What Happens to Your Body When You Eat Fish Regularly

From a casual canned tuna sandwich to fancy seared salmon, fish is a versatile, tasty way to reap some impressive health benefits.

The Dietary Guidelines for Americans suggest healthy adults consume 8 to 10 ounces of fish every week. Despite its robust nutrition, there are potential downsides, too, depending on what types of fish you’re choosing. Keep reading to learn what happens when you eat fish regularly, including the pros and cons and tips for choosing a nutrient-packed (and safe) catch of the day.

Fish Nutrition Facts

Here is the nutrition information for 100 grams (about 3.5 ounces) of three varieties of fish:

White Tuna, Canned in Water

• Calories: 128
• Total Carbohydrates: 0 g
• Dietary Fiber: 0 g
• Total Sugars: 0 g
• Protein: 24 g
• Total Fat: 3 g
• Saturated Fat: <1 g
• Sodium: 377 mg
• Vitamin D: 80 IU
• Omega-3: 880 mg
• Calcium: 14 mg
• Potassium: 237 mg

Cooked Atlantic Cod

• Calories: 89
• Total Carbohydrates: 0 g
• Dietary Fiber: 0 g
• Total Sugars: 0 g
• Protein: 19 g
• Total Fat: 1 g
• Saturated Fat: 0 g
• Sodium: 66 mg
• Vitamin D: 39 IU
• Omega-3: <1 mg
• Calcium: 12 mg
• Potassium: 207 mg

Cooked Salmon

• Calories: 153
• Total Carbohydrates: 0 g
• Dietary Fiber: 0 g
• Total Sugars: 0 g
• Protein: 25 g
• Total Fat: 5 g
• Saturated Fat: 1 g
• Sodium: 90 mg
• Vitamin D: 522 IU
• Omega 3: 674 mg
• Calcium: 8 mg
• Potassium: 439 mg

5 Health Benefits of Regularly Eating Fish 

1. You May Improve Your Heart Health

Fish, particularly oily cold-water fish (like salmon) provides omega-3 fatty acids. It’s one main reason why eating fish is associated with a lower risk for cardiovascular disease and stroke. In fact, research shows that for every 20 grams per day of fish you eat (that’s less than an ounce!), your risk of cardiovascular disease and mortality decrease by 4%.

2. You May Support Your Baby’s Brain Health If You Are Pregnant

Fish intake during pregnancy is encouraged because it supplies nutrients that support a baby’s developing brain. Eating omega-3-rich foods like fish may also help reduce the risk of preterm birth, research shows. If you are pregnant, focus on lower-mercury fish, such as salmon and cod. 

3. You May Reap Cognitive Benefits

Fish provides a handful of brain-health-supporting nutrients, including vitamin B12, choline and omega-3 fatty acids. Data suggests that fish intake is associated with a reduction in the development of mild cognitive decline and Alzheimer's disease. One study on elderly people found that those who were following the MIND diet (an eating pattern that may help reduce the risk of dementias) who were instructed to eat fish weekly had improved cognitive function after 12 weeks compared to a group that didn’t eat fish. One tip: Avoid fried fish, which has been shown to be a drag on brainpower.

4. You May Experience Better Mental Health 

There may be a link between eating fish and a better mood. Low levels of omega-3 fatty acid and vitamin D, both nutrients found in high quantities in some fish, have been linked to depressive disorders. Research suggests that omega-3s may play a role in mental health, including potentially decreasing the risk of depression. Diet is just one factor in mental health, though there are some foods, like cold-water seafood, that can help support your mood. Talk to your provider if you’re concerned about your mental health. 

5. You May Reduce Some Inflammation

Chronic inflammation is linked to numerous health conditions, including cancer, heart disease, arthritis and diabetes. Among the nutrients that may help manage chronic low-grade inflammation, omega-3 fatty acids are one of the best. Oily fish supplies DHA and EPA, two omega-3 fatty acids that have been found to help quell inflammation. In fact, diets that contain oily fish have also been found to reduce markers of inflammation in people who are at a higher risk for heart disease.

Potential Downsides

With all of the positives that eating fish can offer, there are some noteworthy potential downsides. Here are some “watch-outs” if you are a fish eater.

• Allergic reactions: A fish allergy can cause a severe and potentially life-threatening condition known as anaphylaxis. Symptoms of a fish allergy can range from mild, such as hives, itching or nasal congestion, to severe, including difficulty breathing, dizziness or loss of consciousness.
• Mercury exposure: Some types of fish, like shark and swordfish, are high in contaminants such as mercury, which is a particular risk for pregnant people and children. There are many low-mercury fish to choose from, such as cod, anchovy, tilapia, freshwater trout and salmon.
• Foodborne illness: If fish isn't properly handled or cooked, it can harbor bacteria and viruses, potentially leading to food poisoning. Purchase fish and shellfish from reputable suppliers, store them at the correct temperatures and cook them thoroughly to minimize risk. 

Best Ways to Cook and Enjoy Fish

Cooking your fish in an enjoyable—and health-promoting—way is key. Here are some best ways to cook fish:

• Grilling: Grilled fish, when prepared correctly, should be moist, flavorful and have a slightly crispy exterior, making it a delightful and healthy meal option. Prepare your fish with a marinade, like our Grilled Fish with Garlic Marinade, brush on a zesty butter prior to cooking like our Lemon-Garlic Grilled Tilapia or rub with spice like this Grilled Red Snapper.
• Steaming: Allowing warm, moist air to cook the fish preserves its delicate flavor. Steamed fish pairs well with lightly sautéed vegetables or a fresh salad for a well-rounded, healthy meal. Try our Ginger White Fish & Cabbage.
• Poaching: A gentle cooking method, poaching results in nice, tender fillets. Serving poached fish with a simple sauce made from the poaching liquid and a side of whole grains, such as quinoa or farro, can make a nutritious and satisfying meal. A classic way to enjoy poached fish is by eating Poached Salmon with Fennel & Lemon. 
• Baking: A versatile and easy cooking method, baked fish pairs well with roasted vegetables or a hearty grain salad. Our Baked Fish Fillets recipe goes with just about anything.

The Bottom Line

Eating fish every week is a healthy habit, and leading organizations like the American Heart Association recommend eating fish regularly. Aim for 8 to 10 ounces of fish in your diet every week (about two servings) to support your heart and brain health, mood and more. Choose lower-mercury fish when shopping, such as salmon, light tuna, tilapia or cod. Make sure to stick to cooking methods like grilling, baking and steaming, and avoid frying fish.