Canned tuna is a versatile, nutritious and inexpensive protein source that many people enjoy regularly as part of a healthy diet. However, due to its mercury content, there are recommendations for how much tuna and other seafood to eat per week to avoid potential health risks from mercury exposure.
Quick Answer
The recommendations for canned tuna consumption per week are:
- Children aged 1-3 years: Limit to 1-2 servings or about 2-4 oz per week
- Children aged 4-7 years: Limit to 2-3 servings or about 4-6 oz per week
- Children aged 8-10 years: Limit to 3-4 servings or about 6-8 oz per week
- Children over 11 years and adults: Limit to 5-6 servings or about 10-12 oz per week
Pregnant women, nursing mothers and women trying to get pregnant should limit tuna intake to about 3-4 servings or 6-8 oz per week and avoid albacore tuna due to its higher mercury levels.
How Much Mercury Is in Canned Tuna?
Tuna and other large predatory fish accumulate mercury in their muscles and tissues from eating smaller fish over their lifetimes. When we eat tuna, we ingest the mercury as well.
Canned tuna contains small amounts of mercury, but levels can vary by species and size of fish:
- Skipjack tuna (light tuna) – Lower mercury, averages around 0.17 parts per million (ppm)
- Albacore tuna (white tuna) – Higher mercury, averages around 0.35 ppm
- Yellowfin tuna – Mercury levels around 0.31 ppm
For comparison, shark, tilefish, swordfish and king mackerel contain much higher average mercury concentrations over 1 ppm. Here are the mercury levels in canned tuna versus some other seafood for reference:
| Fish | Mercury content (ppm) |
|---|---|
| Skipjack tuna (light) | 0.17 |
| Albacore tuna (white) | 0.35 |
| Yellowfin tuna | 0.31 |
| Tilefish | 1.45 |
| Swordfish | 0.97 |
| Shark | 1.10 |
| King mackerel | 1.27 |
So tuna contains low to moderate mercury levels compared to many other fish. However, since tuna is commonly eaten in abundance, there are recommendations in place to limit exposure from frequent tuna consumption.
Mercury Exposure Recommendations
The EPA and FDA provide guidelines for how much canned tuna and other seafood can be safely eaten per week based on mercury content and potential health effects:
- Children aged 1-3 years: Limit to 1-2 servings or about 2-4 oz per week
- Children aged 4-7 years: Limit to 2-3 servings or about 4-6 oz per week
- Children aged 8-10 years: Limit to 3-4 servings or about 6-8 oz per week
- Children over 11 years and adults: Limit to 5-6 servings or about 10-12 oz per week
- Pregnant women, nursing mothers and women trying to get pregnant: Limit to about 3-4 servings or 6-8 oz per week and avoid albacore tuna which is higher in mercury
To put this into context, a standard 5 oz can of tuna is considered approximately one serving. So children aged 1-3 should eat no more than about two 5 oz cans per week, while adults can safely consume up to about five 5 oz cans per week.
These recommendations are designed to balance getting the nutritional benefits of seafood while limiting mercury exposure over time. Consuming seafood within these guidelines is considered safe for most people.
Health Risks of Mercury Exposure
The health risks associated with mercury exposure include:
- Brain and nervous system damage – Mercury is a neurotoxin that can negatively affect brain development and nerve function, especially in fetuses and young children.
- Impaired cognitive thinking – Mercury toxicity is associated with problems with memory, attention, language and fine motor and visual spatial skills.
- Kidney toxicity – High mercury intake can impact kidney function over time.
- Cardiovascular disease risk – Some research links mercury exposure to increased risk of heart disease.
- Immune system suppression – Mercury may suppress immune system function and autoimmune reactions.
Fetuses, infants and children are the most vulnerable to mercury’s toxic effects on the brain and neurological system since their bodies are still developing. Pregnant women and women trying to conceive need to be especially cautious for this reason.
Benefits of Tuna
While mercury exposure is a valid concern, canned tuna also provides important nutrients and health benefits when consumed in moderation. Here are some of the key benefits of tuna:
- High quality protein – Tuna is a lean source of protein with about 25g per 3 oz serving. Protein supports muscle growth and development.
- Omega-3 fatty acids – Tuna contains anti-inflammatory omega-3s like DHA and EPA which are good for brain and heart health.
- Vitamins and minerals – Tuna provides high amounts of selenium, vitamin D, B vitamins, magnesium and potassium.
- Convenience – Canned tuna is affordable, shelf-stable and easy to use in various recipes like salads, sandwiches and snacks.
Including tuna as part of a varied diet, while adhering to the recommended intake limits, allows you to gain its nutritional positives without excessive mercury exposure.
