Quick Answer
Eating canned tuna every day can be okay in moderation but should be limited to a few servings per week. Tuna is a good source of protein, vitamins, and minerals but also contains mercury, which can build up to unsafe levels with excessive consumption. Pregnant women, nursing mothers, and young children should especially limit canned tuna due to mercury concerns. Eating a variety of fish is recommended over eating tuna daily.
Mercury Concerns with Canned Tuna
Canned tuna contains methylmercury, a form of mercury that builds up in large fish over their lifetimes by absorbing mercury pollution in the oceans. In the human body, mercury acts as a neurotoxin, meaning it can damage the brain and nervous system with long-term exposure. Infants and young children are especially vulnerable.
The EPA and FDA recommend limiting canned tuna to:
– 6 oz per week for children
– 12 oz per week for pregnant/nursing women
– 15 oz per week for other adults
Eating tuna daily could lead to mercury exceeding these safe limits. Pregnant women are advised to completely avoid certain high mercury fish like swordfish, shark, tilefish, and bigeye tuna.
Mercury Levels in Different Tuna Varieties
Light tuna has lower mercury than white or chunk tuna:
| Type | Mercury (PPM) |
|---|---|
| Light tuna | 0.128 |
| White tuna | 0.353 |
| Chunk tuna | 0.358 |
Therefore, choosing light tuna for more frequent consumption can help reduce mercury exposure versus eating white or chunk tuna daily.
Nutrition Profile of Canned Tuna
Here are the nutrients found in a 3 ounce serving of canned light tuna in water:
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Calories | 93 | 5% |
| Protein | 20g | 40% |
| Fat | 1g | 1% |
| Sodium | 250mg | 11% |
| Vitamin A | 150 IU | 3% |
| Vitamin C | 0mg | 0% |
| Calcium | 8mg | 1% |
| Iron | 1mg | 6% |
As you can see, tuna is high in protein, providing 40% of the daily value per serving. It’s very low in fat and calories. Tuna also contains iron, vitamin A, calcium, potassium, and magnesium.
However, tuna is lacking in vitamin C and other nutrients found in fruits, vegetables, and whole grains. Relying on it as a staple could make it hard to meet all your nutritional needs.
Benefits of Tuna’s Nutrients
Here are some of the key benefits associated with the vitamins, minerals, and omega-3 fatty acids found in canned tuna:
– Protein helps build muscle, repairs tissues, and fuels the body.
– Vitamin A supports eye health and immune function.
– Iron carries oxygen in the blood to cells and helps prevent anemia.
– Omega-3 fatty acids benefit heart health and brain function.
– Selenium protects cells from damage and boosts immunity.
So tuna can be a nutritious part of a balanced diet. But it shouldn’t be the only type of fish or protein source you rely on.
Potential Downsides of Eating Canned Tuna Daily
Here are some potential downsides of building your diet around canned tuna:
1. Mercury exposure
Eating tuna every day, especially chunk white tuna, puts you at risk for excessive mercury since it bioaccumulates in the fish over time. Mercury has toxic effects on the neurological system. Intake should be limited.
2. Lacks nutrient diversity
Although tuna contains many beneficial nutrients, it lacks some vitamins and minerals that are readily available in other protein foods like chicken, beans, dairy, and plant-based foods. A tuna-heavy diet could lead to deficiencies over time.
3. Increased sodium intake
Each serving of canned tuna also contains 250+ mg of sodium, accounting for over 10% of the daily limit. Eating it daily can substantially increase sodium levels, which may raise blood pressure. Fresh tuna or homemade tuna salad has less sodium.
4. Concerns about sustainability
Some types of tuna like bluefin are overfished worldwide due to high demand. Choosing skipjack and other sustainably caught tuna helps reduce pressure on the species. But tuna populations still face threats from overfishing.
5. Risk of contaminants
In addition to mercury, tuna can also contain other pollutants like polychlorinated biphenyls (PCBs), dioxins, and pesticides that dissolve into the fat. The FDA monitors levels, but exposure could still be a concern with heavy consumption.
Healthier Ways to Eat Canned Tuna
To enjoy canned tuna more safely, here are some tips:
– Choose light tuna over white or chunk, and limit to a few servings per week
– Combine with avocado, olive oil, or nuts to offset mercury absorption
– Buy low-sodium or no salt added tuna and flavor it yourself
– Pick tuna packed in water instead of oil to reduce calories, cholesterol, and contaminants
– Serve tuna in sandwiches, salads, pasta, or tacos for more dietary variety
– Balance with other omega-3 rich seafood like salmon and sardines
– Look for sustainable fishing certification labels on cans like Marine Stewardship Council
This provides the benefits of tuna’s nutrients while limiting potential downsides of excessive consumption.
