Quick Answer
Eating tuna every day can provide important nutrients like protein, omega-3 fatty acids, selenium, vitamin D, and B vitamins. However, tuna also contains mercury, so eating too much can lead to mercury poisoning over time. The FDA recommends eating no more than 3-4 servings of low-mercury fish like tuna per week. Eating tuna daily long-term may also increase risk of exposure to other contaminants like PCBs. Moderation is key – including tuna as part of a balanced, varied diet with plenty of fruits and vegetables can allow you to reap the benefits of tuna without overdoing it on the mercury.
Nutritional Benefits of Tuna
High Quality Protein
Tuna is an excellent source of high quality protein. A 3 ounce serving contains about 25 grams of protein, providing over half of the recommended daily intake. Protein plays vital roles in the body including building and repairing tissues, making hormones and enzymes, and supporting a healthy immune system. Eating protein with meals and snacks helps sustain energy and keeps you feeling full between meals.
Omega-3 Fatty Acids
Tuna is one of the best food sources of omega-3 fatty acids. Omega-3s provide anti-inflammatory effects and heart health benefits like lowering triglycerides and blood pressure. They may also boost brain health. Since our bodies cannot make omega-3 fatty acids, we must get them from foods. Just one serving of tuna provides over 100% of the daily recommended intake for omega-3s.
Selenium
Tuna is an excellent source of the mineral selenium, with just 3 ounces providing over 80% of the daily recommended value. Selenium acts as an antioxidant, helps regulate thyroid hormones, and supports immune function. Very few foods naturally contain selenium.
Vitamin D
Many people are deficient in vitamin D, but just one 3 ounce serving of tuna provides over 50% of the recommended daily intake. Vitamin D works with calcium to maintain healthy bones and also supports immune function. It’s primarily obtained through sun exposure and fortified foods. Eating tuna is an easy way to boost vitamin D intake.
B Vitamins
Tuna provides several important B vitamins including niacin, B6, and B12. Niacin helps convert food into energy and promotes healthy skin and nerves. Vitamin B6 supports red blood cell production and brain development. Vitamin B12 is critical for red blood cell formation, DNA synthesis, and neurological function. A tuna steak contains up to 90% of the recommended daily intake for these essential B vitamins.
Potential Downsides of Eating Tuna Daily
Mercury Exposure
Tuna contains mercury, a heavy metal that can build up in the body over time. When mercury accumulates it can cause neurological problems and other health issues. Young children and pregnant women are most at risk. The EPA recommends limiting canned albacore (white) tuna to no more than 6 ounces per week to avoid unsafe mercury exposure. Light tuna has less mercury and the limit is 12 ounces.
Increased PCB Intake
Tuna can also contain polychlorinated biphenyls (PCBs), industrial chemicals that are toxic to the brain and nervous system. Long-term tuna consumption, especially of fatty bluefin tuna, may increase PCB build-up. High PCB levels are linked with an increased cancer risk. The FDA recommends limiting intake of high-PCB fish.
Imbalanced Nutrient Profile
While tuna is high in protein, omega-3s, selenium, and vitamin D, it is not a balanced meal on its own. Eating tuna daily could lead to excessive intake of these nutrients, while missing out on other important vitamins and minerals found in different foods. A well-rounded, diverse diet is ideal for overall health.
High Sodium Content
Canned tuna can be very high in sodium, with a 3 ounce serving containing over 300 mg. Eating tuna every day may mean going over the recommended limit for sodium, which can raise blood pressure in some individuals. Fresh and frozen tuna have much less sodium.
Contaminants
In addition to mercury and PCBs, tuna can also contain other contaminants like lead and cadmium from pollution in the oceans. Eating tuna daily for many years may increase exposure to these toxic heavy metals. Choosing lower mercury fish like salmon some of the time can help minimize this.
Lack of Variety
While tuna is healthy, eating any one food daily could lead to nutritional imbalances or food burnout over time. Varying protein sources and including different fruits, veggies, whole grains, nuts, legumes, and healthy fats is important for overall health and wellbeing.
Maximum Recommended Intake
Due to the mercury content, there are recommendations for how much tuna is safe to eat on a regular basis:
| Group | Recommendation |
| Children under 6 | No more than 1 serving light tuna per week |
| Children 6-12 years | 2 servings albacore or 4 servings light tuna per week |
| Adolescents & Adults | No more than 6 ounces albacore or 12 ounces light tuna per week |
| Pregnant & breastfeeding women | No more than 3-4 servings of low-mercury fish like tuna per week |
To stay below mercury limits, the FDA says pregnant women and young children should completely avoid eating fish that typically have the highest levels like tilefish, shark, swordfish and king mackerel.
Is Canned Tuna Healthy?
Canned tuna can be a very healthy option as it still provides the beneficial omega-3s, protein, selenium and vitamin D found in fresh tuna. However, watch out for added sodium – rinsing canned tuna before use can reduce the sodium content. Also, canned light tuna tends to be lower in mercury than albacore or white tuna. Overall, canned tuna is a shelf-stable, budget friendly option that makes it easy to incorporate tuna into your diet.
Is it Safe to Eat Tuna Every day?
