5 Health Benefits of Fish

Fish is one of the most complete foods. It provides low-fat high-quality protein and healthy omega-3 fats. It is a great source of many vitamins and minerals.

Health benefits of fish and seafood
Table of Contents
  1. 1) Cardiovascular health
  2. 2) Mental health
  3. 3) Infant health
  4. 4) Eye health
  5. 5) Reduced autoimmune disease  
  6. How much should you eat?
  7. The healthiest fish
  8. What are the healthiest cooking methods? 
  9. What are the risks?
  10. What about raw fish? 
  11. Tips to reduce the risk of foodborne illnesses:
  12. What about fish oil supplements?
  13. Take-home message

Eating fish can improve the health of your body and mind. The research is very strong. In fact, there are thousands of studies supporting the benefits of fish. Many of the health benefits are attributed to two omega-3 fats found in fish called eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are found in fish, shellfish, seaweed, fish oil, and krill oil. These powerful fats are originally made by microalgae, which is eaten by the fish.

Your body can also make EPA and DHA from another type of omega-3 fat called alpha-linolenic acid (ALA). ALA is found in plants (nuts, seeds, green leafy vegetables). ALA can be converted to EPA and then DHA, unfortunately, the conversion is really small – less than 15%. This is why many health professionals recommend getting EPA and DHA directly from fish and/or fish oil supplements [source].

1) Cardiovascular health

Cardiovascular health has probably been studied the most. There is a lot of strong research showing 1-2 fish meals per week reduces the risk of cardiovascular disease (CVD) including congestive heart failure, coronary heart disease, sudden cardiac death, and stroke [source].

In fact, eating about 2 servings of fatty fish each week has been shown to reduce the risk of dying from heart disease by 36 percent [source]. This protective effect is especially seen when fish replaces unhealthy foods in the diet. The omega-3 fats in fish reduce many CVD risk factors, including:

  • Reducing blood pressure
  • Reducing inflammation
  • Reducing plaque forming in the arteries 
  • Reducing blood clots
  • Increased insulin sensitivity
  • Increased heart rate variability (HRV) – low HRV is associated with sudden cardiac death.

2) Mental health

Some research suggests that diets high in omega-3 fats are linked with a lowered risk of cognitive decline, dementia, and Alzheimer’s disease. High levels of DHA may help preserve brain volume. A meta-analysis study (a study that combines and analyzes results of many studies) found those with high fish intake and dietary DHA had a reduced risk of dementia and Alzheimer’s disease [source].

Fish intake is also associated with mental health. Nations that eat a lot of fish appear to have less depression. Researchers believe this is due to EPA and DHA [source]. Omega-3s have been studied and show promise in postpartum depression, attention deficit disorder, schizophrenia, and obsessive-compulsive disorder too. Researchers believe that omega-3 fats decrease depression because they reduce inflammation and free radicals, protect brain cells, support cardiovascular health, and improve insulin sensitivity. 

Although more research is needed to make recommendations regarding the amount of omega-3 fats needed, most studies have used 1-2 grams of EPA+DHA per day. To give some perspective to this, 1 gram per day would equal about three salmon meals each week [source].

3) Infant health

Mamas eat your fish. Research shows pregnant and breastfeeding women that eat 8 oz. of seafood rich in DHA have better infant health [source]. The effects are seen even after birth!  Babies born to mothers with low DHA intake had babies with lower verbal IQ at 6-18 months of age and lower prosocial behavior at age 7-8 years old [source].

If you’re pregnant or breastfeeding, it’s recommended you consume 8-12 oz. of seafood rich in omega-3s and low in mercury each week. They should limit white albacore tuna to 6 oz per week [source]. The American Academy of Pediatrics recommends breastfeeding women eat 1-2 servings of fish per week to get 200-300 mg DHA each day. This will ensure enough DHA gets in the breast milk [source].

