Is Swordfish Bad for Your Heart? Balancing Benefits and Risks

December 7, 2025 •

3 min read

According to the American Heart Association, eating at least two servings of fish per week is recommended for heart health, yet large predatory fish like swordfish come with a high mercury warning. The question, 'Is swordfish bad for your heart?' therefore has a complex answer that requires balancing its rich nutritional profile against its potential for heavy metal contamination.

Quick Summary

This article examines the competing health factors of swordfish, specifically its beneficial omega-3 fatty acid content and the risks associated with its high mercury levels. It provides guidelines for safe consumption, outlines how to choose heart-healthy fish, and clarifies expert recommendations to help you make informed dietary choices.

Key Points

Omega-3s Benefit Heart: Swordfish is rich in omega-3 fatty acids like EPA and DHA, which are known to support heart health by lowering triglycerides and blood pressure.
High Mercury Risk: As a large predator, swordfish accumulates high levels of toxic mercury, which can offset its heart-healthy benefits.
Mercury Affects Vulnerable Groups: Pregnant women, breastfeeding mothers, and young children should avoid swordfish completely due to mercury risks.
Benefits vs. Risks: For most healthy adults, the decision involves balancing the nutritional benefits of swordfish against the potential harm from mercury.
Lower-Mercury Alternatives Exist: Fish like salmon and sardines offer high omega-3 content with far lower mercury levels, making them safer and healthier choices for regular consumption.
Moderation is Key: Occasional and moderate consumption might be acceptable for the general population, but it should not be a dietary staple.
Cooking Matters: How you prepare fish can impact its healthfulness; baking or grilling is preferable to deep-frying.
Consult a Professional: Individuals with pre-existing heart conditions should consult their doctor for personalized dietary advice.

The Heart-Healthy Upside of Swordfish

Swordfish is undeniably rich in several nutrients that support cardiovascular health. The key benefit comes from its high concentration of omega-3 fatty acids, particularly EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Omega-3s play a crucial role in maintaining heart function by lowering triglycerides, reducing blood pressure, preventing blood clots, and fighting inflammation.

Beyond omega-3s, swordfish is also a great source of selenium and vitamin D, both of which are linked to better heart health.

The Mercury Downside of Swordfish

Despite its nutritional advantages, swordfish is also one of the fish species highest in mercury due to a process called biomagnification. As a large, long-living predatory fish, it accumulates methylmercury by consuming smaller, mercury-containing fish. {Link: SeaTurtles.org https://seaturtles.org/mercury-in-fish-linked-to-heart-disease-in-men/}. Studies have found associations between high mercury levels and an increased risk of heart attacks, particularly in men.

Official Guidance on Swordfish Consumption

Concerns over mercury have prompted health organizations to issue specific advice on eating swordfish. The U.S. Food and Drug Administration (FDA) and Environmental Protection Agency (EPA) advise certain populations to avoid it entirely, including pregnant or breastfeeding women, women planning to become pregnant, and young children. For the general population, experts often recommend choosing fish varieties with lower mercury levels.

Comparison Table: Swordfish vs. Heart-Healthier Alternatives

To make an informed decision, it is helpful to compare swordfish with other popular fish options that are high in omega-3s but low in mercury. {Link: SeaTurtles.org https://seaturtles.org/mercury-in-fish-linked-to-heart-disease-in-men/}


Feature	Swordfish	Salmon	Sardines	Light Canned Tuna
Omega-3s (EPA+DHA)	High	Very High	High	Moderate
Mercury Level (µg/g average)	High (~1.00)	Very Low (~0.02)	Very Low (~0.01)	Low (~0.13)
Heart Benefits	Provides omega-3s, selenium, and vitamin D	Excellent source of omega-3s	Great source of omega-3s	Good source of omega-3s
Risk Factor	High mercury risk, especially for at-risk groups	Very low mercury risk	Very low mercury risk	Lower mercury than albacore tuna
Preparation	Can be grilled or baked	Baked, grilled, or poached	Eaten straight from can or grilled	Used in salads or sandwiches

Making the Best Choice for Your Heart

Given the information, the best strategy for heart health is to prioritize fish that offer high omega-3 content with minimal mercury contamination. Fatty fish like salmon, sardines, and mackerel are excellent choices. Eating a variety of lower-mercury seafood is the easiest way to reap the benefits while reducing exposure to contaminants. For those without specific health risks, occasional, moderate consumption of swordfish may be acceptable, but it should not be a staple.

Final Recommendations for Seafood Lovers

For more recommendations on making seafood choices for heart health, visit {Link: SeaTurtles.org https://seaturtles.org/mercury-in-fish-linked-to-heart-disease-in-men/}.

Conclusion: Navigating the Swordfish Dilemma

In conclusion, while swordfish offers heart-healthy omega-3s and other nutrients, its high mercury content poses a significant risk, particularly for vulnerable populations. This mercury can potentially counteract the benefits of omega-3s. For most individuals, especially those at higher risk, the potential harm outweighs the benefits. A heart-healthy diet is best achieved by choosing a variety of low-mercury, high-omega-3 fish like salmon or sardines. Informed choices and moderation are essential for enjoying seafood safely.

Frequently Asked Questions

For most healthy adults, occasional, moderate consumption of swordfish is generally considered acceptable, but it should not be a frequent part of your diet. Health authorities, however, advise pregnant women, breastfeeding mothers, and young children to avoid it entirely.

The primary risk is its high mercury content. Mercury is a neurotoxin that can accumulate in the body and potentially negate the heart-healthy benefits of the fish's omega-3s, posing risks particularly to the developing nervous systems of children and unborn babies.

As a large, long-lived predatory fish, swordfish is high on the food chain. This means it consumes smaller fish that contain trace amounts of mercury, causing the heavy metal to accumulate in higher concentrations in its body over time through a process called biomagnification.

Excellent heart-healthy alternatives with high omega-3s and low mercury include salmon, sardines, herring, trout, and canned light tuna. These offer similar cardiovascular benefits without the elevated mercury risk.

The American Heart Association recommends eating at least two servings of fish, especially fatty fish rich in omega-3s, per week. Choosing a variety of low-mercury options is the best strategy for consistent intake.

No, cooking methods do not significantly reduce the mercury content in fish. The mercury is bound within the fish's tissue, not on its surface.

Some studies suggest a link between high mercury exposure from fish and an increased risk of heart attacks, particularly as high mercury levels may counteract the protective effects of omega-3s.