Does Flax Oil Contain Omega-3?

Getting enough omega-3 fatty acids can be challenging, especially for people with dietary restrictions that prevent consumption of fish or fish oil supplements. Flax oil, also known as flaxseed oil, may seem appealing because it is a vegetarian source rich in omega-3 fat. However, benefits of omega-3 fatty acids are largely attributed to the fatty acids in fish, which are different from the fatty acids present in flax oil. Understanding the distinctions between the different fatty acids will make it easier to choose the omega-3 source that suits your needs.

Features

The omega-3 fatty acid in flax oil is "essential," meaning that it must be obtained from diet. Most essential fats in western diets are omega-6 fatty acids, found in modern cooking oils and animal fats. In a 2002 review in "Biomedicine and Pharmacotherapy" Dr. A.P. Simopoulos explained that modern western diets have an omega-6 to omega-3 ratio of 15:1, compared to a healthier ratio of about 1:1 throughout most of human history. By substituting flax oil for other common cooking oils, the omega-6 to omega-3 ratio can be decreased.

Types

According to the USDA National Nutrient Database, fish contain the omega-3 fatty acids eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA. Flax oil contains the omega-3 fatty acid alpha-linolenic acid, or ALA, but it does not contain any EPA or DHA. Humans can convert ALA into EPA and DHA, but not very efficiently. In a 2002 review published in "Current Opinion in Clinical Nutrition & Metabolic Care," Dr. J. Thomas Brenna reported that humans convert less than 5% of dietary ALA to DHA. In fact, in 2009 an expert committee from the International Society for the Study of Fatty Acids and Lipids issued a statement in the journal "Prostaglandins, Leukotrienes and Essential Fatty Acids" saying that, for people consuming a typical western diet, supplementation with ALA only raises blood levels of EPA, but not DHA.

ALA Function

Because of their different fatty acid composition, flax oil and fish oil may not function interchangeably. Fewer studies have focused directly on the ALA in flax oil compared to DHA and EPA. Reported benefits of flax oil may be due to the reduction in omega-6/omega-3 ratio, as well as conversion of ALA to EPA in the body.

ALA Benefits

In 2008, Dr. Aliza Stark and colleagues published in "Nutrition Reviews" a summary of evidence supporting benefits of ALA consumption. They found evidence for cardiovascular protection from dietary ALA, as well as anti-inflammatory effects and improved mental health. However, they said that it is still unclear how the benefits of ALA compare to other omega-3 fatty acids.

Considerations

In a paper published in 2007 in the "Journal of the American Oil Chemists' Society," Dr W.S. Choo found that ALA was destroyed by cooking flax oil at high heat. To avoid this, use flax oil in uncooked preparations. Vegetarians may also consider taking DHA supplements, which are available sourced from marine algae rather than fish.