mercury since it’s young Skipjack tuna.
- Fresh/frozen tuna – Mercury content varies by species and size. Check local advisories.
In general, the larger and older the tuna, the higher the mercury content since mercury accumulates over time. Pregnant women and young children are advised to choose smaller tuna species and limit intake.
Does tuna have omega-3?
Yes, tuna is one of the richest food sources of beneficial omega-3 fatty acids. A 3 ounce serving of tuna provides:
- EPA (Eicosapentaenoic acid) – 0.2 to 1 gram
- DHA (Docosahexaenoic acid) – 0.1 to 0.5 grams
EPA and DHA have powerful anti-inflammatory effects that help prevent heart disease, arthritis, diabetes, dementia and depression. Choosing fatty fish like tuna 2-3 times a week provides significant omega-3 intake.
Is tuna high in protein?
Yes, tuna is an excellent source of high quality protein. A 3 ounce serving of tuna contains about 25 grams of protein, providing over 50% of the recommended daily intake.
Some key benefits of the protein in tuna include:
- Builds muscle and strength
- Increases satiety and aids weight loss
- Slows digestion for steady energy
- Contains all essential amino acids
- Lowers inflammation
The high protein and omega-3 content of tuna makes it useful for maintaining muscle mass. Tuna is a lean protein that is low in saturated fat and calories, making it ideal for keeping a healthy weight.
Is canned tuna healthy?
Yes, canned tuna is a healthy food as long as you choose low sodium options and limit intake due to mercury concerns. Compared to fresh tuna, canned tuna:
- Is more affordable and convenient
- Has a longer shelf life
- Is a safer choice for avoiding parasites
- Contains higher amounts of omega-3s due to canning in oil
- Tends to be lower in mercury since it’s younger fish
Look for “light” canned tuna which comes from smaller, low mercury Skipjack tuna. Albacore or “white” tuna has higher mercury levels. Rinsing canned tuna reduces the sodium content.
Is raw tuna safe to eat?
Raw tuna dishes like sushi and sashimi are usually safe to eat in moderation. However, raw tuna does carry some health risks:
- Parasites – Risk of tapeworms and roundworms if fish is not properly frozen.
- Bacteria – Potential for contamination if not handled properly.
- Mercury – Larger fish like bluefin have higher mercury levels.
- Allergies – Some people may react to proteins in raw tuna.
To reduce risks, choose reputable restaurants and markets that follow freezing protocols and food safety standards. Limit high mercury fish like bluefin tuna.
Does tuna have microplastics?
Yes, tuna and other seafood contains very low levels of microplastics according to research. Microplastics are particles under 5 mm in size from degraded plastic debris. Potential health risks are still unknown.
To minimize exposure:
- Choose wild-caught tuna or tuna farmed in open nets rather than enclosed pens
- Eat smaller, younger tuna since microplastics accumulate over a lifetime
- Remove the digestive system and skin which can harbor more microplastics
- Supportreduced plastic use and improved waste management worldwide
Is tuna environmentally sustainable?
Some tuna fishing methods and species are more sustainable than others. Choosing eco-friendly tuna helps protect tuna populations and marine ecosystems. Recommendations include:
- Pole & line, troll, or handline caught tuna – No bycatch of other species
- Skipjack (light) tuna – More abundant population compared to bluefin
- Smaller sized classes – Avoid very large, mature tuna
- MSC certified – Ensures sustainable practices
- American or Canadian caught – Better managed fisheries
Avoid bluefin tuna, which is overfished and slow to mature. Supporting well-managed tuna fisheries helps ensure tuna will be around for future generations.
What are the risks of eating tuna?
Eating tuna provides many health benefits, but there are some potential downsides to consider:
- Mercury content – Limits how much tuna you can safely eat, especially higher mercury varieties like albacore tuna.
- Microplastics & toxins – Tuna contains low levels of microplastics and environmental pollutants.
- Allergies – Some people are allergic to tuna and need to avoid it.
- Unsustainable fishing – Certain tuna populations and fishing methods damage the environment.
- Sodium content – Canned tuna can be high in sodium without rinsing.
Pregnant women, children and people with sensitivities should take extra care to choose low mercury tuna and moderate portion sizes. Environmentally sustainable fishing practices also reduce health risks.
Can tuna be a healthy diet staple?
Tuna can be an important part of a healthy diet for most people when eaten in moderation and balanced with a variety of other protein sources. Two to three servings of low mercury tuna per week provides significant health benefits without going over guidelines for safe mercury exposure.
Ways to incorporate tuna in your diet include:
- Grilled or seared tuna steaks
- Salads with canned tuna
- Tuna avocado salad sandwiches
- Tuna melts
- Tuna noodle casserole
- Tuna patties or fish cakes
- Raw tuna in sushi, sashimi or poke bowls
Focus on tuna high in omega-3s but low in mercury like canned light tuna, wild-caught yellowfin and smaller albacore. Pair with plenty of vegetables, whole grains, beans, nuts and seeds for a nutrient dense, sustainable diet.
Conclusion
Tuna is a versatile, lean protein that provides many benefits including protein, vitamin B12, omega-3 fats, selenium, potassium and iron. However, issues around mercury, sustainability and allergies mean adult tuna intake should be limited to around 2-3 servings per week. Certain tuna species and sizes are safer choices than others. Eating tuna as part of a varied diet can provide great nutrition without going over guidelines for healthy and eco-friendly consumption.
Tuna Nutrition Facts
| Nutrient | Amount (in 3 oz serving) | % Daily Value |
|---|---|---|
| Calories | 116 | 6% |
| Fat | 2 grams | 3% |
| Saturated Fat | 0.4 grams | 2% |
| Protein | 25 grams | 50% |
| Omega-3 Fatty Acids | 0.5 to 1 gram | N/A |
| Sodium | 50 milligrams | 2% |
| Potassium | 250 milligrams | 7% |
| Iron | 1 milligram | 6% |
| Calcium | 6 milligrams | 1% |