4) Eye health

Age-related macular degeneration (AMD) can lead to vision loss in older adults.  Omega-3 fats support vision in part by reducing inflammation. Researchers believe EPA and DHA help protect the retina and prevent the development or progression of AMD [source].

Dry eyes is a chronic condition experienced by about 14% of US adults. Some research shows an improvement in dry eyes in those with high omega-3 intake. The Women’s Health Study found those consuming the most total dietary omega-3 intake had a 17% lower risk of dry eyes compared to those with the lowest intake. The benefits are likely due to reduced inflammation [source].

5) Reduced autoimmune disease  

Eating fish may protect against autoimmune diseases. An autoimmune disease occurs when the immune system mistakenly attacks healthy body tissue. Fish intake appears to positively impact several autoimmune diseases, including type 1 diabetes, rheumatoid arthritis, multiple sclerosis, and possibly inflammatory bowel disease (e.g., Crohn’s disease). 

EPA and DHA appear to be behind the protection. EPA and DHA have anti-inflammatory properties making them useful in the management of autoimmune diseases [source]. Vitamin D in fish may also provide protective effects against autoimmune disease. Studies have found a reduced risk of type 1 diabetes, rheumatoid arthritis, and multiple sclerosis in people with high vitamin D intake [source].

How much should you eat?

Recommendations vary depending on the organization and are often based on health status.

Population Recommendation
U.S. Department of Health and Human Services (source)
General population 8 ounces per week providing 250 mg per day of EPA and DHA
Pregnant and lactating women 8-12 oz. per week of seafood
Academy of Nutrition and Dietetics (source)
Adults 500 mg EPA +DHA/day
American Heart Association (source)
Adults without cardiovascular disease 2 servings (3.5 oz cooked) of fatty fish per week
Adults with cardiovascular disease 1 gram/day EPA+DHA from fatty fish
Adults with high triglycerides 2-4 gram/day EPA+DHA as capsules under physician’s care
American Psychiatric Association (source)
Adults Consume fish twice a week
Patients with mood, impulse control or psychotic disorders Fatty fish at least twice a week (1 gram/day EPA+DHA)
Patients with mood, impulse control or psychotic disorders Supplement 1-9 grams/day. >3 grams/day monitored by physician
March of Dimes (source)
Pregnant and nursing women 200 mg DHA from fish, fortified foods, or supplements

The healthiest fish

Fatty fish rich in omega-3 fats that are low in toxins are best. The table below presents fish rich in omega-3 fats [source]. A table depicting fish with the least and most toxins is found later in this article.

EPA & DHA in 3 oz. Cooked Fish/Seafood Type of Fish/Seafood
1,000 mg – 1,500 mg American shad, Anchovies, Herring (wild), Mackerel, Rainbow trout (wild or farmed), Sablefish, Salmon (canned, wild, or King. farmed), Tuna (bluefin)
500 mg – 1,000 mg Mussels, Oysters, Salmon (wild sockeye, coho, or pink), Sardines (canned), Smelt, Swordfish, Trout, Tuna (albacore)
200 mg – 500 mg Catfish (wild), Crab-king (Dungeness or snow), Flounder, Grouper (wild), Ocean perch, Pollock, Seatrout, Snapper, Tuna (canned in water)
Less than 200 mg Blue Crab (wild), Catfish (farmed), Cod (wild), Haddock (wild), Scallops (wild), Shrimp (wild), Tilapia (farmed)

What are the healthiest cooking methods? 

The nutrient profile of your fish can vary depending on the type of fish, cooking time, and the cooking method. The healthiest cooking methods to retain nutrients are baking, steaming, poaching, and even microwaving. 

Poaching and steaming are low-temperature cooking methods that may preserve healthy omega-3 fatty acids better than other methods [source]. Baking compared to frying will also help protect omega-3 fats and retain more vitamin D [source]. Microwaving fish can also help preserve nutrients because it is a fast and relatively low-temperature cooking method. In fact, several studies have found that microwaving fish can help prevent the loss of its healthy omega-3 fatty acids [source].

