Can You Eat Tuna on a Pescatarian Diet? A Complete Guide

December 28, 2025 •

4 min read

The pescatarian diet has seen a rise in popularity, with a 2022 survey finding 4.5% of people in the UK identifying as pescatarian, a diet focused on plant-based foods with the addition of fish and seafood. This dietary approach sparks a common question: does tuna, a popular and nutritious fish, align with these principles?

Quick Summary

A pescatarian diet includes fish and seafood, so tuna is acceptable. While rich in protein and omega-3s, different tuna species vary in mercury levels and sustainability, requiring informed consumption.

Key Points

Tuna is pescatarian-friendly: As a fish, tuna is a staple food that aligns with a pescatarian diet.
Mercury levels vary by species: Different tuna types, from canned light (skipjack) to fresh bigeye, contain varying mercury concentrations, with smaller fish having less.
Moderate consumption is advised: To balance health benefits and potential mercury risks, it's recommended to consume tuna in moderation, especially higher-mercury varieties.
Rich in Omega-3s: Tuna is an excellent source of omega-3 fatty acids, essential for heart health, brain function, and reducing inflammation.
Sustainable sourcing matters: Environmental concerns like overfishing and bycatch necessitate choosing tuna from sustainable fisheries, often identified by certifications like the MSC.
Variety is important: Pescatarians should diversify their seafood intake with other low-mercury options like salmon and shrimp to maintain a balanced diet and limit exposure.

What Defines a Pescatarian Diet?

At its core, a pescatarian diet is a form of vegetarianism that incorporates fish and other seafood. The term itself is a portmanteau of the Italian word for fish, "pesce," and "vegetarian". Individuals following this diet consume fruits, vegetables, whole grains, nuts, and legumes, and also choose seafood as their primary source of animal protein, while abstaining from land animals like beef, pork, and poultry. For this reason, the dietary inclusion of tuna is, by definition, consistent with a pescatarian lifestyle. Many adopt this eating pattern for health benefits, environmental reasons, or animal welfare concerns.

Tuna: A Healthy Choice for Pescatarians

Given that a pescatarian diet embraces fish, tuna fits perfectly into this framework. Tuna is a versatile and nutritionally dense food, enjoyed in various forms, from fresh steaks to canned options. It is packed with high-quality protein, which is essential for building and repairing tissues, and is an excellent source of omega-3 fatty acids, specifically EPA and DHA. These fatty acids are renowned for their anti-inflammatory properties and their positive impact on heart health, brain function, and overall well-being. Tuna also provides a range of other essential nutrients, including B vitamins, selenium, and vitamin D. However, the acceptability of tuna within this diet extends beyond a simple 'yes.' It requires a closer look at the potential drawbacks and responsible choices.

The Realities of Mercury Levels in Tuna

For pescatarians, the main health concern regarding tuna is its mercury content. As a larger predatory fish, tuna can accumulate higher levels of mercury compared to smaller seafood. The amount of mercury varies significantly depending on the species of tuna, with larger and longer-lived species tending to have more. For example, fresh or canned albacore (white) tuna and fresh bigeye tuna have higher mercury concentrations than canned light tuna, which is typically made from skipjack. Health authorities, such as the U.S. Food and Drug Administration (FDA), provide guidance on consumption to mitigate risks, especially for vulnerable populations like pregnant women and young children.

Comparison of Tuna Types for Pescatarians


Tuna Type	Average Mercury Level	Consumption Guidance	Sustainability
Canned Light (Skipjack)	Lowest of common tuna types	"Best Choice." Safe for 2-3 servings per week.	Generally more sustainable due to smaller size and abundance.
Canned White (Albacore)	Higher than light tuna	Limit to 1 serving (6 oz) per week.	Sustainability varies; pole-caught is a better choice.
Fresh/Frozen (Yellowfin)	Higher than light tuna	Moderate consumption advised due to mercury levels.	Some stocks are overfished; check for MSC certification.
Fresh/Frozen (Bigeye)	Highest of common tuna types	Best eaten sparingly due to high mercury levels.	Often overfished; requires very cautious consumption.

Making Sustainable and Health-Conscious Choices

Beyond personal health, many pescatarians are motivated by environmental concerns, and tuna fishing presents significant issues. Problems include overfishing, illegal and unregulated fishing, and high rates of bycatch, which is the unintended capture of other marine life like dolphins, turtles, and sharks. To make an environmentally responsible choice, look for sustainable sourcing. Certifications from organizations like the Marine Stewardship Council (MSC) indicate that the tuna comes from a fishery that meets a strict set of environmental standards.

Tips for Mindful Tuna Consumption

Prioritize Low-Mercury Varieties: Opt for canned light (skipjack) tuna for more frequent consumption, reserving higher-mercury albacore for occasional treats.
Diversify Your Plate: Don't rely solely on tuna for your omega-3s. Incorporate a variety of lower-mercury seafood, such as salmon, sardines, and shrimp, to balance your nutrient intake and minimize mercury exposure.
Seek Sustainable Labels: Look for eco-certifications like the blue MSC label on seafood packaging to ensure you are supporting responsible fishing practices that protect marine ecosystems.
Stay Informed: Consult official dietary guidelines from the FDA or your local health authority for the most current recommendations on fish consumption and mercury levels. A good resource for this is the FDA's "Advice about Eating Fish" page.

Conclusion: Informed Choices are Key

For those on a pescatarian diet, tuna is a viable and nutritious option. It provides essential proteins and heart-healthy omega-3s that can significantly benefit overall health. However, its consumption comes with responsibilities, both to your own health and to the marine environment. By understanding the differences in mercury levels among tuna species and prioritizing sustainably sourced products, pescatarians can continue to enjoy this popular fish as part of a balanced and ethical diet. Making informed choices about the type and frequency of tuna consumption is the key to reaping its benefits while minimizing risks.

Visit the U.S. FDA website for up-to-date guidance on mercury levels in fish

Frequently Asked Questions

No, canned tuna varies significantly. Canned light tuna (typically skipjack) is generally lower in mercury than canned white (albacore) tuna. Health guidelines recommend limiting higher-mercury albacore consumption.

Eating tuna every day is not recommended due to mercury accumulation. Even low-mercury varieties should be consumed in moderation, as part of a varied seafood diet, to minimize health risks.

The primary health risk associated with tuna is mercury exposure. However, for most people, the health benefits of moderate fish consumption, such as omega-3s and protein, outweigh the risks, as long as mercury intake is managed responsibly.

Look for tuna products with the Marine Stewardship Council (MSC) blue label. Options caught using pole-and-line or troll methods are also considered more sustainable as they reduce bycatch compared to other methods.

Yes, a pescatarian diet includes other forms of seafood besides fish, such as shellfish like shrimp, crab, mussels, and oysters.

The main difference is the inclusion of fish and seafood. While both diets emphasize plant-based foods and exclude land animals, vegetarians also abstain from seafood, whereas pescatarians consume it.

The FDA advises that pregnant women should choose low-mercury fish. Canned light tuna is a 'best choice,' but higher-mercury albacore should be limited to one serving per week.