Eating tuna daily is likely safe in the short term for healthy adults and children over 6 years old if mercury recommendations are followed (no more than 6oz albacore or 12oz light each week). However, try to avoid tuna every single day for months or years at a time. Occasionally alternating tuna with lower mercury seafood, beans, eggs, chicken, or other protein sources would be wise to limit long-term exposure to contaminants. Aim for a varied, balanced diet.
Tuna Nutrition Facts
Here are the nutrition facts for a 3 ounce serving of canned light tuna, according to the FDA:
| Calories | 99 |
| Protein | 22g |
| Carbs | 0g |
| Fat | 1g |
| Omega-3 Fatty Acids | 0.5-1g |
| Selenium | 76mcg |
| Sodium | 250mg |
| Vitamin D | 268IU |
| Calcium | 8mg |
| Potassium | 210mg |
As you can see, tuna is high in protein and omega-3s but low in calories, fat, carbs, and sugar. It provides excellent amounts of selenium and vitamin D as well.
Health Benefits of Eating Tuna
Here are some of the top scientifically-proven health benefits of including tuna as part of a healthy diet:
May Improve Heart Health
The omega-3 fatty acids, vitamin D, selenium, and B vitamins in tuna support cardiovascular health. Regular tuna consumption is associated with lower blood pressure, improved triglycerides, and a reduced heart disease risk. The American Heart Association recommends eating fatty fish like tuna at least twice per week.
Can Reduce Inflammation
The anti-inflammatory effects of omega-3s may help lower risk of chronic diseases tied to inflammation like heart disease, diabetes, and autoimmune conditions. Omega-3s can also ease joint swelling and stiffness from inflammatory arthritis.
May Boost Mood and Brain Function
The omega-3 DHA in tuna helps make neurotransmitters that influence mood, focus, memory and learning. Those with depression tend to have lower omega-3 levels. Eating more tuna may support brain health and mental wellbeing.
Can Support Immune Function
Many nutrients in tuna like selenium, vitamin D, zinc, and protein support proper immune system function. Tuna’s high antioxidant content also helps fight oxidative stress that can impair immunity.
May Aid Weight Management
With just 100 calories, 25g protein, and 1g fat per 3 ounce serving, tuna can be a smart choice if you’re watching your weight. The protein keeps you feeling full, while the omega-3 fats may boost metabolism. Tuna is a staple ingredient in many diet meal plans.
Can Support Bone Health
Thanks to the vitamin D, omega-3s, magnesium and other minerals it supplies, regular tuna consumption promotes strong, healthy bones by improving calcium absorption and bone mineral density. It may lower risk of osteoporosis.
May Reduce Risk of Some Cancers
Research shows an association between higher omega-3 intake and reduced risk of certain cancers including breast, colon, and prostate cancer. Selenium has also been shown to have anti-cancer effects. More research is still needed on tuna specifically.
Good Source of Vitamin B12
Tuna contains substantial amounts of vitamin B12, which plays a vital role in red blood cell formation and neurological function. Many are deficient in B12 so eating tuna regularly can help maintain healthy blood and nerve cells.
Environmentally Sustainable
Unlike some seafood like shrimp, tuna is generally fished from plentiful and well-managed stocks. Methods like “pole and line” are sustainable and prevent overfishing. Choosing tuna supports fishermen and oceans.
Potential Health Risks
There are also some potential downsides to be aware of:
Mercury Exposure
Too much tuna can lead to mercury building up and causing neurological dysfunction, especially in children and pregnant women. Follow the recommendations for safe weekly limits.
PCBs & Other Environmental Contaminants
In addition to mercury, tuna can contain other chemicals like PCBs, cadmium, lead and arsenic. Vary your protein sources and limit tuna intake to reduce this risk over the long-term.
Allergies & Histamine Intolerance
Some people are allergic to tuna. Tuna also contains high histamine levels, so those with histamine intolerance may react. Discontinue tuna if adverse symptoms develop.
May Interact with Blood Thinners
Tuna contains vitamin K, which can interfere with the effectiveness of blood thinning medications like warfarin. Those on blood thinners should keep tuna intake consistent.
Can Contain Sodium & Preservatives
Canned tuna often has added salt and preservatives like BPA. Seek lower sodium options and limit intake if concerned.
As with most good things, moderation is key. Eating tuna in place of other high-mercury fish can allow you to enjoy the benefits while minimizing any risks.
Conclusion
Eating tuna daily can certainly be healthy if you pay attention to the variety, mercury content, and portion size. Tuna supplies beneficial omega-3 fatty acids, high quality protein, vitamin D, selenium, B vitamins, and antioxidants. This nutrient profile contributes to reduced inflammation, improved heart and brain health, stronger bones and muscles, enhanced immunity, and sustained energy.
However, having too much tuna regularly over many years may increase exposure to mercury, PCBs, and other contaminants. Follow the recommendations for limiting albacore tuna due to higher mercury levels. Alternating tuna with lower mercury seafood, beans, chicken, and other protein sources is wise. Also aim for a diverse diet overall, with plenty of fruits, vegetables, whole grains, healthy fats, nuts, seeds and legumes.
Incorporating tuna into your weekly meal plan, in recommended amounts, can allow you to take advantage of the positives while avoiding negatives of overconsumption. Look for sustainable, low sodium options for the optimal health benefits from this nutrient dense fish.