Which is healthier salmon or mahi mahi?: A Deep Dive into Nutrition

October 9, 2025 •

4 min read

According to the American Heart Association, incorporating two servings of fatty fish like salmon per week is crucial for optimal heart health. When weighing the options, a common question arises: which is healthier salmon or mahi mahi? While both fish offer substantial health benefits, their distinct nutritional profiles cater to different dietary needs and preferences.

Quick Summary

This nutritional breakdown of salmon and mahi mahi compares their fat content, omega-3 levels, protein, vitamins, minerals, and potential contaminants like mercury to help you decide which fish best fits your health goals.

Key Points

Omega-3 Content: Salmon is significantly higher in anti-inflammatory omega-3 fatty acids (EPA and DHA), which are vital for heart and brain health.
Fat and Calories: Mahi mahi is a much leaner fish with fewer calories and less fat per serving compared to salmon.
Protein Source: Both are excellent sources of high-quality protein, but mahi mahi contains a slightly higher protein concentration per 100g.
Vitamin Profile: Salmon is a superior source of B vitamins and Vitamin D, while mahi mahi is a good source of B vitamins but offers minimal Vitamin D.
Mineral Content: Mahi mahi is richer in certain minerals like potassium, while salmon is higher in phosphorus and contains more selenium.
Mercury Levels: Salmon is considered a fish with low mercury levels, whereas mahi mahi has moderate levels, a key consideration for vulnerable groups.
Sourcing and Sustainability: The sustainability of salmon depends heavily on whether it is wild-caught or farmed, while U.S. wild-caught mahi mahi is often sustainably managed.

Understanding the differences between salmon and mahi mahi goes beyond taste. A deep dive into their nutritional composition reveals why each fish has its unique place in a healthy diet. The best choice for you ultimately depends on your specific health objectives, be it high omega-3 intake, a leaner protein source, or lower mercury exposure.

Salmon: The Omega-3 Powerhouse

Salmon is widely celebrated as an "oily fish" due to its high content of beneficial fats, especially omega-3 fatty acids. These essential fats are linked to numerous health benefits, particularly in supporting cardiovascular and cognitive function. The rich, buttery texture and distinct flavor are a result of these oils.

Key Benefits of Salmon

High in Omega-3s: Rich in EPA and DHA, omega-3s are anti-inflammatory and crucial for heart and brain health. They help to lower blood pressure, reduce triglycerides, and decrease the risk of abnormal heart rhythms.
Excellent Source of Protein: A 3.5-ounce serving of wild salmon provides around 25 grams of high-quality protein, which is essential for muscle maintenance, bone health, and overall repair.
Rich in Vitamins: Salmon is a top source of several B vitamins, including B12, B6, and Niacin. It's also one of the few natural food sources of Vitamin D, which is vital for calcium absorption and bone health.
Antioxidant Properties: The vibrant pinkish-orange color of salmon comes from astaxanthin, a powerful antioxidant that protects the body from inflammation and oxidative stress.

Potential Concerns with Salmon

Higher Calorie and Fat Count: Due to its higher fat content, salmon is more calorie-dense than mahi mahi. This may be a consideration for those focused on strict calorie control.
Wild vs. Farmed Differences: There are notable differences between wild-caught and farmed salmon. While both contain omega-3s, some studies suggest farmed salmon can have higher levels of contaminants like PCBs, though wild salmon contains slightly lower levels of mercury. The sustainability debate also differs significantly between the two, with wild salmon from well-managed fisheries often being a more sustainable choice.

Mahi Mahi: The Lean Protein Contender

Mahi mahi is a lean, white fish with a firm texture and a mild, slightly sweet flavor. Its lower fat and calorie count make it a popular choice for those looking to maximize their protein intake while minimizing fat.

Key Benefits of Mahi Mahi

Lean Protein Source: With a slightly higher protein content per 100g than salmon, mahi mahi is an excellent option for those seeking a lean protein source. A 100g serving contains approximately 23.7g of protein.
Lower in Calories and Fat: Its significantly lower fat content means fewer calories per serving, making it an ideal choice for weight management.
Good Source of Minerals: Mahi mahi is rich in important minerals like selenium, potassium, and phosphorus. Selenium is a powerful antioxidant, and potassium is crucial for blood pressure regulation.
Moderate Omega-3s: While not as rich as salmon, mahi mahi still contains a moderate amount of heart-healthy omega-3 fatty acids.

