Fatty fish rich in omega-3 fatty acids, like salmon and anchovies, are most beneficial to heart health. But you may want to limit or avoid fish high in mercury.

Experts often recommend fish as a heart-healthy protein source. The American Heart Association (AHA) recommends having at least 2 servings of fish each week.

But not all fish are created equal when it comes to heart health. Understanding what makes a fish good for your heart — and what might make it not so good — can be key to ensuring you meet your nutritional targets.

Keep reading to learn which fish provide the most heart health benefits, what to consider when choosing, and how best to prepare them.

The AHA touts fatty fish as being particularly good for heart health. This is because fatty fish contain high amounts of omega-3 fatty acids.

Examples of fatty fish include:

Omega-3 fatty acids help your heart by regulating cholesterol, triglycerides, and blood pressure. They also help manage inflammation and oxidative stress.

Research suggests that consuming fatty fish reduces your risk of developing or dying from cardiovascular disease. A 2022 study notes that these benefits are unique to fatty fish.

Is tuna a heart-healthy fish?

People previously considered tuna a fatty fish. However, newer research shows that tuna does not have as high an omega-3 content as other fatty fish.

That doesn’t mean tuna isn’t heart-healthy. It just doesn’t give you the same levels of omega-3s as fatty fish. The AHA still recommends bluefin tuna as beneficial for your heart. It typically has a higher omega-3 content than other types of tuna.

However, tuna may also contain high amounts of mercury, which research links to a higher risk of heart disease.

While fatty fish are typically best for your heart, other fish can still offer significant benefits. Lean fish are high in protein but low in fat, especially saturated fat. They’re also typically low in calories.

Examples of lean fish include:

Some lean fish, like tilapia or catfish, may have an unfavorable omega-6 to omega-3 ratio. While this doesn’t mean they’re necessarily bad for you, research links diets with high amounts of omega-6 compared to omega-3 to a greater risk of cardiovascular disease.

While shellfish aren’t technically fish, they’re still seafood and are often a good source of omega-3 fatty acids. Examples include:

  • oysters (best)
  • mussels
  • clams
  • scallops
  • shrimp

However, shellfish may be high in cholesterol. This may not be a problem for most people, as dietary cholesterol doesn’t affect your blood cholesterol levels as much as other factors, like saturated fat. For example, a 2021 study found that people who consumed a high-shrimp diet had lower cholesterol and a lower risk of heart disease.

Still, if you need to limit your cholesterol intake, such as if you have familial hypercholesterolemia, other seafood options might serve you better.

Some types of fish contain high amounts of mercury. Mercury is one of the most harmful environmental toxins to humans. Among its many effects, mercury can increase the risk of heart disease.

The Dietary Guidelines for Americans recommend choosing fish high in omega-3s but low in mercury. Fish that are higher in the food chain are more likely to contain high amounts of mercury. Examples of fish high in mercury include:

  • tilefish
  • swordfish
  • shark
  • king mackerel
  • bigeye tuna

Even if you only consume fish with low or moderate mercury levels, you can still develop mercury poisoning if you eat too much fish.

If you’re pregnant or nursing, the Food and Drug Administration (FDA) recommends eating no more than 2 to 3 servings of fish a week.

In addition to the type of fish you buy, you may also want to consider where the fish comes from. Some fish are caught in the wild while others are farm-raised.

Farm-raised fish tend to have more fat than those caught in the wild. They may also have a lower omega-3 content and higher omega-6 content. However, farm-raised fish are less likely to have toxins and heavy metals like mercury than wild fish.

Before that fish makes its way to your plate, one final thing to consider is how you prepare and cook it.

Frying fish can add saturated and trans fats to your meal. It can even reduce the omega-3 content in fish. Experts recommend pan-frying rather than deep-frying, and using a healthy oil like olive or sunflower oil.

Lower temperature cooking methods, like steaming or braising, may be more heart-healthy options for preparing fish.

When seasoning fish, consider using pepper and simple herbs rather than basting with butter or adding too much salt. Citrus fruits like lemons can also add flavor and zest to fish.

Fish can be an important part of a heart-healthy diet. While experts recommend eating 2 to 3 servings each week, choosing the right types of fish can ensure you maximize your omega-3 to omega-6 ratio and limit your intake of toxic mercury.

For the most benefit, choose fish with high omega-3 content, such as salmon, mackerel, trout, or anchovies. Be mindful of how you prepare and cook the first, as some methods (like frying) can add unhealthy fats and remove beneficial omega-3 fatty acids.