From the Guidelines
Farmed salmon and wild salmon have distinct differences in their fat composition, with farmed salmon containing higher levels of total fat and a less favorable omega-3 to omega-6 ratio compared to wild salmon. The fat content in farmed salmon is roughly twice that of wild salmon, with levels around 12-16% compared to 6-8% in wild varieties 1. While both types provide beneficial omega-3 fatty acids, farmed salmon generally has higher levels of omega-6 fatty acids due to grain-based feed, resulting in a less optimal omega-3:omega-6 ratio than wild salmon. Some key points to consider about the fat composition of farmed and wild salmon include:
- Farmed salmon has similar or higher levels of omega-3 fatty acids compared to wild salmon, but the omega-3:omega-6 ratio is less favorable 1
- Wild salmon derives its omega-3s from consuming marine organisms in its natural diet, while farmed salmon's fatty acid profile directly reflects its manufactured feed
- The higher fat content in farmed salmon also means it may contain more fat-soluble contaminants like PCBs and dioxins, though levels are regulated and generally considered safe for consumption 1
- Despite these differences, both types of salmon remain nutritious protein sources rich in essential nutrients, and women who are or may become pregnant or nursing can consume 2-3 servings/week of a variety of fish lower in mercury, including salmon, while following FDA guidance 1
From the Research
Fat Composition of Farmed and Wild Salmon
- The fat composition of farmed and wild salmon differs significantly, with farmed salmon having greater levels of total lipid (average 16.6%) compared to wild salmon (average 6.4%) 2.
- The n-3 to n-6 ratio is also different, with wild salmon having a ratio of about 10 and farmed salmon having a ratio of 3-4 2.
- Farmed salmon have higher levels of omega-3 fatty acids, but also higher levels of contaminants such as polychlorinated biphenyls (PCBs), dioxins, and chlorinated pesticides 2.
Health Benefits of Omega-3 Fatty Acids
- Omega-3 fatty acids, particularly EPA and DHA, have been linked to various health benefits, including fetal development, cardiovascular function, and cognitive function 3, 4, 5, 6.
- However, the evidence for the cardiovascular benefits of omega-3 fatty acids is mixed, with some studies suggesting little or no effect on mortality or cardiovascular events 5, 6.
- Increasing intake of omega-3 fatty acids may slightly reduce the risk of coronary heart disease mortality and events, as well as reduce serum triglycerides 6.
Comparison of Farmed and Wild Salmon
- While both farmed and wild salmon are good sources of omega-3 fatty acids, the higher levels of contaminants in farmed salmon may reduce the net health benefits of consumption 2.
- Wild salmon generally has a more favorable n-3 to n-6 ratio and lower levels of contaminants, making it a potentially healthier choice 2.