What Are Omega-3s?
Omega-3 fatty acids are “good fats” your body needs to function. These fatty acids come in three forms. Alpha-linolenic acid (ALA) is found mainly in plant oils, while seafood is the best source of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Your body absorbs EPA and DHA more easily than the plant-based ALA.
ALA is an essential fatty acid, meaning you need to get it from your diet. Your body can convert ALA into small amounts of DHA and EPA. But getting more from food or supplements helps support many of your body's processes.
Omega-3 supplements include fish oil, cod liver oil, and vegetarian algal oil, but the forms of this supplement vary widely. Doctors sometimes prescribe high doses to help lower heart disease risk factors like high triglyceride levels, or certain fats in your blood. But these doses could have side effects in healthy people, so talk to your doctor before adding a supplement to your diet.
Researchers have studied the effect of omega-3 fatty acids in relation to many other conditions, including asthma, cancer, depression, psoriasis, and inflammatory bowel diseases such as Crohn's disease and ulcerative colitis. While some of these studies have been promising, they're still inconclusive.
Types of omega-3s
Studies have generally looked at fish oils as the source for omega-3 fatty acids. While plant sources with ALA may have the same benefits, we know less about them. For now, fish oils with DHA and EPA have the more established benefit.
Omega-3s play important roles throughout your body. Getting enough in your diet is linked to a lower risk of chronic diseases like heart disease and arthritis, as well as cognitive conditions like Alzheimer’s disease.
Research shows these fatty acids support your health in several ways, including:
A diet high in omega-3s is linked to a lower risk of heart disease. Studies show omega-3s reduce cholesterol and triglyceride levels. This effect can keep your arteries clear from plaque buildup and your blood vessels smooth and flexible, putting less strain on your heart.
Omega-3s may reduce inflammation in your body. While inflammation is a normal response to infection and stress, high levels over time can lead to chronic diseases like coronary artery disease, arthritis, and possibly depression.
Research is ongoing to see whether omega-3s could be used to treat different conditions. But studies suggest that the effects of omega-3s could reduce your risk of many inflammatory and autoimmune diseases.
Some studies show that people who take omega-3s may have a lower risk of developing Alzheimer’s disease, dementia, and other conditions of cognitive decline. Scientists don’t fully understand why omega-3s may have this effect, and much more research is needed.
How Much Omega-3 Is Right for You?
The recommendations for how much omega-3 you should get each day is based on your body’s ALA requirement, since it's the only type that's essential. But a healthy diet includes sources of DHA and EPA as well.
On average, men should get 1.6 grams of omega-3s per day and women 1.1 grams. If you're pregnant, aim to get 1.4 grams per day.
The American Heart Association recommends eating 2-4 servings of fish per week, especially if you have a history of heart disease. Try to eat a variety of fish to avoid any negative effects from environmental pollutants.
Omega-3s are the cousins of omega-6s — other types of fatty acids that have similar health benefits. But you get the best benefits from getting adequate levels of both.
Research shows that most people get about 10 times more omega-6 fats than omega-3s. Try adding a mix of these eight foods to your diet to ensure a healthy balance of essential fats:
1. Flaxseed oil
One tablespoon of flaxseed oil has 7.26 grams of the ALA omega-3, more than seven times your daily recommendation. You can get 2.35 grams of omega-3 from a tablespoon of whole flaxseeds as well.
Flaxseed oil has a low smoke point, a measure of how high oil can be heated before it starts to burn. So cooking with it can reduce the nutritional value and may release harmful compounds.
It’s best used in dressings, dips, or smoothies. The seeds are great to add to cereals or baked goods. Or you can mix them with water to make a vegetarian egg substitute.
2. Canola oil
Because flaxseed oil isn’t suitable for cooking, canola oil’s high smoke point makes it a great way to add omega-3s to sautéed, fried, or baked dishes. You can use canola oil in place of most other cooking oils and get 1.28 grams of ALA in every tablespoon.
3. Chia seeds
With 2.53 grams of omega-3s per tablespoon, chia seeds are a good alternative for people who don’t like flaxseeds’ nutty taste. They also have high fiber and protein levels, making them a good source of nutrients for people on a plant-based diet.
Almost all seafood has omega-3s, but cooked salmon is an especially good DHA and EPA source with 1.24 and 0.59 grams, respectively. While fresh fish doesn’t usually have ALA, canned salmon can have up to 0.04 grams in addition to its DHA and EPA content. Other large fish like mackerel, trout, tuna, and sea bass also have high omega-3 levels.
5. Foraging fish
After large fish like salmon, foraging fish have some of the highest levels of EPA and DHA omega-3s. This group includes herring, with 1.71 grams per 3-ounce serving, and canned sardines, with 1.19 grams.
Shellfish is a uniquely good source of omega-3s because many types have all three forms of omega-3s: ALA, DHA, and EPA. This includes oysters, with a total content of 0.67 grams per 3-ounce serving; lobster, with 0.21 grams; and scallops, with 0.15 grams for the same portion.
Walnuts are rich in many nutrients, including omega-3s. About seven walnuts have up to 1.28 grams of ALA. And if you include them in a chicken dish, you get an added boost. While a 3-ounce portion of chicken breast has only 0.03 grams of omega-3s, it’s made up of DHA and EPA, balancing your meal.
Soybeans and soybean products like tofu are a rich source of omega-3s, especially if you're a vegan or vegetarian. A 100-gram serving (about 2/3 cup) of edamame, which are boiled, salted soybeans served inside their pods, has 2.16 grams of omega-3s.
Omega-3 Side Effects
There are some risks to adding an omega-3 supplement to your diet, including:
- Side effects. Omega-3 fatty acid supplements might cause an upset stomach or diarrhea. These side effects are worse at higher doses.
- Interactions. If you take blood thinners, antiplatelet drugs, or anti-inflammatory painkillers (like ibuprofen), talk to your doctor about using omega-3 fatty acids. The combination may increase the risk of bleeding. The same risks may apply to people taking supplements like ginkgo biloba.
- Risks. People who are pregnant or who have a high risk of diabetes, a high risk of bleeding (particularly those on "blood thinners"), or high LDL cholesterol should check with their doctor before taking omega-3 fatty acid supplements. At very high doses, they could increase the risk of hemorrhagic stroke.
- Mercury poisoning. Eating fish is generally the best way to get omega-3 fatty acids. But some fish contain higher levels of mercury, like king mackerel, swordfish, and albacore tuna. The benefits of eating fish are usually thought to outweigh the risks, but it's a good idea to limit how much you eat these high-mercury fish.