The Biggest Mistake People Make With Canned Tuna: What to Know About Mercury

Canned tuna is a convenient, affordable source of protein that can be used in sandwiches, salads, pasta dishes, and quick lunches. It also provides nutrients such as vitamin B12, selenium, and omega-3 fatty acids.

However, there is one important consideration when choosing tuna: mercury exposure depends partly on the type of tuna you eat and how often you eat it.

Social media posts sometimes claim that one simple mistake when opening a can can expose you to dangerous levels of mercury. The facts are more specific. Mercury can accumulate in fish before they are caught, and draining, rinsing, or changing the appearance of canned tuna does not reliably remove it.

Here is what you should know to enjoy canned tuna while making informed food choices.

1. Understand That Different Types of Tuna Contain Different Amounts of Mercury

Mercury occurs in the environment and can enter aquatic food chains. Fish absorb mercury as they feed, and larger predatory fish can accumulate more over time.

Not all tuna has the same mercury concentration.

According to the US Food and Drug Administration and Environmental Protection Agency, canned light tuna, which includes skipjack, generally contains less mercury than albacore or white tuna. Bigeye tuna is among the types that people who are pregnant, may become pregnant, or are breastfeeding are advised to avoid. <Cite refs={[“turn738504search1″,”turn738504search7”]}/>

When buying canned tuna, check the label to see which type you are purchasing.

2. Does Draining or Rinsing Canned Tuna Remove Mercury?

This is an important distinction.

Draining the liquid from canned tuna can reduce some of the sodium in the product, depending on the type and preparation. However, mercury is associated with the fish tissue itself.

Rinsing canned tuna is not a reliable way to remove mercury.

Instead of relying on a washing trick, choose tuna varieties with lower mercury levels and vary the types of seafood you eat.

3. How Often Can You Eat Canned Tuna?

The appropriate amount depends on the type of tuna, your overall seafood intake, and your personal circumstances.

The FDA and EPA provide specific seafood guidance for people who are pregnant, might become pregnant, are breastfeeding, and for parents choosing fish for children. Their recommendations distinguish between lower-mercury options and fish that should be limited or avoided. <Cite refs={[“turn738504search1″,”turn738504search4”]}/>

For other adults, it is sensible to vary seafood choices rather than relying on tuna every day.

Salmon, sardines, shrimp, cod, and other lower-mercury seafood options can provide variety in a balanced diet.

4. Who Should Pay Particular Attention to Mercury?

Mercury exposure is especially important during fetal and early childhood development because high exposure can harm the developing nervous system.

People who are pregnant, planning a pregnancy, or breastfeeding should follow current guidance on seafood choices. Parents and caregivers should also select age-appropriate portions and lower-mercury fish for children.

People who eat tuna very frequently may also benefit from reviewing their seafood choices to reduce repeated exposure.

5. Why Mercury in Fish Matters

The form of mercury commonly discussed in seafood is methylmercury.

At sufficiently high exposure levels, methylmercury can harm the nervous system. A developing fetus is particularly vulnerable, which is why pregnancy-related seafood guidance focuses on choosing fish with lower mercury levels.

This does not mean that all tuna is dangerous or that people should avoid all seafood. Fish provides valuable nutrients, and choosing a variety of lower-mercury options can help balance nutritional benefits with potential risks. <Cite refs={[“turn738504search0″,”turn738504search4”]}/>

6. How to Choose Canned Tuna at the Grocery Store

Use these practical tips when shopping:

Read the species label: Look for the type of tuna rather than relying only on the brand.
Choose variety: Alternate tuna with other seafood options.
Check the ingredients: Tuna packed in water and tuna packed in oil differ in texture, calories, and overall nutritional composition.
Compare sodium levels: If you are monitoring salt intake, compare nutrition labels and consider products with less sodium.
Follow storage instructions: Store unopened cans according to the label and refrigerate leftovers promptly in a suitable covered container.

Remember that a low-sodium product is not necessarily a lower-mercury product. These are separate considerations.

7. Is Canned Tuna Healthy?

Canned tuna can be part of a balanced diet.

It supplies protein and several important nutrients, and it can be a practical option for quick meals. Its nutritional value depends on the variety, ingredients, serving size, and how it fits into your overall diet.

Rather than treating tuna as either completely safe or inherently dangerous, consider the type of tuna, how frequently you eat it, and any specific dietary guidance relevant to you.

Easy Ways to Enjoy Canned Tuna

Tuna and Vegetable Salad

Combine drained tuna with chopped cucumber, tomatoes, leafy greens, and olive oil with lemon juice.

Tuna Sandwich

Mix tuna with a little plain yogurt or mayonnaise, then serve with whole-grain bread and fresh vegetables.

Tuna and Bean Bowl

Combine tuna with cooked beans, chopped vegetables, and a light dressing for a filling lunch.

Tuna Pasta

Add tuna to cooked pasta with tomatoes, herbs, and vegetables for a simple meal.

For variety, rotate these meals with dishes made from salmon, sardines, or other suitable seafood.

Frequently Asked Questions

Does rinsing canned tuna remove mercury?

Rinsing is not a reliable method for removing mercury from tuna. Mercury exposure is better managed by choosing appropriate fish varieties and varying seafood intake.

Is canned light tuna lower in mercury than white tuna?

Generally, yes. Canned light tuna, including skipjack, tends to contain less mercury than albacore or white tuna, although levels can vary. <Cite refs={[“turn738504search1″,”turn738504search7”]}/>

Can I eat canned tuna every day?

Eating tuna daily may lead to repeated mercury exposure, depending on the species and portion size. Varying your seafood choices is a sensible approach, and people in higher-risk groups should follow official recommendations.

Should pregnant women avoid all canned tuna?

Not necessarily. Official guidance distinguishes among tuna species and other seafood. Pregnant people should follow current recommendations and choose options with lower mercury levels.

Is tuna packed in water safer than tuna packed in oil?

The packing liquid mainly affects characteristics such as calories, fat content, and flavor. It does not reliably indicate the mercury level, which depends primarily on the fish itself.

Final Thoughts

Canned tuna can be a convenient and nutritious food, but the type of tuna matters when considering mercury exposure.

The most useful precaution is not a secret washing method. It is to read labels, choose lower-mercury varieties, eat a varied selection of seafood, and follow specific guidance when pregnant or feeding young children.

With informed choices, you can enjoy the nutritional benefits of seafood while taking reasonable steps to limit mercury exposure.

How do you usually eat canned tuna: in a salad, sandwich, or pasta dish? Share your favorite idea in the comments!

Medical and nutrition disclaimer: This article is for educational purposes only and does not replace individualized medical or dietary advice.