Studies suggest that eating fish is good for your brain, eye and cardiovascular health. Photo / 123rf
Eating seafood is good for your brain, eye and heart health. But 90% of US adults aren’t eating enough.
Are you eating enough seafood?
It’s full of vitamins, minerals and protein, and it’s an excellent source of omega-3 fatty acids, a critical nutrient that our bodies need but can’t produce. Studies suggest that eating fish is good for your brain, eye and cardiovascular health. Health authorities recommend that adults eat at least two servings every week, equivalent to about 225 grams.
Yet 90% of US adults eat so little seafood that they fall short of the recommendations. That’s not entirely surprising. Dietitians say that many people don’t know about the health benefits of eating seafood, or they may have concerns about the environmental impact and sustainability of commercial fishing. Some may be worried about exposure to mercury, a neurotoxin that’s found throughout the ocean and that can accumulate in fish. Others may be concerned about the costs.
The seafood landscape can also be confusing. With so many options - from shrimp to salmon to canned tuna - how do you know which ones to eat?
According to experts, the best types of seafood are those that meet three criteria:
Here’s what to know about seafood, including the healthiest types - and the ones you should reconsider and avoid altogether.
Fish is among the best sources of EPA and DHA, two omega-3 fatty acids that are known to reduce inflammation and promote brain and heart health.
“These types of fats are found in high concentrations in your brain, your eyes and your central nervous system,” said Katherine Zeratsky, a registered dietitian nutritionist at the Mayo Clinic. “They’re called essential fatty acids because we need them - and we have to get them from food.”
In 2020, a meta-analysis of studies that followed more than 900,000 people for up to 30 years found that higher fish consumption was associated with a lower risk of developing heart disease and a lower likelihood of dying from the disease. Another meta-analysis of studies involving roughly 670,000 people found that those who ate the most seafood were less likely to die prematurely from any cause. People who on average ate the equivalent of about a half a serving of fish per day (roughly two ounces) were 12% less likely to die early.
The evidence is so compelling that the American Heart Association says that eating one to two servings of seafood per week can reduce the risk of heart disease, strokes and sudden cardiac death, “especially when seafood replaces the intake of less healthy foods.”
According to health authorities, most children and adults should eat at least two servings of low-mercury seafood every week. But the serving sizes differ depending on your age.
The recommendations are slightly different for those who are pregnant or breastfeeding. They’re encouraged to eat two to three servings of low-mercury seafood weekly because the nutrients in fish - such as omega-3 fats, iodine, choline and iron - help promote the development of a baby’s brain, spinal cord and immune system.
According to dietitians and environmental experts, these are the best options:
Salmon
Both wild and farmed salmon are high in omega-3s and relatively low in toxins such as mercury and polychlorinated biphenyls (PCBs). The dietitians we spoke to said that as far as nutrition goes, both are great choices.
Farmed salmon tends to be less expensive than wild salmon. But it does have some disadvantages. Studies have found that the amount of omega-3s and mercury in farmed salmon can vary widely, in part because it depends on what the fish were fed. Some types of farmed salmon are also farmed in ways that can be detrimental to the environment.
While farmed salmon can certainly be a good choice, wild salmon is almost always the better option. “Wild salmon is a triple win because it’s high in good fats, low in mercury and sustainable,” said Sonya Lunder, the director of community science at the Natural Resources Defence Council and the author of a report on seafood consumption and mercury exposure for the Environmental Working Group.
For affordable options, look for canned wild salmon and frozen wild salmon burgers and fillets in the freezer section of your grocery store. Then try them out in quick and delicious recipes such as Creamy Salmon Pasta and Lentil Salmon Salad.
Sardines, anchovies and Atlantic mackerel
These small fish are a good choice for several reasons. Because they’re low on the food chain, they’re relatively low in mercury and other toxins (large predatory fish at the top of the food chain accumulate more contaminants). They’re high in protein and omega-3 fats. And they tend to be sustainable because they reproduce more rapidly than larger fish species, said Zeratsky at the Mayo Clinic.
Rainbow trout
A single serving of rainbow trout contains more than an entire day’s worth of vitamin D and vitamin B12, as well as large amounts of omega-3 fats, protein and minerals. It has a mild flavour that makes it easy to use in a variety of dishes. It’s also a good choice for environmental reasons.
And it’s relatively affordable. Just look for tinned rainbow trout and frozen rainbow trout fillets at your grocery store. One type of rainbow trout called steelhead actually looks and tastes a lot like salmon (and it usually costs less, too).
Mussels
Mussels are one of the unsung heroes of the seafood world. They’re packed with protein, omega-3 fats, iron, zinc and vitamin B12. They’re very low in mercury. Mussels can also be surprisingly easy to prepare.
Oysters
Oysters are chock full of omega-3 fats, vitamins and minerals, and they’re very low in mercury.
Raw oysters can carry potentially harmful bacteria. So it’s best to cook them before eating them.
Shrimp, tilapia and catfish
Shrimp, tilapia and catfish are among the most popular types of seafood consumed in America. They tend to be low in mercury and other contaminants - but they’re also quite low in omega-3 fats compared with other types of seafood.
According to Lunder, a pregnant woman would have to eat 15 to 20 servings of shrimp, tilapia or catfish per week to get the amount of omega-3 fats she needs. These types of seafood are still nutritious and good sources of protein. But they’re not nearly as good a seafood option as, say, salmon or sardines.
Tuna
One of the benefits of tuna is that it’s high in omega-3 fats. But the downside is that some varieties contain a lot of mercury.
Most of the tuna consumed in America is skipjack - a type of “light” tuna - followed by albacore tuna. Skipjack and other types of light tuna generally have less mercury than albacore. But the mercury content of light tuna can vary wildly. In 2023, Consumer Reports analysed mercury levels in many brands of canned tuna purchased at grocery stores and found that albacore tuna had on average three times as much mercury as canned light tuna. But some popular brands of light tuna had nearly as much mercury as albacore tuna.
According to Consumer Report’s safety experts, people who are pregnant should avoid eating canned tuna altogether and instead focus on consuming low-mercury fish. Other adults should consume no more than three servings of canned light tuna per week, or at most one serving of albacore tuna per week.
Children should avoid albacore tuna and stick to canned light tuna, but they should have no more than about two servings per week.
According to health authorities, the following fish are so high in mercury that you should avoid them altogether:
Plant foods aren’t good sources of EPA and DHA. But some plant foods do contain a different type of omega-3 fat called ALA, or alpha-linolenic acid.
Your body can convert ALA into EPA and DHA, but the process isn’t very efficient, which is why it’s generally best to get the latter directly from seafood if possible.
But if you can’t eat seafood, then you can get plenty of ALA from the following plant foods:
Spinach and Brussels sprouts also contain ALA, although not as much as the foods listed above. Some other foods that contain modest amounts of omega-3 fats are eggs, meat and dairy. Studies have found that organic and grass-fed versions of dairy, eggs and meat typically have more omega-3s than the conventional versions of these foods.
The NHS plans to broaden access through pilot schemes and online pharmacies.