Coho salmon is one of the healthiest proteins you can eat. A 100-gram serving of raw wild coho delivers 146 calories, nearly 22 grams of protein, and just under 6 grams of total fat, most of it the omega-3 type your body can’t make on its own. It’s also remarkably low in mercury, making it a safe choice for frequent consumption.
Omega-3 Fatty Acids in Coho Salmon
The standout nutrient in coho salmon is its omega-3 fat content. Per 100 grams of raw coho, you get about 180 milligrams of EPA and 1,380 milligrams of DHA. These are the two omega-3 forms your body actually uses (as opposed to the plant-based form found in flaxseed or walnuts, which your body converts inefficiently). DHA is critical for brain cell membranes and nervous system function, while EPA plays a central role in controlling inflammation throughout the body.
The American Heart Association recommends eating two servings of fatty fish per week, with a serving being about 3 ounces cooked. Two weekly portions of coho would comfortably meet that target and provide a meaningful dose of long-chain omega-3s without the need for supplements.
Heart Health Benefits
Eating fatty fish like coho at least once a week is linked to a 50% reduction in the risk of sudden cardiac arrest. That number comes from research tracking dietary patterns alongside cardiac events over time. Additional studies show that eating fish two or more times per week reduces fatal heart attack risk in a dose-dependent way, meaning the more consistently you eat it, the greater the protection. The omega-3 fats in salmon work through several pathways at once: lowering triglycerides, reducing inflammation in blood vessels, making blood less prone to clotting, and stabilizing heart rhythm.
One important nuance: these benefits are strongest for preventing fatal cardiac events. The association with preventing non-fatal heart attacks is weaker. Still, the overall cardiovascular picture is consistently positive across decades of research.
Vitamins and Minerals
Coho salmon is an exceptional source of vitamin B12. Even a small amount of salmon protein provides well over twice the daily recommended intake, making it one of the most concentrated food sources of this vitamin. B12 is essential for nerve function and red blood cell production, and deficiency is common in older adults and people who eat little animal protein.
Selenium is another strength. A serving of coho contributes meaningfully toward your daily selenium needs. Selenium supports thyroid function and acts as a building block for your body’s own antioxidant defense systems. Coho also contains vitamin D, though in more modest amounts compared to B12 and selenium.
How Coho Compares to Other Salmon
Coho sits in a nutritional sweet spot among salmon species. King (chinook) salmon has the highest omega-3 content and the richest flavor, but it also carries more calories and more saturated fat. Sockeye is leaner with a deep red color. Coho offers a balance: solid omega-3 levels, moderate fat, and a milder flavor that tends to appeal to people who find stronger-tasting fish off-putting.
All species of wild-caught salmon are nutritionally excellent. The differences between them are relatively small compared to the gap between any salmon and, say, a typical chicken breast or ground beef. If you enjoy coho, there’s no nutritional reason to switch to a different species.
Mercury and Contaminant Levels
Coho salmon has one of the lowest mercury levels of any commercial seafood. The average concentration is just 0.044 parts per million. For context, the FDA’s action level for mercury in fish is 1.0 ppm, and high-mercury species like swordfish and king mackerel typically range from 0.7 to over 1.0 ppm. Coho is roughly 20 times lower than those fish, which is why salmon is consistently recommended as safe for pregnant women, children, and anyone else trying to limit mercury exposure.
Persistent organic pollutants like PCBs and dioxins are sometimes raised as a concern with salmon. Norwegian research comparing wild and farmed Atlantic salmon found that wild fish actually had about three times higher concentrations of dioxin-like PCBs than farmed fish, likely because wild salmon eat a more varied marine diet that accumulates these compounds. However, both wild and farmed salmon tested well below European safety limits. This is not a reason to avoid either type.
Wild vs. Farmed Coho
Wild coho has a clear advantage in one area: the proportion of omega-3 fats relative to total fat. In wild salmon, long-chain omega-3s make up about 24% of total fatty acids, compared to roughly 9% in farmed fish. Farmed salmon also has a much higher ratio of omega-6 to omega-3 fats (0.7 vs. 0.05 in wild), largely because farmed fish are fed diets containing vegetable oils. A lower omega-6 to omega-3 ratio is generally considered better for reducing chronic inflammation.
That said, farmed salmon often has more total fat, which means the absolute amount of omega-3 per serving can still be substantial. Wild coho gives you a leaner package with a better fatty acid profile. Farmed coho gives you more total fat with a less ideal ratio but still plenty of omega-3s in absolute terms. Both are far healthier choices than most other protein sources.
Sustainability Considerations
If environmental impact matters to you, U.S. wild-caught coho salmon is a strong choice. Seafood Watch rates most U.S. wild coho as a “Best Choice,” its highest sustainability tier. The one exception is coho from the Columbia River above Bonneville Dam, where populations are under more pressure. Alaskan coho, which makes up the bulk of the U.S. commercial catch, is managed with strict harvest limits and consistently rated well. Some farmed coho operations also receive good ratings, particularly land-based systems that minimize environmental contact.
Coho populations vary by region, so not all coho is equally sustainable. Checking the origin on the label or asking your fishmonger gives you a quick way to make a more informed pick.