Do I Need to Take Fish Oil if I Eat Tuna?

December 8, 2025 •

5 min read

According to the American Heart Association, adults should aim for two servings of fish per week to reap the benefits of omega-3s. For those who regularly eat tuna, the question is, do I need to take fish oil if I eat tuna, or is that enough to meet my nutritional needs?

Quick Summary

Whether you require fish oil supplements while consuming tuna depends on the tuna type, your intake frequency, and overall diet. While whole fish offers broad nutritional benefits, a targeted supplement may be necessary to meet specific EPA/DHA needs.

Key Points

Tuna Varies in Omega-3s: The omega-3 (EPA/DHA) content differs significantly between albacore (higher) and canned light/skipjack (lower) tuna, and preparation methods also impact levels.
Mercury Is a Concern with Tuna: Larger tuna species like albacore contain higher mercury levels, necessitating limits on consumption, especially for pregnant women and children.
Supplements Provide Targeted Doses: Fish oil supplements offer a consistent, measured, and typically mercury-free source of concentrated EPA and DHA, useful for filling dietary gaps.
Whole Foods Offer More Than Just Omega-3s: Eating fish provides a broader spectrum of nutrients, including protein, vitamins, and minerals, which work together for better health.
A Supplement May Be Necessary for Some: Individuals who don't eat other oily fish, have specific health conditions, or can't safely consume enough high-EPA/DHA fish due to mercury may need a supplement.
Consult a Doctor for Personalized Advice: Discussing your diet and supplement plans with a healthcare provider is crucial, particularly if you have health conditions or are on blood-thinning medication.

The Omega-3 Equation: Not All Fish Are Created Equal

Omega-3 fatty acids are essential polyunsaturated fats that play a crucial role in heart, brain, and eye health. The most beneficial types are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which are predominantly found in marine sources. While plant-based omega-3s (ALA) exist, the body's conversion to EPA and DHA is inefficient, making fish a superior dietary source.

Many people turn to tuna, a convenient and affordable protein source, to boost their omega-3 intake. However, the omega-3 content in tuna varies significantly based on the species and preparation. This variability is a key factor in determining if a supplement is needed.

Tuna's Nutritional Profile: From Albacore to Canned Light

Not all tuna provides the same omega-3 punch. Generally, fattier fish are higher in these beneficial fatty acids.

Albacore (White) Tuna: This type of tuna comes from a larger, fattier fish and contains a higher concentration of omega-3s compared to light tuna.
Light/Skipjack Tuna: Sourced from smaller fish, light tuna has significantly lower omega-3 levels. While still a good protein source, relying solely on light tuna for your omega-3s may not be enough.
Canned Tuna Preparation: The way tuna is canned also makes a difference. Tuna canned in water tends to have a more favorable omega-3 profile than tuna canned in oil, as some of the healthy fats can be lost in the draining process of oil-packed varieties.

Furthermore, for official dietary purposes in some regions, canned tuna is not classified as an 'oily fish', unlike salmon or mackerel. This distinction highlights that even with regular tuna consumption, your intake of long-chain omega-3s might still fall short of recommendations.

The Mercury Trade-Off: A Cautionary Note on Intake

One of the most significant drawbacks of relying on tuna for omega-3s is mercury contamination. Mercury is a neurotoxin that can accumulate in larger, longer-living fish.

Albacore Tuna: Due to its larger size, albacore has considerably higher mercury levels than light/skipjack tuna. Health authorities advise limiting albacore consumption to no more than one 4-ounce serving per week for most adults.
Light/Skipjack Tuna: Containing less mercury, this variety can be consumed more frequently. Still, prudent consumption limits are recommended, especially for vulnerable groups like pregnant women, who should limit total fish intake.

Because of the potential for mercury exposure, it is risky to consume enough albacore tuna to meet your omega-3 needs without exceeding safe mercury intake levels. This is where a supplement can offer a mercury-free source of EPA and DHA.

