What is omega-3?
Omega-3 fatty acids are a group of essential fatty acids that are required but not synthesized by the human body. There are three major omega-3 fatty acids in the human diet: ALA, EPA, and DHA. ALA is abundant in certain plant oils while EPA and DHA are abundant in fish oil, but can also be synthesized from ALA by the human body (Table 1).
Omega-3 refers to the polyunsaturated fatty acids that contain a double bond at the third carbon atom from the methyl end. Polyunsaturated fatty acids have two or more double bonds between carbon atoms on the carbon chain.
Omega-6 fatty acids are the opposite of omega-3 fatty acids and contain a double bond at the sixth carbon atom from the methyl end. While omega-3 fatty acids are anti-cardiovascular disease, anti-inflammation, and are generally under-supplied to the human body, omega-6 fatty acids are pro-cardiovascular disease, pro-inflammation, and over-abundant in modern western diets. More detailed information about the effects of omega-3 versus omega-6 fatty acids is available here.
|| Common Name
|| Dietary Sources
|| α-Linolenic acid
|| C18 : 3
|| Oils: flaxseed, olive, canola
|| Eicosapentaenoic acid
|| C20 : 5
|| Fish oil, marine algae
|| Docosahexaenoic acid
|| C22 : 6
|| Fish oil, marine algae
|| Linoleic acid
|| C18 : 2
|| Oils: corn, soybean,
|| Arachidonic acid
|| C20 : 4
|| Peanut oil. Small amount in meat,
dairy products and eggs
How is omega-3 used in the human body?
Omega-3 fatty acids are the precursors of many signaling molecules, regulators of gene expression, and make up structural components of the cell membrane. The two long chain omega-3 fatty acids, EPA and DHA, are also required in high levels in the brain and retina to support optimal neuronal functions.
How much omega-3 do I need in my diet?
The Dietary Guidelines for Americans recommends an omega-3 intake of 1.1 gram of ALA for females and 1.6 gram for males. This is equivalent to about 1 to 2 tablespoons of canola oil, or about 3 to 4 oz of salmon.
How can vegans get EPA and DHA in their diets?
The human body can convert ALA to EPA and DHA so vegans do not need to worry about dietary EPA and DHA as long as they are getting sufficient ALA from plant oils and/or nuts.
Is it better to get omega-3 fatty acids from food or from supplements?
It is always better to get your nutrients from your diet than from supplements. However, if you cannot get sufficient omega-3 in your diet, you should consider taking a supplement. People who have suffered a heart attack are normally advised by health care providers to take omega-3 supplements.
How do I increase my omega-3 intake?
We recommend using the GB HealthWatch Diet and Nutrition Evaluator to get an assessment of your current omega-3 intake level.
The following guidelines can help ensure you are getting a healthy dose of omega-3:
1. Increase the amount of omega-3 rich foods in your diet (See Top Foods).
2. Try to use canola oil or olive oil in home cooking to increase ALA levels in homemade foods. Please be aware that the level of ALA in olive oil (0.76%) is about half of the level in canola oil, so using olive oil alone without any other omega-3 rich sources will not provide sufficient dietary omega-3.
3. Limit corn oil, peanut oil, and cottonseed oil in home cooking. These oils contain high levels of polyunsaturated fatty acids, but have too much omega-6 and little to no omega-3.
4. Cut down on peanut and sunflower seed based snacks. These are fat-rich, energy-dense foods that lack omega-3.
5. Take omega-3 supplements if you cannot get enough omega-3 in your diet.