What's the healthiest fish? Salmon probably comes to mind, but there are other fish that are good for your body and eco-friendly, too.

Packed with protein, fish is one of the best foods you can put on your dinner plate. It's the only one that directly supplies omega-3 fatty acids, a type of polyunsaturated fat that is important for heart and brain health. Salmon, sardines, mackerel, and tuna are among the healthiest fish because they're excellent sources of omega-3s, but all fish and shellfish have some.

“There’s very solid science showing that omega-3s can help reduce inflammatory factors associated with a variety of chronic diseases, including heart disease,” says Marian Neuhouser, Ph.D., R.D., of the Fred Hutchinson Cancer Research Center in Seattle. 

There is a catch: Some fish are high in mercury, which can be toxic to the nervous system. But this means making smart choices, not cutting out fish altogether. According to the Department of Agriculture’s new Dietary Guidelines for Americans, issued in 2015, “for the majority of wild-caught and farmed species, neither the risks of mercury nor organic pollutants [toxic substances that can accumulate through the food chain] outweigh the health benefits of seafood consumption.” 

A Consumer Reports investigation found that canned tuna is a common source of mercury and should be avoided by pregnant women. Children and women who are breast-feeding or may become pregnant should stick to light varieties. White tuna, or albacore, had much higher mercury levels.

Seafood sustainability is another factor to consider when choosing fish to eat. Increased demand and lax fishing practices can lead to overfishing and can damage other possibly at-risk species that often get caught up in nets with the intended catch. The Monterey Bay Aquarium Seafood Watch lists options that are fished or farmed in ways that protect the environment.

Your best strategy is to aim for 8 ounces per week of sustainably farmed or wild-caught, low-mercury fish. Among the healthiest fish are: Atlantic mackerel, Pacific sardines, freshwater (farmed) coho salmon and wild-caught salmon (including canned), and sablefish (black cod) from Alaska.