What’s the difference between ALA, EPA and DHA omega-3s?
There are three main omega-3s – EPA, DHA and ALA.
ALA (alpha-linolenic acid) comes from plants. ALA is a true “essential” omega-3 because we need to get this fat from the diet – our bodies can’t make it on their own. It’s found in seeds (flax, chia), nuts (walnuts) and oils (soybean, canola), to name a few. ALA can be converted to EPA and DHA in the body, but the rate at which that happens is very low.
EPA and DHA (eicosapentaenoic acid and docosahexaenoic acid, respectively), are omega-3s that come from marine (sea) sources. EPA and DHA are the omega-3s that have been shown to be the most protective of the heart. Scientific evidence also supports the role of EPA and DHA for brain, eye and prenatal health.
What is the difference between omega-3 and omega-6?
Both omega-6s (from plant oils such as corn, soybean and sunflower oils) and omega-3s (both EPA+DHA from marine sources such as fish and algae but also ALA from nuts and seeds) have a role in supporting healthy cells. However, EPA and DHA omega-3s are known for their powerful role in heart, brain and eye health and for supporting a healthy pregnancy and infant development. Unlike omega-6s and ALA omega-3s, EPA and DHA omega-3s come from marine sources such as fish and microalgae.
Most people are getting more than enough omega-6s in the diet. They are also getting enough ALA omega-3s but fall far short of the amount of EPA+DHA they need. That’s why making fish a regular part of your diet and taking omega-3 supplements are so important.
Are certain types of omega-3s better absorbed or digested than others?
There are several factors that play a role in digestion and absorption. Everybody is different and so is the ability to digest and absorb nutrients, including omega-3s.
There are small differences in absorption rates among the various forms of omega-3s. When adding an omega-3 supplement to your daily regimen, ensure that the supplement delivers adequate amounts of EPA and DHA (as shown on the Supplement Facts label).
If you are experiencing “fishy burps” from your omega-3 supplement, you may want to try a different brand – always look for a reputable brand of high-quality omega-3.
If you have questions consult your health care professional.
Is there a recommended intake for EPA and DHA omega-3s?
Although omega-3s are considered vital, there is no established Adequate Intake (AI) or Dietary Reference Intake (DRI) in the United States for EPA and DHA omega-3s. Governments in other countries and a variety of expert scientific bodies around the world have set recommendations between 250 and 1000 mg of EPA and DHA per day. Emerging research suggests that 1000 mg (1 g) of EPA+DHA is a good daily amount to target.
Are you getting enough omega-3s? Take our quiz to find out.
How do I choose the right omega-3 supplement?
The key to selecting a supplement that is right for you is to read the label to identify how much EPA and DHA is included in each serving. Amounts of total omega-3s, as well as EPA and DHA, all vary considerably between products, but should be clearly identified on the label. If they are not clearly identified, continue to look for a product that labels all of these important components.
- The Serving Size is listed here on the label. This is how much you need to ingest to obtain the amount of omega-3s, EPA and DHA listed on the label. Serving size may often be more than one capsule or softgel.
- The amounts of EPA and DHA are listed here. EPA and DHA are associated with different health benefits, so it is important that manufacturers clearly identify how much each serving contains. The amount of EPA and DHA in a supplement is generally less than the total amount of omega-3s. For example, some packaging will feature “Fish Oil 1000mg” but this describes the amount of total fish oil in the product and not the specific levels of EPA and DHA. For some health concerns, practitioners recommend patients take an omega-3 supplement that provides a specific level of EPA, DHA or both.
- This field contains the total amount of omega-3s per serving.
- This list contains all of the ingredients contained in the product, including the ingredients used to blend the oil and make the capsule. Ingredients, such as rosemary and d-alpha tocopherol (Vitamin E), are antioxidants that have been added to better preserve the fish oil and keep the product fresh tasting.
Are there any vegetarian food sources of EPA and DHA omega-3s? What about seaweed?
The only vegetarian source of EPA+DHA is found in marine microalgae. The EPA and DHA are encapsulated (that is, put into supplement form) or used to boost omega-3 levels in foods such as milk, spreads and even infant formula. Seaweed such as spirulina, chlorella, dulse and nori are not good sources of EPA and DHA omega-3s.
If my omega-3 supplement smells fishy, should I throw it out?
When it comes to fish oils (or other marine-based oils such as krill and algae), a mild fishy smell is normal. An extreme off-smell, however, is not. It is important to note that even a very fishy-smelling product is not unsafe, just unpleasant. If the product smells bad and is beyond its expiration date, then it should be thrown away.
Can I get my omega-3 or fatty acid levels tested?
Yes, you can have your omega-3 or fatty acid levels tested to see if you may have lower than recommended levels of omega-3s. Your current blood levels will help your healthcare practitioner determine the best consumption amount for you.
You can easily test your omega-3 blood levels using an at-home kit. The most common omega-3 blood test is the Omega-3 Index. The Omega-3 Index has three different types of results you can receive, from basic to complete. It also has tests specifically for prenatal DHA and omega-3 intake for pregnant women, and to measure DHA in breastmilk for nursing moms.
Should I be concerned about contaminants like mercury in fish or fish oil supplements?
Because of their natural environment, some fish may contain higher levels of mercury, PCBs (polychlorinated biphenyls), dioxins and other environmental contaminants than what may be found in a fish oil supplement. The benefits of eating fish far outweigh the potential risks when following established guidelines for the amount and type of fish to eat. Even pregnant women and children should eat more fish due to its health benefits. In the case of fish oil supplements manufacturers purify oils to reduce levels of environmental contaminates in finished products.
Some fish, like wild salmon, have lower levels of contaminants than fish like swordfish and tilefish, so understanding what fish have low levels of contaminants is important. Learn more seafood recommendations from Monterey Bay Aquarium Seafood Watch.
As for omega-3 dietary supplements, manufacturers purify the oil to reduce the level of environmental contaminants in the end product. Before the supplements are placed on store shelves the fish oil is tested to ensure it meets the GOED industry standard for contaminant levels.