Is it harmful to eat canned tuna every day?

October 18, 2025 •

3 min read

According to a survey cited by Consumer Reports, about one in ten U.S. adults eats canned tuna at least once a week, but is it harmful to eat canned tuna every day? While it is a convenient, budget-friendly source of protein, dietitians and health experts warn that daily consumption can lead to a buildup of mercury, a neurotoxin that can cause serious health issues over time.

Quick Summary

Daily consumption of canned tuna poses a risk due to methylmercury accumulation, particularly in larger varieties like albacore, though it also offers beneficial protein and omega-3s. Moderation is advised, with safe weekly limits varying by tuna type, and special precautions are necessary for sensitive populations like pregnant women and children.

Key Points

Mercury is the main risk: Daily canned tuna consumption can lead to a buildup of methylmercury, a neurotoxin, over time.
Not all tuna is the same: Albacore tuna generally contains higher levels of mercury than light or skipjack tuna.
Moderation is essential: Health experts and the FDA recommend consuming canned tuna in moderation, not daily, especially for varieties with higher mercury content.
Canned tuna has health benefits: It is a good source of lean protein and heart-healthy omega-3 fatty acids, but these benefits are best gained through balanced consumption.
Consider sodium and packing liquid: Many canned tuna products are high in sodium, and oil-packed versions are higher in calories, so low-sodium, water-packed options are often recommended.
Special populations need caution: Pregnant and breastfeeding women and young children are especially vulnerable to mercury's effects and should follow specific, lower consumption guidelines.

The Primary Concern: Mercury Accumulation

Methylmercury is a neurotoxin present in all fish that accumulates as larger fish consume smaller ones. Since tuna are higher on the food chain, they can contain elevated levels of mercury. Consuming canned tuna daily can lead to a buildup of mercury in the body because it's not easily eliminated. While moderate fish intake is generally beneficial for most adults, daily tuna consumption increases the risk of long-term health issues. Children and pregnant or breastfeeding individuals are especially susceptible to mercury poisoning, which can impair brain development.

Symptoms of Chronic Mercury Poisoning

Chronic mercury poisoning can manifest in various ways, primarily affecting the nervous system. This may include neurological symptoms such as peripheral vision loss, tremors, and difficulties with coordination, hearing, and speech. Some individuals experience sensory changes like tingling or 'pins and needles' sensations or alterations in taste and smell. Cognitive effects like memory loss, difficulty concentrating, and increased irritability are also linked to mercury accumulation. Long-term exposure has been associated with potential kidney damage.

Not All Canned Tuna Is Equal

The mercury content in canned tuna varies depending on the species used. This is a crucial factor for consumers balancing the health benefits of fish with potential risks.

Canned Tuna Mercury Comparison


Tuna Type	Common Species	Mercury Level (EPA Average)	FDA Consumption Advice (Adults)	Potential Health Risk (Daily)
Light Tuna	Skipjack	0.126 ppm	2-3 servings (8–12 oz) per week	Very low, if limited to recommended serving.
Albacore Tuna	Albacore	0.350 ppm	1 serving (4 oz) per week	Higher risk due to increased mercury concentration.
Bigeye Tuna	Bigeye	0.689 ppm	Avoid or consume very rarely	Very high risk; not suitable for daily or even weekly consumption.

The Nutritional Benefits of Canned Tuna

Despite mercury concerns, canned tuna is a nutritious and popular food when consumed in moderation. It is an excellent source of lean protein vital for muscle repair and satiety. Canned tuna also provides beneficial omega-3 fatty acids, which support heart, eye, and brain health. Other essential nutrients include selenium, vitamin B12, and vitamin D. For most adults, the benefits of including fish in their diet generally outweigh the risks, provided they make informed choices.

Other Considerations: Sodium and Packing Liquid

Besides mercury, the sodium content is another factor to consider with daily canned tuna intake. Many canned varieties, especially those in brine, contain added salt. High sodium intake is associated with increased blood pressure and can be risky for individuals with heart or kidney conditions. Choosing low-sodium or no-salt-added versions, or selecting tuna packed in water and draining it thoroughly, can help mitigate this.

The packing liquid also impacts nutrition. Tuna in oil has more fat and calories than tuna in water, which allows for adding healthier fats and seasonings.

Recommendations for Safe Canned Tuna Consumption

To enjoy canned tuna safely as part of your diet:

Choose light (skipjack) tuna: This type generally has lower mercury levels than albacore.
Limit frequency: Avoid eating canned tuna every day. Adhere to the FDA's recommended weekly limits, especially for tuna with higher mercury.
Vary your protein sources: Include other low-mercury fish like salmon and sardines, or other lean proteins, rather than relying solely on tuna.
Opt for low-sodium: If concerned about blood pressure, select canned tuna with minimal or no added salt.
Check labels: Look for brands that test for mercury and use responsible sourcing certifications like MSC. The FDA's "Advice about Eating Fish" guide is a helpful resource for more dietary information on fish.

Conclusion

Eating canned tuna every day is not advisable due to the potential for mercury accumulation and high sodium intake. While it offers valuable protein and omega-3s, consuming it in moderation is crucial to maximize benefits and minimize risks. By selecting lower-mercury types, diversifying your diet, and considering preparation methods, you can safely include canned tuna in a healthy lifestyle. Strict adherence to consumption guidelines is particularly important for sensitive groups like pregnant women and children to prevent developmental issues from mercury exposure. For detailed guidance on safe fish consumption, consult the {Link: FDA's official advice https://www.fda.gov/food/consumers/advice-about-eating-fish}.

Frequently Asked Questions

The primary risk is the accumulation of methylmercury, a neurotoxin that can cause neurological damage over time, especially with daily consumption. High sodium content is another risk for some individuals.

Canned light tuna, which is primarily skipjack, has the lowest mercury levels compared to other varieties like albacore. This is because skipjack are smaller and younger fish.

The FDA recommends that adults limit albacore tuna to about one 4-ounce serving per week and light tuna to two to three 4-ounce servings per week.

Yes, but they should adhere to stricter guidelines. Pregnant or breastfeeding women should limit canned light tuna to two to three servings per week and avoid bigeye tuna completely. Children should also have smaller, age-appropriate portions of low-mercury options.

Canned tuna is a great source of lean protein, heart-healthy omega-3 fatty acids, selenium, and B vitamins, offering significant nutritional benefits when consumed in moderation.

You can reduce risk by choosing light (skipjack) tuna over albacore, limiting your frequency of consumption, and diversifying your protein sources with other low-mercury fish.

Tuna packed in water has a lower fat and calorie count than oil-packed versions. Opting for low-sodium or water-packed varieties can help manage sodium intake.