Potential Concerns with Mahi Mahi

Lower Omega-3 Content: The main trade-off for its leanness is a much lower omega-3 fatty acid content compared to salmon.
Moderate Mercury Levels: Mahi mahi has a moderate mercury concentration, higher than salmon but lower than some other popular fish like tuna or swordfish. It is important for vulnerable populations, such as pregnant women and young children, to monitor their consumption of fish with moderate mercury levels.

Salmon vs. Mahi Mahi: A Nutritional Comparison Table


Nutritional Aspect (per 100g)	Salmon (wild)	Mahi Mahi	Best For
Calories	Approx. 182 kcal	Approx. 109 kcal	Weight management
Total Fat	Approx. 8 g	Approx. 0.9 g	Lower fat intake
Omega-3s (EPA+DHA)	Very High (over 2g)	Moderate (approx. 0.24g)	Heart & brain health
Protein	Approx. 25 g	Approx. 23.7 g	Lean protein focus
Vitamin D	Excellent Source	Minimal	Vitamin D intake
Vitamin B12	Excellent Source	Good Source	B-vitamin intake
Selenium	Excellent Source	Good Source	Mineral intake
Mercury Content	Low	Moderate	Lower mercury intake

Making the Best Choice for Your Diet

Ultimately, deciding which is healthier salmon or mahi mahi? depends on your individual health priorities. If your main goal is to boost your intake of anti-inflammatory omega-3 fatty acids for cardiovascular and cognitive health, salmon is the clear winner due to its significantly higher fat content. The trade-off is more calories and fat per serving, a consideration for those on a calorie-restricted diet.

Conversely, if you're seeking a very lean protein source with fewer calories and fat, mahi mahi is an excellent choice. It still offers a good amount of protein and other key nutrients like selenium, though its omega-3 content is much lower. Those mindful of mercury intake, particularly pregnant women and young children, may prefer salmon, which has a lower concentration.

For a balanced approach, incorporating both fish into your diet can provide a wide array of nutrients. You could enjoy salmon for a nutrient-dense, omega-3-rich meal one week, and opt for lean mahi mahi the next for variety and balance. Remember to consider sourcing, choosing wild-caught options or sustainably managed fisheries where possible. The Marine Stewardship Council provides information on sustainably-sourced seafood, such as certified salmon.

Conclusion

There is no single "healthier" fish between salmon and mahi mahi; instead, there is a better fish for your specific goals. Salmon excels in omega-3s, vitamin D, and astaxanthin, making it superior for heart and brain health. Mahi mahi is the top choice for those prioritizing lean protein and lower calories. By understanding the distinct nutritional benefits and drawbacks of each, you can make the most informed decision to support your dietary needs and overall well-being. Variety, as with any healthy diet, is key. Choosing sustainably-sourced seafood, regardless of type, also ensures you are making a responsible and healthy decision for the planet.

Frequently Asked Questions

Mahi mahi is generally better for weight loss due to its lower calorie and fat content. However, salmon's healthy fats promote satiety, which can also aid in weight management.

Salmon contains significantly more omega-3 fatty acids (EPA and DHA) than mahi mahi, making it the better choice for those aiming to increase their omega-3 intake for heart and brain health.

Mahi mahi has moderate mercury levels, higher than salmon but not as high as some larger predatory fish. Vulnerable groups, like pregnant women and young children, should limit their consumption.

While both are nutritious, wild salmon can have a slightly better mineral profile, while farmed salmon often has a higher fat content, which can mean more omega-3s, but also more overall fat and calories.

Both fish are excellent protein sources, but mahi mahi is a leaner option, containing fewer calories and less fat for a comparable amount of protein.

Due to its much higher content of heart-healthy omega-3 fatty acids, salmon is generally considered superior for cardiovascular health.

Yes, incorporating both fish into your diet is an excellent strategy. This provides a broader range of nutrients and offers variety in both flavor and texture.