Omega-3 in fish: How eating fish helps your heart
The omega-3 fatty acids in fish are good for the heart. Find out why the heart-healthy benefits of eating fish usually outweigh any risks.
If you're worried about your heart health, eating at least two servings of fish a week could reduce your risk of heart disease.
The American Heart Association recommends eating fish rich in unsaturated fats at least twice a week. All fish are a good source of protein, vitamins and minerals. But fatty fish contain omega-3 fatty acids. Omega-3s and other nutrients in fish may improve heart health. They also may lower the risk of dying of heart disease.
Some people may worry about mercury or other contaminants in fish. But the benefits of eating fish as part of a healthy diet usually outweigh the possible risks of exposure to contaminants. Learn how to balance these concerns with adding a healthy amount of fish to your diet.
What are omega-3 fatty acids, and why are they good for my heart?
Omega-3 fatty acids are a type of unsaturated fatty acid. They may lower inflammation in the body. Inflammation in the body can hurt blood vessels. Blood vessel damage may lead to heart disease and stroke.
Omega-3 fatty acids may:
- Keep the heart healthy by slightly lowering blood pressure.
- Lower levels of fats called triglycerides in the blood.
- Lower the risk of irregular heartbeats.
Try to eat at least two servings a week of fish, especially fish that's rich in omega-3 fatty acids. Doing so appears to reduce the risk of heart disease, particularly sudden cardiac death.
Does it matter what kind of fish I eat?
Many types of seafood contain small amounts of omega-3 fatty acids. Fatty fish contain the most omega-3 fatty acids and seem to benefit the heart the most.
Good omega-3-rich fish options include:
- Salmon.
- Sardine.
- Atlantic mackerel.
- Cod.
- Herring.
- Lake trout.
- Canned, light tuna.
How much fish should I eat?
The U.S. Food and Drug Administration (FDA) recommends fish as part of a healthy diet for most people. But people in some groups should limit how much fish they eat.
Most adults should eat two servings of omega-3-rich fish a week. A serving size is 4 ounces (113 grams) or about the size of a deck of cards.
If you are pregnant, are planning to get pregnant or are breastfeeding, do not eat fish that's typically high in mercury. This includes shark, swordfish, king mackerel and tilefish. Limit the amount of other fish you eat to:
- No more than 12 ounces (340 grams) of fish and seafood in total a week.
- No more than 4 ounces (113 grams) of albacore tuna a week.
You can still get heart-healthy benefits from a variety of seafood and fish that are typically low in mercury, such as salmon and shrimp.
Young children also should not eat fish that contain potentially high levels of mercury. Kids should eat fish from choices lower in mercury once or twice a week. The serving size of fish for kids younger than age 2 is 1 ounce (28 grams) and increases with age.
To get the most health benefits from eating fish, pay attention to how it's cooked. For example, grilling, broiling or baking fish is a healthier option than is deep-frying.
Does mercury contamination outweigh the health benefits of eating fish?
If you eat a lot of fish containing mercury, the toxin can build up in your body. It's unlikely that mercury would cause any health concerns for most adults. But mercury is very harmful to the development of the brain and nervous system of unborn babies and young children.
For most adults, the benefits of omega-3 fatty acids outweigh the risk of getting too much mercury or other toxins. The main toxins in fish are mercury, dioxin and polychlorinated biphenyls, also called PCBs. The amounts of toxins depend on the type of fish and where it's caught.
A little bit of mercury occurs naturally in the environment. But pollution from factories and other industries can produce mercury that collects in lakes, rivers and oceans. That pollution can end up in the food that fish eat.
When fish eat this food, mercury builds up in their bodies. Large fish that are higher in the food chain eat smaller fish. So large fish get even more mercury. The longer a fish lives and eats, the larger it grows and the more mercury it can collect. Fish that may contain higher levels of mercury include:
- Shark.
- Tilefish.
- Swordfish.
- King mackerel.
Are there any other concerns related to eating fish?
Some studies say high levels of omega-3 fatty acids in the blood increase the risk of prostate cancer. But other studies say high levels of omega-3s might prevent prostate cancer.
None of these studies was definite. More research is needed. Talk with a health care professional about what this potential risk might mean to you.
Some researchers also are concerned about eating fish grown on farms as opposed to fish caught in the wild. Antibiotics, pesticides and other chemicals may be used in raising farmed fish. But the FDA says the levels of contaminants in farmed fish don't seem to be bad for health.
Can I get the same heart benefits by taking an omega-3 supplement or eating other foods that contain omega-3 fatty acids?
Eating fish rich in omega-3 fatty acids and other nutrients seems to be better for the heart than just using supplements. If you don't want or like fish, other foods that have some omega-3 fatty acids are:
- Flaxseed and flaxseed oil.
- Walnuts.
- Canola oil.
- Soybeans and soybean oil.
- Chia seeds.
- Green leafy vegetables.
- Cereals, pasta, dairy and other food products with added omega-3 fatty acids.
But the heart-healthy benefits from eating these foods do not seem to be as strong as those from eating fish.
From Mayo Clinic to your inbox
Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.
To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and website usage information with other information we have about you. If you are a Mayo Clinic patient, this could include protected health information. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.
Aug. 25, 2023
- Fish and omega-3 fatty acids. American Heart Association. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/fish-and-omega-3-fatty-acids. Accessed March 25, 2022.
- Mozaffarian D. Fish oil: Physiologic effects and administration. https://www.uptodate.com/contents/search. Accessed March 25, 2022.
