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It’s no secret that seafood is good for your heart and your brain, but you’ve probably also heard that some people should avoid certain types. This is true. If you’re allergic to seafood, you should avoid it altogether. If you’re at higher risk for foodborne illness, you should avoid certain types of seafood. However, on the whole, most people should increase their seafood intake for optimal health. Seafood nutrition can be confusing. If you’re not allergic to it and you have questions about it, this post is for you.
I’m going to cut through the confusion and tell you about some of the nutrients found in seafood (including the famous “omega-3” fats), who should avoid which types of seafood (hint: not everyone), and let you in on some pro tips on selecting the healthiest seafood. Let’s begin by summarizing the impressive health benefits of eating seafood.
Health benefits of eating seafood
Seafood is a heart- and brain-healthy food and has been linked with lower levels of inflammation and reduced risks for bone fractures, and some cancers.
When it comes to heart health, people who eat seafood as part of a nutritious dietary pattern tend to have lower risks for heart problems and have a smaller chance of dying from heart disease—even if you have a history of heart disease. For example, if you have high levels of triglycerides, eating seafood may help to lower it. Seafood may also protect your heart from rhythm disturbances, help to lower your blood pressure, and improve the function of your blood vessels. Some studies show that people who eat seafood regularly have even lower risks than those who eat it occasionally.
Eating seafood can also help to reduce the financial costs of heart disease. A 2019 study published in PLoS medicine calculated that Americans’ poor diets are responsible for an estimated $50 billion per year in health care costs associated with heart disease. The researchers found that out of the 10 dietary factors they looked at, consuming too little seafood was the second largest contributor to these staggering costs, behind consuming too few nuts and seeds.
Pro tip: Enjoy more nuts, seeds and seafood for heart health.
Seafood also helps the brain. People who eat seafood tend to have lower risks for stroke, depression and Alzheimer’s disease. Intake of seafood during pregnancy is linked with better brain and vision development in the baby. See the section below on selecting the best seafood that’s safe to eat during pregnancy.
Beyond heart and brain health, eating patterns that are higher in seafood have been linked to decreased risks of hip fractures, as well as colon and rectal cancers. These nutritious eating patterns can also decrease your risk of experiencing excess weight and obesity.
Fish and shellfish (crustaceans) are two of the top eight foodborne allergens and can cause severe and life-threatening allergic reactions (anaphylaxis) in some people. If you are seriously allergic to seafood—or any foods—the best thing is to completely avoid them and speak with a registered dietitian who can help ensure you’re getting the balanced nutrition you need.
Healthy nutrients in fish
Seafood is full of nutrients for good health including healthy fats, lean protein, vitamins and minerals.
Seafood is lower in saturated fat than red meat and is widely known for its healthy unsaturated fats called omega-3 fatty acids. Deficiency in omega-3 fatty acids is linked to heart disease, mood disorders, some cancers and arthritis. There are two main omega-3 fatty acids in seafood, including EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Seafood is the richest food source of EPA and DHA.
DHA is particularly good for your brain because it helps to keep it functioning efficiently. Your brain and nerves are partly made from fat, and they have a special preference for DHA. DHA deficiency is linked to serious cognitive problems, including Alzheimer’s disease. Consuming enough DHA regularly over the long-term is linked to improved ability to learn, improved memory and a lower risk of cognitive decline.
You can also get DHA from algae and supplements. When it comes to omega-3 supplements, recent studies show that supplementing with omega-3 fatty acids may not have the same positive impacts as eating the food itself. Eating seafood as part of a healthy dietary pattern seems to have the most health benefits, however if you don’t eat seafood, you may get some heart benefits from taking a fish oil supplement.
Seafood is also an excellent source of protein and contains essential minerals like vitamin B12, iodine, iron, selenium and zinc. It is also one of the only foods with naturally-occurring vitamin D.
Selecting the best seafood
As you now know, seafood has many nutrients and health benefits. The 2020-2025 Dietary Guidelines for Americans recommends consuming at least eight ounces (two four-ounce servings) of seafood per week. If you are pregnant or breastfeeding, you can consume up to three four-ounce servings of low-mercury seafood per week for your infant’s health. One four-ounce serving of seafood is about the size of the palm of your hand.