Tuna vs. Fish Oil Supplements: A Comparison


Feature	Eating Tuna	Taking Fish Oil Supplements
Source of Omega-3s	Whole food; contains a mix of nutrients.	Concentrated dose of EPA and DHA.
Omega-3 Levels (EPA/DHA)	Variable; dependent on type (Albacore > Light) and preparation.	Standardized and clearly labeled on supplement packaging.
Mercury Risk	Present, especially in Albacore. Intake must be limited.	Generally mercury-free due to purification processes.
Additional Nutrients	Provides protein, vitamins (D, B2), and minerals (iron, zinc).	Provides only omega-3s and potentially vitamins (like A and D in liver oil), but generally lacks the full nutrient profile of whole fish.
Flexibility	Limited by mercury concerns and weekly serving recommendations.	Flexible dosing allows for targeted intake to meet specific needs.
Absorption	Potentially better, as nutrients in whole foods can work synergistically.	High doses of EPA+DHA can effectively boost levels.

Factors to Consider When Making Your Choice

To determine if you need to supplement, consider these factors:

Dietary Habits: If you don't eat other oily fish like salmon, mackerel, or sardines, your omega-3 intake might be low even with tuna. Remember, the American Heart Association recommends two servings of fish per week, with one being oily, to get sufficient omega-3s.
Tuna Type and Quantity: Are you eating light canned tuna once a week? This will provide far less omega-3 than two servings of salmon. To meet EPA/DHA targets, you might need more than tuna alone can safely provide due to mercury concerns.
Health Conditions: Individuals with certain health conditions, such as heart disease or high triglycerides, may have higher omega-3 needs that can be difficult to meet through diet alone. Your doctor may prescribe or recommend a specific supplement dosage in these cases.
Life Stage: Pregnant women, breastfeeding mothers, and young children have specific requirements and should be particularly cautious about mercury intake. These groups are often advised to limit tuna and may benefit from alternative, low-mercury fish or supplements under medical guidance.
Whole Food vs. Supplement: Many health experts, including cardiologist Andrew Freeman, note that the benefits of omega-3s are most powerful when obtained from whole foods. However, supplements are a valuable tool when dietary intake is insufficient or limited by factors like mercury exposure.

Conclusion: A Personalized Approach

Eating tuna is a healthy way to get protein and some omega-3s, but it's often not enough on its own, especially with mercury limitations. To answer "Do I need to take fish oil if I eat tuna?", you must evaluate your complete diet and health goals. If you don't eat other oily fish, frequently consume lower-EPA/DHA light tuna, or have specific health needs, a fish oil supplement can effectively and safely fill the nutritional gap without the risk of high mercury intake. For specific guidance, it's always best to consult with a healthcare professional to determine your individual needs.

Your Decision-Making Guide

If you eat a variety of fatty fish (salmon, mackerel, sardines) twice a week, a fish oil supplement is likely unnecessary.
If you only eat canned light tuna occasionally, you may benefit from a supplement or incorporating other oily fish.
If you consume albacore tuna frequently, consider replacing some servings with other fish or using a supplement to lower mercury exposure.
If you are pregnant, breastfeeding, or managing a health condition, consult a doctor for personalized advice on fish and supplement intake.

Choosing the best strategy for your omega-3 needs requires balancing the benefits of whole foods with the practicality and safety of supplements. Learn more about the benefits of omega-3s from WebMD.

Frequently Asked Questions

No, according to some health guidelines, such as those from the NHS, canned tuna does not count as an oily fish, unlike salmon or mackerel. This is because the canning process affects its omega-3 content.

Albacore tuna (often labeled 'white tuna') has a higher concentration of omega-3 fatty acids than canned light tuna, which is typically made from skipjack.

Mercury levels vary by tuna type. Albacore tuna has higher mercury than light or skipjack tuna. While all fish contain some mercury, intake limits are recommended for tuna to manage exposure.

It can be difficult to get sufficient omega-3s solely from canned tuna, especially if you stick to light varieties, due to lower EPA/DHA content and mercury concerns that limit overall intake.

Fish oil supplements are generally purified to remove mercury and other contaminants found in fish. While whole fish is often preferred for its broad nutrient profile, supplements offer a targeted, cleaner source of EPA and DHA.

EPA and DHA are the types of omega-3s primarily found in fatty fish, while ALA is a plant-based omega-3. The body can convert some ALA to EPA and DHA, but the conversion rate is very low, making marine sources crucial.

Pregnant women are advised to limit or avoid certain types of tuna due to mercury risks. A mercury-free fish oil supplement may be recommended by a doctor to ensure adequate DHA intake, which is important for fetal development.