A Head-to-Head Comparison: Salmon vs. Tuna
When it comes to seafood, both salmon and tuna are staples of a healthy diet, but they offer distinct nutritional profiles. The primary difference lies in their fat content, which directly impacts other vitamins and minerals, especially B12. Salmon is a fatty fish, while tuna is considerably leaner, particularly the canned light variety.
The B12 Winner: Salmon Takes the Lead
For a direct answer to the question, "what has more B12, tuna or salmon," the data is clear: salmon is the superior source.
- Salmon: A 3-ounce serving of cooked sockeye salmon delivers an impressive 3.8 micrograms (mcg) of vitamin B12. This amount easily exceeds the Recommended Dietary Allowance (RDA) of 2.4 mcg for the average adult.
- Tuna: A comparable 3-ounce serving of canned light tuna packed in water contains 2.5 mcg of vitamin B12. While still an excellent source that meets the daily requirement, it provides less B12 than the same serving size of salmon. It's important to note that the type of tuna matters; canned light tuna is lower in mercury than albacore or bigeye tuna.
Comparing Key Nutrients
While B12 is a significant factor, a comprehensive look at their nutritional makeup is beneficial. The table below outlines some of the most notable differences based on a 3-ounce (85g) cooked serving.
| Nutrient | Salmon (Sockeye) | Tuna (Canned Light in Water) | Key Difference |
|---|---|---|---|
| Vitamin B12 | ~3.8 mcg | ~2.5 mcg | Salmon provides significantly more B12. |
| Calories | ~133 kcal [1.2.1, calculated from 100g] | ~71 kcal [1.14.2, calculated from 1oz] | Tuna is lower in calories, especially when packed in water. |
| Total Fat | ~5.8 g [1.2.1, calculated from 100g] | ~0.7 g [1.14.2, calculated from 1oz] | Salmon is a fatty fish, containing much more fat. |
| Omega-3s (DHA/EPA) | ~1.5 g | ~0.1 g (Yellowfin) | Salmon is substantially richer in beneficial omega-3s. |
| Protein | ~22 g [1.2.1, calculated from 100g] | ~24 g [1.2.1, calculated from 100g] | Tuna offers a slightly higher protein content per serving. |
Why Vitamin B12 is So Important
Vitamin B12, or cobalamin, is a vital nutrient that the human body cannot produce. It plays a critical role in several bodily functions:
- Nerve Health: It is essential for maintaining the health of the body's nerve cells.
- Red Blood Cell Formation: B12 is necessary for the production of healthy red blood cells and for preventing a condition called megaloblastic anemia, which causes fatigue and weakness.
- DNA Synthesis: This vitamin is involved in the creation of DNA, the genetic material found in all cells.
Deficiency can lead to serious neurological and physical symptoms, including nerve damage, fatigue, and memory problems. Fish, along with meat, eggs, and dairy, is one of the best dietary sources.
Mercury Levels and Your Choice
When consuming fish, it's prudent to consider mercury content. Smaller, shorter-lived fish tend to have lower levels of mercury. The FDA categorizes fish to help consumers make informed choices:
- Salmon: Generally low in mercury and considered a "best choice," safe for consumption 2–3 times per week, even for pregnant women.
- Tuna: Mercury content varies by species. Canned light (skipjack) tuna is a "best choice," while albacore is a "good choice" with higher mercury levels and should be limited. Large tuna species like bigeye have the highest mercury content and should be avoided, particularly by pregnant women.
For those seeking a low-mercury option, salmon or canned light tuna are excellent choices. Combining them in a varied diet can help balance nutritional intake while minimizing risk.
Conclusion: Tailoring Your Choice to Your Needs
Deciding what has more B12, tuna or salmon, comes down to a clear victory for salmon. However, both fish are excellent dietary sources of this crucial nutrient. The choice depends on your broader nutritional goals: if you prioritize higher intake of B12 and omega-3 fatty acids, salmon is the better option. If your focus is on consuming more protein with lower fat and fewer calories, canned light tuna is an ideal, budget-friendly protein source. A balanced approach that includes both fish in moderation, paying attention to mercury levels in tuna, is a smart strategy for a healthy diet. For more detailed nutritional data, consult resources like the National Institutes of Health.
