The Iron Advantage: Why Tuna Wins
Tuna is consistently a more potent source of iron than salmon. The iron in fish, known as heme iron, is more easily absorbed by the body compared to plant-based non-heme iron. The red color of raw tuna's flesh indicates its higher iron content due to myoglobin. Cooked tuna retains this iron.
Tuna's Mineral Powerhouse
Beyond iron, tuna provides higher amounts of several other minerals than salmon. These include magnesium, phosphorus, and selenium, which support various bodily functions like metabolism and immune health. Tuna also generally surpasses salmon in zinc content.
The Healthful Fats in Salmon
In terms of healthy fats, salmon is superior to tuna. As an oily fish, salmon is rich in omega-3 fatty acids (EPA and DHA), essential for heart and brain health. Wild-caught salmon often has a better omega-3 profile than farmed salmon. Omega-3s can improve heart health markers. This makes salmon excellent for cardiovascular and cognitive well-being.
Vitamin D and B12: Salmon's Edge
Salmon has a significant advantage in vitamins, especially vitamin D. This crucial vitamin, needed for bone health, immunity, and mood, is naturally present in few foods. Wild sockeye salmon offers more vitamin D per serving than tuna. Both fish are good sources of vitamin B12 for nerve function and red blood cells, but salmon is typically richer.
Fresh vs. Canned: How Processing Affects Nutrition
Processing affects nutritional profiles, though benefits remain. Canned tuna in water is lower in fat and calories than in oil. Canning may alter or increase some mineral concentrations, including iron, but usually within safe limits. Canned salmon with bones provides extra calcium, which tuna lacks.
The Mercury Factor: A Critical Consideration
Mercury content is a key difference. Mercury accumulates in larger predatory fish like tuna, which generally contain more mercury than salmon. Bigeye and Albacore tuna have higher levels than smaller species like Skipjack or Yellowfin used in canned light tuna, which is considered a "best choice" by the FDA. Salmon consistently has low mercury levels and is a safer option for frequent consumption, particularly for sensitive groups.
Comparison Table: Tuna vs. Salmon (per 100g, Cooked)
| Nutrient | Tuna (Fresh Bluefin) | Salmon (Farmed Atlantic) | Salmon (Wild Sockeye) |
|---|---|---|---|
| Calories | 130 kcal | 206 kcal | ~281 kcal |
| Protein | 29.15 g | 22.1 g | ~40 g |
| Fat | 0.59 g | 12.35 g | ~13 g |
| Omega-3s | Low | High | Higher |
| Iron | ~1.0-1.2 mg | ~0.25-0.4 mg | ~1.0 mg |
| Vitamin D | Low | High | Higher |
| Calcium | Low | Low | Higher (with bones) |
| Selenium | High | High | High |
Making the Right Choice for Your Diet
Both tuna and salmon are healthy, but the best choice depends on your nutritional needs. Tuna is better if you prioritize iron, selenium, and lean protein. Salmon is superior for omega-3s and vitamin D. Alternating between them allows you to benefit from both, especially if you manage mercury intake by choosing smaller tuna species or canned light tuna. A balanced diet with various nutrient-dense foods is key, and both fish contribute significantly. For more details on nutrient comparisons, Healthline offers a thorough breakdown.
Conclusion
While tuna is indeed higher in iron than salmon, the nutritional benefits are distributed across both. Tuna provides more iron and protein, while salmon is richer in omega-3s and vitamin D. Both are healthy dietary additions, with the optimal choice depending on individual needs, health goals, and concerns like mercury. Understanding their nutritional profiles helps in making informed dietary decisions.
