Omega-6 fatty acids

background

Omega-6 fatty acids are a family of polyunsaturated fatty acids including linoleic acid, gamma-linolenic acid, and arachidonic acid. In North America, omega-6 fatty acids are found in adequate amounts in the diet, as they are found in salad dressings, margarines, and other plant and animal oil sources. The negative reputation of omega-6 fatty acids is likely based on inadequate intakes of omega-3 fatty acids and not excessive omega-6 fatty acid intakes.
Although not commonly used alone as dietary supplements, there is some evidence in support of omega-6 fatty acids, in combination with omega-3 fatty acids, for attention-deficit hyperactivity disorder (ADHD) and coordination disorders, as well as eye disorders. Also, levels of certain omega-6 fatty acids in the blood were found to be lower in multiple sclerosis patients vs. healthy controls with similar dietary intakes. However, there is a lack of evidence in support of supplementation in multiple sclerosis patients.

Related Terms

Adrenic acid, arachidonic acid, calendic acid, dihomo-gamma-linolenic acid, docosadienoic acid, docosapentaenoic acid, eicosadienoic acid, eicosanoids, gamma-linolenic acid, hexanal, hydroxynonenal, linoleic acid, n-6.
Note: This monograph discusses omega-6 fatty acids in general and is based on the literature search term omega-6 fatty acids. The effects of omega-6 fatty acids within the body as well as supplemental omega-6 fatty acids are included in the monograph. The essential fatty acid linoleic acid (18:2n-6) is not discussed in detail in this monograph. Oils rich in omega-6 fatty acids (e.g., corn oil) are not specifically discussed in this monograph. Oils rich in gamma-linolenic acid (18:3n-6), such as evening primrose oil, are not specifically discussed in this monograph.

evidence table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
 
ADHD (attention-deficit hyperactivity disorder) (Grade: C)
Both omega-3 (mainly docosahexaenoic acid) and omega-6 (mainly gamma-linolenic acid) fatty acids have been studied in patients with ADHD. Further research is needed before conclusions may be drawn.
Coordination disorders (Grade: C)
Both omega-3 (mainly docosahexaenoic acid) and omega-6 (mainly gamma-linolenic acid) fatty acids have been studied in patients with developmental disorders and ADHD. Further research is needed.
Eye disorders (meibomian gland dysfunction) (Grade: C)
Limited research suggests that a supplement containing omega-6 fatty acids may improve the symptoms of meibomian gland dysfunction. However, it is not clear if the supplement also contained other agents. Additional research on the use of omega-6 fatty acids alone is needed before conclusions may be drawn.
Healing after photorefractive keratectomy (Grade: C)
Limited research suggests that a supplement containing omega-6 fatty acids may improve the results of photorefractive keratectomy (a type of laser eye surgery). However, it is not clear if the supplement also contained other agents. Additional research on the use of omega-6 fatty acids alone is needed before conclusions may be drawn.
Multiple sclerosis (Grade: C)
Lower levels of certain omega-6 fatty acids were detected in the plasma of multiple sclerosis patients than in healthy controls. Additional research is required before conclusions may be drawn.