Ways to Reduce Mercury Intake From Tuna
There are some effective strategies you can use to reduce mercury exposure from tuna, including:
- Choose light tuna (skipjack) more often instead of albacore/white tuna since it’s lower in mercury.
- Eat a variety of fish like salmon, sardines, shrimp, pollock and cod which are all low mercury choices.
- Adhere to the recommended weekly tuna intake limits based on your age/health status.
- Avoid additional mercury sources like high fructose corn syrup and industrial pollution when possible.
- Talk to your doctor about testing your mercury levels if you eat tuna daily.
Pregnant women and parents of young children should take extra care to limit mercury exposure from fish like tuna during key developmental stages.
Signs You’re Consuming Too Much Tuna
Be aware of the following symptoms that may indicate you’re getting too much mercury from tuna and other seafood sources like sushi:
- Tingling or numbness in hands, feet, mouth
- Lack of coordination and trouble walking
- Vision changes like blurriness
- Hearing loss
- Memory problems and difficulty concentrating
- Depression, irritability, anxiety
- Frequent headaches and fatigue
If you regularly eat tuna and experience any of these symptoms, consider getting your mercury levels tested by a doctor. Switching to fish lower in mercury while limiting tuna intake may help improve symptoms if they’re linked to excess mercury.
Special Considerations for Women and Children
Pregnant and breastfeeding women are advised to completely avoid high mercury fish like swordfish, shark, tilefish and king mackerel. They should also limit albacore tuna intake to no more than 1 serving per week and stick to under 3-4 total tuna servings per week.
Young children’s brains and bodies are still developing, so limit tuna intake based on age recommendations. Avoid giving tuna to babies under 1 year old.
If you are pregnant, breastfeeding or feeding young children tuna often, discuss mercury concerns with your pediatrician or OB-GYN.
Maximum Safe Tuna Consumption
Based on the FDA and EPA’s guidelines, here are the maximum recommendations for tuna consumption per week:
| Group | Recommended Maximum Tuna Intake Per Week |
|---|---|
| Children 1-3 years | 2-4 oz or 1-2 servings |
| Children 4-7 years | 4-6 oz or 2-3 servings |
| Children 8-10 years | 6-8 oz or 3-4 servings |
| Children over 11 and adults | 10-12 oz or 5-6 servings |
| Pregnant/nursing women | 6-8 oz or 3-4 servings |
To stay within these healthy limits, carefully monitor your and your children’s canned tuna intake and emphasize low mercury fish in your seafood choices overall.
Healthy Swaps for Tuna
If you want to further reduce tuna for mercury concerns, here are some nutritious swaps to try instead:
- Salmon – Low mercury and high omega-3s. Use canned or fresh in place of tuna in salads, sandwiches, etc.
- Sardines – Low mercury small fish packed with nutrients. Use in pasta sauces, toast or salads.
- Shrimp – Low mercury shellfish that contains protein, vitamin B12 and selenium.
- Beans and lentils – Vegetarian protein sources perfect for salads, dips and veggie burgers.
- Eggs – Contain protein, healthy fats and choline. Make tuna salad with egg instead.
- Chicken or turkey – Use lean deli meat in wraps instead of tuna sandwiches.
- Lean beef – Burgers, meatballs and meatloaf make great tuna alternatives.
- Tofu – Plant-based protein can be marinated and pan-fried instead of seared tuna.
- Edamame – Soybeans pack plant protein and fiber. Toss in grain bowls and salads.
Incorporating more of these healthy plant and animal proteins can allow you to limit tuna intake while still meeting your nutrition needs.
Tuna Consumption Considerations
Here are some final tips for safely enjoying canned tuna as part of your diet:
- Check the EPA/FDA guidelines for how much tuna is safe to eat based on your age, health and pregnancy status.
- Limit albacore tuna which has more mercury than the skipjack in light tuna.
- Eat a variety of low mercury fish like salmon, tilapia and shrimp in addition to tuna.
- Talk to your doctor if you eat tuna daily and have symptoms like tingling, vision changes and memory issues.
- Have blood mercury levels tested if you regularly consume seafood high up the food chain.
- Closely monitor children’s tuna intake and choose lower mercury fish and seafood.
The Bottom Line
Tuna is a healthy protein source that is affordable and convenient for many people. However, due to its methylmercury content, there are recommendations for limiting intake based on your age and health status.
Children and pregnant women need to be especially cautious. But for most adults, enjoying light canned tuna in moderation along with a variety of other low mercury fish can allow you to safely reap the nutritional benefits.
Monitor your consumption, stick to the recommended guidelines, and balance tuna with plenty of vegetables, fruits, whole grains, nuts, seeds and plant proteins for the healthiest diet.
