Though the terms fish oil and omega-3 are often used interchangeably in the supplement world, they aren’t exactly the same. Omega-3 fatty acids are a type of fat that is a component of fish oil but also comes from some plant-based sources. Read on to learn more about omega-3 fatty acids, fish oil, and the potential health benefits of each.
What is omega-3?
Omega-3 fatty acids are a type of polyunsaturated fat that have essential roles in the human body. According to the National Institutes of Health (NIH), omega-3 fatty acids help form cell membranes, provide energy for the body, and are used for eicosanoid synthesis. Eicosanoids are signaling molecules that have many functions in the immune, cardiovascular, pulmonary, and endocrine systems.
Three omega-3 fatty acids — alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) — are most commonly studied for their effects on humans.
ALA is an essential fatty acid, which means it’s required for the human body to function properly. However, the body cannot produce ALA, so it must be consumed in the diet. ALA is found in many plants but is the most abundant in flaxseed, soybean, canola, chia seeds, and walnuts.
DHA and EPA can be converted from ALA in the body, but the conversion rate is limited, so it is best to consume them from the diet. Common omega-3 sources of DHA and EPA are fish, especially fatty cold-water varieties, krill, and seaweed.
Supplements and some fortified foods also contain omega-3 fatty acids. Foods commonly fortified with omega-3s include milk, yogurt, eggs, juices, and soy drinks.
Benefits of taking omega-3
According to the 2003-2014 National Health and Nutrition Examination Survey data, Americans' average intake of EPA and DHA was low, at ~100 mg daily. Though dietary intake was low, only 7.4% of people consistently took omega-3 supplements.
Omega-3 supplements may provide many health benefits, including lowering mortality risk. In an analysis of blood DHA levels and risk of mortality, researchers compared the mortality risk between the group of people with the lowest circulating levels of DHA in their blood and those with the highest circulating levels of DHA.
Researchers found a 17% lower risk of mortality by any cause in the group of people with the highest circulating levels of DHA in their blood. The results included a 21% lower risk of death from cardiovascular disease, a 17% lower risk of death from cancer, and a 15% lower risk for all other causes of death. This analysis found that about half of the people in the group with the highest DHA blood levels took omega-3 supplements.
Pregnant and breastfeeding individuals may also benefit from omega-3 supplements if their intake is inadequate, though study results are mixed. Infant formulas are often fortified with DHA due to possible neurodevelopmental benefits for babies. In these cases, it is paramount to consult with your healthcare provider prior to consuming or giving children omega-3 supplements.
Potential side effects of omega-3
Most of the side effects from omega-3 supplements are due to fish oil. Fish oil can cause side effects like fishy aftertaste, fishy burps, or nausea. Omega-3 supplements that are plant-based should not have a fishy aftertaste, though an individual could have gastrointestinal symptoms from any dietary supplement.
People who take anticoagulation medications should use omega-3 supplements with caution. Omega-3 supplements can increase the risk of bleeding. Although this is rare, check with a healthcare provider before starting an omega-3 supplement if you take other medications.
What is fish oil?
As the name suggests, fish oil is a type of oil derived from fish. It is typically extracted from the tissues of fatty fish. Extracting fish oil requires many steps, including cooking, pressing, and separating the fat from the other liquid components.
Salmon, sardines, mackerel, tuna, and herring are often used for fish oil. According to the NIH, farmed fish typically have higher levels of EPA and DHA than fish caught in the wild. The diet of the fish affects its omega-3 content.
Benefits of taking fish oil
Fish oil benefits are similar to the benefits of omega-3 fatty acids noted above. Fish oil supplements contain EPA and DHA, which are associated with health benefits such as decreased mortality risk and complications for those with certain heart issues.
Though some studies have found conflicting benefits of omega-3 supplementation on heart health, the American Heart Association (AHA) science advisory recommends using fish oil supplements for people with coronary heart disease (CHD). Since omega-3 supplementation is relatively safe, the panel believes the treatment is justified even if the results are modest. The AHA also recommends omega-3 supplementation for some patients with heart failure to reduce the risk of death and hospitalizations.
Apart from EPA and DHA, fish liver oil supplements contain other vitamins, like vitamins A and D, which are essential for many bodily functions.
Potential side effects of fish oil
Generally, side effects reported by people who take fish oil supplements include fishy aftertaste, fishy burps, bad breath, heartburn, and nausea.
Fish oil supplements also may cause allergic reactions for those with fish or shellfish allergies. Read labels carefully to ensure you choose a vegetarian or plant-based omega-3 supplement free from any fish.
People taking anticoagulation medications, which help prevent blood clots, and fish oil supplements may have a greater risk of bleeding. If you take anticoagulation medications, check with a healthcare provider before starting fish oil supplements.
Fish oil vs. omega-3: key differences
Omega-3 fatty acids are a component of fish oil. While fish oil contains omega-3 fatty acids, not all omega-3 fatty acids come from fish oil.
Fish oil supplements contain more than just omega-3s. They also have other fat components and may contain additional vitamins. Many fish liver oil supplements, such as cod liver oil, also contain vitamins A and D.
The form of fatty acids used in omega-3 supplements affects bioavailability. However, according to the NIH, all forms increase plasma EPA and DHA levels. Studies have mixed results on whether krill oil has a higher bioavailability of omega-3s than fish oils.
There are sustainability and environmental concerns about using wild-caught fish as an omega-3 source. Climate change and overfishing may affect the future supply of wild-caught fish high in omega-3 fatty acids, and some wild fisheries already operate at unsustainable levels.