Sample Meal Plan with 2 Servings of Canned Tuna Per Week
Here is a sample weekly meal plan that includes canned tuna twice per week in healthy recipes:
| Day | Meals and Snacks |
|---|---|
| Monday | Oatmeal with berries for breakfast. Tuna salad sandwich for lunch. Roasted chicken and veggies for dinner. Mixed nuts for a snack. |
| Tuesday | Greek yogurt with granola for breakfast. Lentil soup and salad for lunch. Baked salmon with rice and asparagus for dinner. Fresh fruit for a snack. |
| Wednesday | Scrambled eggs and toast for breakfast. Tuna taco salad for lunch. Turkey meatballs with whole wheat pasta and broccoli for dinner. Low-fat string cheese for a snack. |
| Thursday | Peanut butter banana smoothie for breakfast. Chicken Caesar salad for lunch. Veggie and brown rice stir fry for dinner. Carrots and hummus for a snack. |
| Friday | Oatmeal with chia seeds for breakfast. Black bean soup and garden salad for lunch. Fish tacos with spinach and pineapple salsa for dinner. Mixed berries for a snack. |
| Saturday | Vegetable omelet for breakfast. Grilled cheese sandwich and tomato soup for lunch. Steak fajitas with peppers and onions for dinner. Plain Greek yogurt with granola for a snack. |
| Sunday | Banana protein pancakes for breakfast. Lentil and chickpea salad for lunch. Pasta with chicken sausage and broccoli for dinner. Apple with peanut butter for a snack. |
As you can see, tuna is enjoyed twice during the week lunches but balanced with a variety of other protein sources like chicken, salmon, eggs, beans and dairy. There’s plenty of fruits, veggies, whole grains, nuts and healthy fats too.
When Is Canned Tuna Unsafe to Eat?
Here are some signs that canned tuna has gone bad and is unsafe to eat:
– Bulging or leaking can, corrosion indicates bacteria growth
– Bad odor when opened, should smell fresh
– Mushy texture, should be firm and flaky
– Changes in color, should be pink/tan rather than brown or gray
– Sliminess, should not have excess liquid or grease
– Mold growth on tuna
– Past expiration date printed on can
Tuna typically lasts 3-5 years in the unopened can but only 3-4 days after opening. Properly stored, unopened canned tuna has a very long shelf life but still must be checked for signs of spoilage before eating.
How to Store Canned Tuna
To maximize freshness after opening, store tuna in a sealed container in the fridge and use within 3-4 days. Canned tuna can last 2-3 weeks in the fridge after opening if frozen in an airtight container.
Unopened canned tuna should be stored in a cool, dry pantry away from direct sunlight and heat sources. Avoid temperature extremes. For best quality, try to use canned tuna within 3 years if unopened.
Discard cans that are heavily dented, rusted, or leaking since they present a higher risk of microbial growth. Never eat from cans that spurt liquid or have an off smell when opened. Play it safe and throw away any tuna that looks or smells suspicious.
Is Eating Canned Tuna Every Day Worth the Risk?
In summary, here’s a final look at whether daily tuna is worth the risks:
Benefits
– Excellent source of protein, vitamins, minerals
– Low in calories and fat
– Convenient, affordable, and versatile ingredient
– Provides omega-3 fatty acids for heart health
Risks
– Mercury exposure can impact brain function
– Lacks nutritional variety if over-consumed
– Higher sodium than fresh tuna
– Sustainability concerns with some species
– Low levels of other contaminants possible
Conclusion
Eating canned tuna every day is probably okay if you follow a few guidelines:
– Stick to just 2-3 servings of light tuna per week
– Choose low-sodium and sustainably caught options
– Eat a variety of other fish high in omega-3s
– Maintain a diverse, balanced diet with plenty of produce
– Properly store and inspect canned tuna before eating
But it’s best to limit tuna and alternate it with other protein sources to minimize risks. Children, pregnant women and those who regularly eat seafood should be especially cautious about overdoing canned tuna intake due to mercury concerns. For most people, having tuna a couple times a week is a healthy approach.