Grilling and broiling fish can produce some harmful compounds. If you use these methods, it is best to cook the fish for the shortest time possible and avoid charring the flesh. Frying can increase the amount of fat in your fish and might reduce vitamin D [source]. If you’re frying, pan-fry rather than deep-fry your fish, and use a healthy oil like organic extra-virgin olive oil.

What are the risks?

There is one downside to eating a lot of fish. Toxins! Unfortunately, fish may contain environmental pollutants. Large fish that live a long time contain higher levels of mercury and environmental toxins. The risks of exposure vary depending on a person’s age and health. It is especially important for kids and pregnant or nursing women to avoid eating fish high in mercury.

Higher Mercury Lower Mercury
Shark, Swordfish, Tilefish, King Mackerel Salmon, Anchovies, Herring, Sardines, Pacific Oysters, Trout, Atlantic and Pacific Mackerel

Reduce Risk. Consider limiting farm-raised fish. Some research shows these fish may contain antibiotics, pesticides, and other chemicals that can harm your health.  Exposure to toxins can also be lowered by removing the skin and surface fat before cooking. If you eat fish caught in local lakes, rivers, or coastal areas, check with local advisories about the safety. Additionally, eating a variety of fish may help reduce the adverse effects of pollutants.

Benefits outweigh the risks! The American Heart Association says the benefits outweigh the risk for most healthy adults [source]. Stay within the FDA guidelines to minimize risk – 12 oz. of fish per week in healthy adults [source].

What about raw fish? 

Sushi, sashimi, poke, and ceviche are very popular raw fish dishes. Raw fish may contain bacteria that can make you sick. You can minimize risk by eating at reputable restaurants that have properly handled and prepared the fish. Cooking reduces risk because it kills harmful bacteria.

Tips to reduce the risk of foodborne illnesses:

  • Fresh caught or market bought fish should be refrigerated at or below 40°F.
  • Keep cooked fish at a temperature 140°F or higher.
  • Pick up salmon at the end of a grocery shopping trip.
  • Throw away fishy or pungent smelling fish.
  • Defrost frozen fish in the refrigerator.
Fish oil supplements in a clear glass bowl

What about fish oil supplements?

Food first is a good motto, but sometimes that doesn’t work out. Dietary supplements are certainly an option for those that don’t like fish or may want a higher dose of EPA and/or DHA. For example, those with heart disease are recommended to take 1 gram or more per day which may be difficult with food alone.

Fish oil supplements are safe for most people. Commonly reported side effects are mild and include fishy taste and burp-back, bad breath, nausea, gastrointestinal discomfort, diarrhea, headache, and heartburn.

There is not an Upper Limit (UL) set for omega-3s, but high doses should be followed by a healthcare provider. The FDA recommends staying under 2 grams per day when consuming a dietary supplement. Those taking blood thinner medications (e.g., Warfarin) should be monitored by a physician if taking high doses due to the antiplatelet effects (blood-thinning) of omega-3s. However, the FDA stated omega-3s have not led to clinically significant bleeding episodes even in very high dose pharmaceutical-grade fish oil supplements [source].

Take-home message

Fish is an amazing food with incredible mind-body benefits! It’s an extraordinary food rich in high-quality protein, protective omega-3 fats, vitamins, and minerals.  Unfortunately, Americans aren’t eating enough. It has been estimated that ~80% of all adults aren’t getting the recommended two servings per week [source]. If that’s you, eat more. Get creative. Your body and mind will love you for it!

Fish recipes to try

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Jessica Gavin

I'm a culinary school graduate, cookbook author, and a mom who loves croissants! My passion is creating recipes and sharing the science behind cooking to help you gain confidence in the kitchen.

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  1. JJ says

    Whoa…one of the best articles I’ve read in a long time. Tip-to-tail coverage…I don’t think you left anything out. Thanks for posting.

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