Consider whether the fish used in your supplement are wild-caught or farm-raised. If the fish are wild-caught, some brands will indicate if they were fished with sustainable practices.
How to choose between fish oil and omega-3 supplements
When choosing a fish oil or omega-3 supplement, consider the following factors:
- Preferred form. Omega-3 and fish oil supplements most commonly come in capsule or soft gel pill form. Some brands also offer gummies and chews or liquid supplements.
- Dose. Consider your desired dose of omega-3 fatty acids. Some brands require two capsules or soft gels per serving, while others contain the full dose in one pill.
- Flavor. Some omega-3 supplements have added fruit flavors to make them taste more appealing and reduce fishy taste and odor.
- Quality. To ensure that you choose a product that contains what the label states, look for supplements verified by organizations such as United States Pharmacopeia (USP).
- Dietary restrictions and allergies. If you have a fish or shellfish allergy, read the ingredients on the supplement label carefully to ensure the supplement is safe. Choose a plant oil-based omega-3 supplement until you can review options with a healthcare provider. Additionally, anyone following a vegan diet will likely prefer a plant-based omega-3 supplement that is certified vegan.
Consider whether you eat enough fish or plant-based food sources to meet guidelines without adding an omega-3 supplement. If your fish intake is less than two times per week or you have a health condition requiring a higher dose, you may need a supplement to meet the recommended levels.
The Institute of Medicine (IOM) established adequate intake (AI) levels for alpha-linolenic acid, the only essential omega-3 fatty acid for humans. The AI level for adult men and AMAB (assigned male at birth) individuals after the age of 19 is 1.6 grams per day. In general, the AI for women and AFAB (assigned female at birth) individuals is 1.1 grams per day. However, for pregnant individuals, the AI increases to 1.4 grams/day, and for lactating individuals, it is 1.3 grams/day. The IOM does not give recommended levels for the other common omega-3 fatty acids, though many health benefits are associated with EPA and DHA.
Recommended dosages of supplements vary in clinical trials. In studies reviewed for a Science Advisory from the American Heart Association, all of the studies except one used an average dose of ~1,000 mg of omega-3 supplements.
📝 Healthnews editor's top picks
If you're considering fish oil supplementation, our article on the best fish oil supplements on the market may be helpful. But while you're here, check out our top 3 picks:
1. Best fish oil supplement overall — HUM
- Sustainably sourced fish oil and vitamin E
- Third-party tested
- Clear sustainability practices
2. Best fish oil supplement with enhanced absorption — Utzy
- Premium-grade fish oil sourced sustainably
- Triglyceride formulation for enhanced digestion
- Third-party tested
3. Best fish oil supplement for those on a budget — BulkSupplements.com
- Manufactured under GMP
- Budget-friendly
- Positive customer reviews
Bottom line
Fish oil and omega-3 supplements are generally considered safe for most people. While more research is needed in some areas, omega-3 supplements have some proven health benefits, such as reducing mortality risk. Check with your healthcare provider if you currently take other medications to ensure omega-3 supplements are right for you or to ask what dose you should take for your specific health concerns.
FAQ
Can I take both fish oil and omega-3 supplements together?
Fish oil already contains omega-3 fatty acids, so you likely don’t need fish oil and an additional omega-3 supplement. Read the label on the supplement to determine how much omega-3s it contains. Consider whether you’d like a fish oil-based or plant-based omega-3 supplement.
Is it better to take omega-3 or fish oil?
Both omega-3 and fish oil supplements have similar health benefits. Fish oil contains omega-3 fatty acids. Consider your preference, whether you’d prefer a plant-based or vegan supplement or if you’re comfortable with fish oil. You can also try eating two servings of fatty fish per week to increase your omega-3 intake.
Is plant omega-3 as good as fish oil?
Though supplement bioavailability varies, omega-3 and fish oil supplements have similar health benefits. Many plant oils contain ALA, an essential fatty acid for humans. Plant-based algae oils also contain DHA and EPA. Whether you choose a plant- or fish-oil-based supplement, look for supplements that contain DHA and EPA.
Is fish oil 100% omega-3?
No, fish oil isn’t 100% omega-3. It also contains other components and types of fats, as well as vitamins like A and D. However, fish oil is a common source of omega-3 fatty acids in both the diet and supplement form.
-
While fish oil contains omega-3 fatty acids, not all omega-3 fatty acids come from fish oil.
-
Consider allergies, dietary restrictions, environmental concerns, and supplement form when choosing an omega-3 supplement option.
-
Omega-3 supplements have many potential health benefits, such as decreasing mortality risk and complications from certain heart conditions.
10 resources
- National Institutes of Health. Omega-3 fatty acids.
- National Institutes of Health. Dietary supplement label database.
- National Center for Complementary and Integrative Health. Omega-3 supplements: in depth.
- Circulation. Omega-3 polyunsaturated fatty acid (fish oil) supplementation and the prevention of clinical cardiovascular disease: a science advisory from the American Heart Association.
- Mayo Clinic Proceedings. Circulating docosahexaenoic acid and risk of all-cause and cause-specific mortality.
- Nutrients. Omega-3 long-chain polyunsaturated fatty acids intake by ethnicity, income, and education level in the United States: NHANES 2003-2014.
- Science Direct. Fish and seafood: nutritional value.
- Science Direct. Sustainable optimization of global aquatic omega-3 supply chain could substantially narrow the nutrient gap.
- Marine Drugs. Omega-3 rich oils from marine side streams and their potential application in food.
- United States Pharmacopeia. USP's dietary supplements verification program.
Your email will not be published. All fields are required.