- Khan SU, et al. Effect of omega-3 fatty acids on cardiovascular outcomes: A systematic review and meta-analysis. Eclinical Medicine. 2021; doi:10.1016/j.eclinm.2021.100997.
- Goel A, et al. Fish, fish oils and cardioprotection: Promise or fish tale? International Journal of Molecular Sciences. 2018; doi:10.3390/ijms19123703.
- Advice about eating fish. U.S. Food and Drug Administration. https://www.fda.gov/food/consumers/advice-about-eating-fish. Accessed March 25, 2022.
- Bowen KJ, et al. Omega-3 fatty acids and cardiovascular disease: Are there benefits? Current Treatment Options in Cardiovascular Medicine. 2016; doi:10.1007/s11936-016-0487-1.
- Abdelhamid AS, et al. Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews. 2020; doi:10.1002/14651858.CD003177.pub5.
- Willet W, et al. Food in the Anthropocene: The EAT-Lancet Commission on healthy diets from sustainable food systems. Lancet. 2019; doi:10.1016/S0140-6736(18)31788-4.
- Del Gobbo LC, et al. Omega-3 polyunsaturated fatty acid biomarkers and coronary heart disease. JAMA Internal Medicine. 2016; doi:10.1001/jamainternmed.2016.2925.
- Siscovick DS, et al. Omega-3 polyunsaturated fatty acid (fish oil) supplementation and the prevention of clinical cardiovascular disease. Circulation. 2017; doi:10.1161/CIR.0000000000000482.
- Oken E. Fish consumption and marine omega-3 fatty acid supplementation in pregnancy. https://www.uptodate.com/contents/search. Accessed March 25, 2022.
- Questions & answers from the FDA/EPA advice about eating fish for those who might become or are pregnant or breastfeeding and children ages 1 to 11 years. U.S. Food and Drug Administration. https://www.fda.gov/food/consumers/questions-answers-fdaepa-advice-about-eating-fish-those-who-might-become-or-are-pregnant-or. Accessed March 25, 2022.
- Saavedra S, et al. Impact of dietary mercury intake during pregnancy on the health of neonates and children: A systematic review. Nutrition Reviews. 2022; doi:10.1093/nutrit/nuab029.
- Wang Y, et al. Dietary fish and omega-3 polyunsaturated fatty acids intake and cancer survival: A systematic review and meta-analysis. Critical Reviews in Food Science and Nutrition. 2022; doi:10.1080/10408398.2022.2029826.
See more In-depth
Products and Services
See also
- Health foods
- Angina
- Atkins Diet
- Automated external defibrillators: Do you need an AED?
- Blood Basics
- Blood tests for heart disease
- Bradycardia
- Transplant advances
- Butter vs. margarine
- Calcium supplements: A risk factor for heart attack?
- Can vitamins help prevent a heart attack?
- Cardiac ablation
- Cardiac amyloidosis — Treatment options
- Cardiac amyloidosis — What is amyloid and how does it affect the heart
- Cardiac catheterization
- Cardioversion
- Chelation therapy for heart disease: Does it work?
- Chest X-rays
- Complete blood count (CBC)
- Coronary angiogram
- Coronary angioplasty and stents
- Coronary artery bypass surgery
- Coronary artery spasm: Cause for concern?
- Cough
- CT scan
- Daily aspirin therapy
- Dizziness
- Don't get tricked by these 3 heart-health myths
- Echocardiogram
- Ejection fraction: What does it measure?
- Electrocardiogram (ECG or EKG)
- Heart transplant to treat dilated cardiomyopathy: Elmo's story
- Erectile dysfunction: A sign of heart disease?
- Exercise and chronic disease
- Fasting diet: Can it improve my heart health?
- Fatigue
- Flu Shot Prevents Heart Attack
- Flu shots and heart disease
- Grass-fed beef
- Healthy Heart for Life!
- Heart and Blood Health
- Heart arrhythmia
- Heart attack
- Heart attack prevention: Should I avoid secondhand smoke?
- Heart attack symptoms
- Heart Attack Timing
- Heart disease
- Heart disease in women: Understand symptoms and risk factors
- Heart-healthy diet: 8 steps to prevent heart disease
- Heart murmurs
- Heart Rhythm Conditions
- Heart transplant
- Herbal supplements and heart drugs
- Holter monitor
- Honey: An effective cough remedy?
- Implantable cardioverter-defibrillators (ICDs)
- Leg swelling
- Mediterranean diet
- Menus for heart-healthy eating
- NSAIDs: Do they increase my risk of heart attack and stroke?
- Nuclear stress test
- Numbness
- Nuts and your heart: Eating nuts for heart health
- Omega-6 fatty acids
- Organ transplant in highly sensitized patients
- Pacemaker
- Pericardial effusion
- Polypill: Does it treat heart disease?
- Pseudoaneurysm: What causes it?
- Pulmonary edema
- Red wine, antioxidants and resveratrol
- Shortness of breath
- Silent heart attack
- Sitting risks: How harmful is too much sitting?
- Statins
- Heart disease prevention
- Stress symptoms
- Stress test
- Tachycardia
- The Last Brother's Heart
- Integrative approaches to treating pain
- Nutrition and pain
- Pain rehabilitation
- Self-care approaches to treating pain
- Trans fat
- Triathlete transplant
- Coronary angioplasty
- Video: Heart and circulatory system
.