Some seafood contains mercury (a toxin) that can harm the brain and nervous system. Everyone is advised to try to avoid fish that are high in mercury such as shark, swordfish, marlin, orange roughy, tilefish, bigeye tuna, and king mackerel. This concern is especially important for children and anyone who is pregnant or breastfeeding.
Opt for seafood that are lower in mercury such as wild Alaskan salmon, cod, sardines, wild haddock, and non-king mackerel like Atlantic mackerel and Pacific chub mackerel. Examples of “oily” fish that contain higher amounts of omega-3 fatty acids and are also low in mercury are herring and trout.
For convenience, canned wild salmon and canned tuna are great options. Chunk light tuna is a smaller species of tuna with a lower mercury burden. But if you’re in it for the omega 3s, canned wild salmon can be swapped for tuna in your tuna salad recipes, made into salmon burgers or salmon cakes, added to egg omelets, or added to green salads.
If you’re concerned about the risks, Harvard T. H. Chan School of Public Health recommends, “the easiest way to avoid concern about contaminants is simply to eat a variety of fish and other seafood.”
Certain people should avoid eating raw seafood as they may be at higher risk for foodborne illness. This includes anyone who is pregnant, children under 5, adults over 65, and those with compromised immune systems. Raw seafood includes sushi and sashimi, raw shellfish, ceviche, seafood cooked “rare,” and smoked seafood (e.g., lox, kippered, or jerky).
When selecting fresh seafood, look for those that are properly refrigerated where the flesh looks shiny and firm, and that smell mild and not overly “fishy.” You can keep your seafood cold by picking it up toward the end of your shopping trip and ensuring it’s refrigerated as soon as you get home. If you can’t use it within two days, then wrap it up tightly and freeze it.
Pro tip: Did you know that much of the fish for sale at the seafood counter was previously frozen, not fresh? If you’re not able to eat fish purchased from the seafood counter within two days, opt to buy it frozen and thaw it yourself to allow it to be stored longer and reduce risk of food borne illness. Keeping frozen seafood on hand ensures that you have a quick-thawing, quick-cooking protein available at all times.
When it comes to cooking seafood, try to limit your intake of ones that are battered and deep-fried as they may be higher in salt and the process of deep-frying can deteriorate the healthy omega-3 fats. More healthful ways to cook seafood are to bake, broil or grill.
Enjoying seafood two to three times per week has many benefits including heart health and brain health. Plus, eating more seafood is one of the top dietary strategies for reducing health care costs from heart disease. Beyond its impressive links to heart and brain health, studies show that people who have a nutritious dietary pattern that includes seafood also have lower levels of inflammation and reduced risks of bone fractures and certain cancers.
These health benefits are because seafood is one of the best sources of omega-3 fats, and is also full of protein, vitamins and minerals.
There are a few things to look out for when choosing seafood, including looking for ones that are low in mercury and ensuring they’re fresh and properly refrigerated.
Now that you know the many health benefits of eating seafood two to three times per week, you may be wondering where to get some recipes to try. Whether you want a quick and easy introduction to preparing seafood, some gourmet inspiration, or a review of your supplement regimen, come see me in the clinic or at one of my cooking classes and check out the recipes on our website.
Baseggio Conrado, A., Patel, N., & Turner, P. J. (2021). Global patterns in anaphylaxis due to specific foods: A systematic review. The Journal of allergy and clinical immunology, 148(6), 1515–1525.e3. https://doi.org/10.1016/j.jaci.2021.03.048
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Moores, S. (2019, November 7). Pregnant safe sources of omega-3 fats. Eat Right. https://www.eatright.org/health/pregnancy/what-to-eat-when-expecting/pregnant-safe-sources-of-omega-3-fats
National heart, lung, and blood institute. (2019, December 17). Americans poor diet drives $50 billion a year in health care costs. https://www.nhlbi.nih.gov/news/2019/americans-poor-diet-drives-50-billion-year-health-care-costs
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About the Author
Lisa Markley, MS, RDN, LD
Lisa Markley, MS, RDN, LD, is an integrative dietitian culinary nutrition expert with nearly two decades of experience working towards improving the health of others. She is passionate about educating others how to harness the healing power of food and healthful lifestyle changes.