Is there DHA in tuna? An In-Depth Look at this Omega-3 Source

November 2, 2025 •

4 min read

Tuna is a popular seafood choice worldwide, and according to the USDA, an average 3-ounce serving of canned white tuna provides roughly 68 IUs of Vitamin D, along with other nutrients. It is also a source of omega-3 fatty acids, including DHA, an essential nutrient for brain and eye health. However, the exact amount of DHA in tuna can vary significantly depending on the species and how it is processed.

Quick Summary

Tuna does contain docosahexaenoic acid (DHA), an omega-3 fatty acid crucial for brain and eye health. The concentration varies by tuna species and preparation method, with some types offering higher levels than others, alongside other important nutrients like protein, Vitamin D, and selenium.

Key Points

Tuna is a Source of DHA: Tuna contains docosahexaenoic acid (DHA), an essential omega-3 fatty acid, alongside EPA.
DHA Varies by Tuna Type: The amount of DHA differs depending on the tuna species (e.g., albacore vs. skipjack) and preparation (canned in water or oil).
DHA Supports Brain and Eye Health: Adequate intake of DHA is critical for brain development, cognitive function, and maintaining retinal health.
Mercury Concerns Exist: Larger tuna species, like albacore, tend to have higher mercury levels, necessitating consumption limits, especially for pregnant women and young children.
Dietary Diversity is Key: Health experts recommend consuming a variety of seafood to balance omega-3 intake and manage mercury exposure risk.
Supplements are an Option: Fish oil or microalgae oil supplements offer an alternative for those with low fish intake, though whole food sources are generally preferred.

Understanding Omega-3 Fatty Acids in Tuna

Docosahexaenoic acid, or DHA, is a polyunsaturated omega-3 fatty acid that the human body cannot produce efficiently on its own and must be obtained from dietary sources. Along with eicosapentaenoic acid (EPA), another key omega-3, DHA is primarily found in marine life, such as fatty fish. Tuna, being a marine fish, is a recognized source of both EPA and DHA. These fatty acids play a critical role in cellular function throughout the body, with DHA being especially concentrated in the brain and retina of the eye. The health benefits associated with consuming adequate amounts of DHA include improved cognitive function, reduced inflammation, and better cardiovascular health.

The Importance of DHA for Brain and Eye Health

DHA is vital for both brain development in infants and the maintenance of normal brain function in adults. It is the most abundant omega-3 in the brain and is crucial for cellular membrane fluidity and neurotransmitter release. Adequate DHA intake is associated with better learning ability, memory, and may help mitigate cognitive decline associated with aging and certain mental health conditions.

For vision, DHA is a primary component of the retina's photoreceptor cells, which are responsible for vision. Healthy levels of DHA are essential for maximizing retinal function and protecting against damage caused by oxidative stress. Studies have explored DHA's potential in managing retinal diseases like retinitis pigmentosa and age-related macular degeneration (AMD).

Different Types of Tuna and Their DHA Content

The amount of DHA you get from tuna is not consistent across all varieties. Key factors influencing the omega-3 content include the species, whether it is fresh or canned, and the packing medium (water or oil).

Albacore (White) Tuna: This type of tuna, typically sold as canned "white tuna," generally has a higher fat content and, therefore, more omega-3s, including DHA, than light tuna varieties. A 3-ounce serving of albacore can contain up to 1.0 gram of combined omega-3s, which is a good source for meeting daily recommendations.
Light Tuna: Often made from skipjack or yellowfin tuna, canned light tuna has a lower fat content and consequently less DHA compared to albacore. A 3-ounce serving usually contains between 0.2 and 0.3 grams of omega-3s.
Yellowfin Tuna: Fresh yellowfin, also known as ahi tuna, provides a moderate amount of omega-3s, including both DHA and EPA. It is less fatty than bluefin but is still a valuable source of these essential fatty acids.
Bluefin Tuna: Known for its high fat content, bluefin tuna contains some of the highest levels of DHA and EPA, particularly when consumed fresh. However, due to concerns about sustainability and mercury levels, consumption is often limited.

Comparison of DHA Content in Tuna Varieties

The following table illustrates the variation in DHA levels based on the type of tuna and its preparation.


