EPA, DHA and GLA, or eicosapentaenoic acid, docosahexaenoic acid and gamma-linolenic acid, as they are known to chemists, are dietary fats with important contributions to health and nutrition. Among their many vital functions in the body, EPA, DHA and GLA help form the brain and nervous system, maintain the fluidity of blood, and create the structure of cell membranes. The role of these nutrients can be illustrated, in part, by the consequences of deficiency or imbalance.
EPA is a member of the family of omega-3 fatty acids. Certain important anti-inflammatory hormones, known as eicosenoids, are derived from EPA. Healthy brain and heart development require adequate amounts of EPA, and conditions such as depression and attention deficit disorder respond well to EPA supplementation. Its anti-inflammatory properties make EPA useful in the prevention of cardiovascular disease and in the maintenance of healthy joints and prevention of various forms of arthritis, according to the University of Maryland Medical Center. You can obtain dietary EPA from cold-water fish.
DHA is more readily absorbed and used in greater quantities in the body than is EPA. Proper brain function relies on adequate amounts of DHA, which comprises 40 percent of the fatty acids in the membranes of brain cells, according to a study published in the January 2011 issue of "Molecular Neurobiology." Some evidence points to a connection between DHA deficiency and hostile and violent behaviors. Doctors have successfully used DHA to treat chemical addictions to drugs and alcohol. DHA is found primarily in fish oils and is derived from algae. Strict vegetarians or people who simply wish to avoid fish oil often obtain DHA by eating some of the same types of algae that fish eat.
GLA is an omega-6 fatty acid that, like EPA and DHA, you must obtain from your diet. While the other omega-6 oils -- linoleic acid and arachidonic acid -- promote inflammation, GLA is anti-inflammatory when it is converted into a form known as DGLA. GLA often helps diabetic neuropathy, certain forms of inflammatory arthritis and allergies. Sources of GLA include plant oils such as borage, evening primrose and black current seed.
Ratio of Omega-3 to Omega-6
It is possible that humans evolved on a diet consisting of a 1-1 ratio of omega-3 to omega-6 fatty acids, according to a study conducted at The Center for Genetics, Nutrition and Health and published in the October 2002 "Biomedicine and Pharmacotherapy," The modern Western diet has skewed that ratio to favor omega-6 fatty acids. As a result, the researchers of the study say, excesses of omega-6 fats in the diet represent a major factor in the rising rates of chronic and inflammatory diseases such as cardiovascular disease, cancer and autoimmune conditions. The authors recommend shifting to a healthier ratio of dietary fats to reduce the incidence of these diseases of modern life.
- University of Maryland Medical Center: EPA
- "Molecular Neurobiology"; Evolutionary Aspects of Diet: The Omega-6/Omega-3 Ratio and the Brain; A.P. Simopoulos; January 2011
- University of Maryland Medical Center: GLA
- "Biomedicine and Pharmacotherapy"; The Importance of the Ratio of Omega-6/Omega-3 Essential Fatty Acids; A.P. Simopoulos; October 2002