Tuna Type	DHA per 1 oz Portion	Notes
Canned Tuna in Water	56 mg	Often made with lighter species like skipjack. Lower in fat and calories than oil-packed versions, but still a source of omega-3s.
Canned Tuna in Oil	29 mg	While oil-packed tuna has higher overall fat and calories, the DHA content can vary. Some oil may be lost during processing.
Fresh Raw Tuna	25 mg	Represents the natural omega-3 content of fresh fish. Levels can differ by species.

It's important to note that the omega-3 content can be affected by the canning process, and the packing medium can influence the final nutritional profile. For example, canned tuna packed in water can sometimes contain higher DHA levels due to how the fat is retained during processing.

Risks and Dietary Recommendations

While tuna is a healthy source of omega-3s and other nutrients, the potential for mercury contamination is a significant consideration, especially for vulnerable populations such as pregnant or breastfeeding women and young children. Mercury is a neurotoxin that can accumulate in larger, older predatory fish like some tuna species.

To mitigate mercury exposure while still benefiting from DHA, experts recommend eating a variety of fish. For albacore (white) tuna, the FDA suggests limiting consumption to 6 ounces (one average meal) per week, while canned light tuna, which typically has lower mercury levels, can be consumed in larger quantities. Checking local fish advisories is also recommended.

For those who do not eat fish or need additional omega-3s, supplements derived from fish oil or algae are available. However, research suggests that the health benefits often come from the synergistic effect of consuming whole foods rather than isolated nutrients in supplements. Consulting a healthcare provider before starting any new supplement is advisable.

Combining Tuna with Other DHA Sources

A balanced diet incorporating a variety of DHA-rich foods can help ensure adequate intake. Other seafood options include salmon, mackerel, sardines, and herring, which tend to have high omega-3 content and often lower mercury levels than some larger tuna species. For non-fish sources, microalgae oil supplements provide a plant-based option for getting direct DHA. Combining different sources helps diversify nutrient intake and can help manage mercury exposure concerns.

Conclusion

Is there DHA in tuna? Yes, tuna is a good source of DHA, along with other essential nutrients like protein, Vitamin D, and selenium. However, the specific amount of DHA varies based on the tuna species and whether it's canned in water or oil. While albacore tuna generally contains more DHA than light tuna, it also typically carries higher levels of mercury. A balanced approach involves including a variety of seafood, following consumption guidelines, and potentially considering a supplement if dietary intake is insufficient. This strategy allows individuals to maximize the cognitive and cardiovascular benefits of DHA while minimizing potential risks associated with mercury accumulation. Incorporating different omega-3 sources is key to a well-rounded, nutritious diet. For further reading, an excellent resource on omega-3 fatty acids and health can be found on the British Heart Foundation website.

Frequently Asked Questions

Albacore (white) tuna generally has a higher DHA content than canned light tuna, which is often made from skipjack or yellowfin. However, it's also important to note that albacore contains higher levels of mercury.

Yes, canned tuna is considered a good source of DHA and other omega-3s. The amount varies, but even light tuna provides a beneficial amount. Check the nutrition label, as the packing liquid (water vs. oil) can also impact the final omega-3 content.

Some studies suggest that canned tuna packed in water may contain higher levels of DHA because the fat is better retained during processing, though the difference can vary by brand. Oil-packed tuna has more total fat and calories.

The primary risk associated with consuming tuna is mercury exposure, as tuna can accumulate mercury from the ocean. This is especially concerning for vulnerable groups like pregnant or nursing women, who should limit their intake of higher-mercury varieties like albacore.

While there isn't a universally set daily recommended intake for DHA alone, general omega-3 recommendations suggest around 250-500 mg of combined EPA and DHA per day for healthy adults. The specific needs can vary based on individual health status and life stage, such as during pregnancy.

DHA is vital for brain and eye health, supporting cognitive function, memory, and vision. It also has anti-inflammatory properties and supports cardiovascular health by helping to lower triglycerides and improve blood vessel function.

Most health experts recommend getting DHA from food sources like tuna whenever possible. The overall combination of nutrients in whole foods is considered more beneficial than isolated supplements. However, supplements can be a good alternative if dietary intake is insufficient.