GLA: Omega-6 Fatty Acid
(gamma-linolenic acid)

DESCRIPTION/FUNCTION

• GLA is a derivative of the essential fatty acid, linoleic acid. Essential fatty acids (EFAs) are precursors of the hormone-like eicosanoids (prostaglandins, thromboxanes, leukotrienes) that participate in the regulation of blood pressure, heart rate, vascular dilation, blood clotting, lipolysis, immune response, and the central nervous system.

DRI (RDA or AI for Adults)

• None.
• As linoleic acid (precursor to GLA):
  • Males: 19-50 (17 g); 51 and older (14 g).
  • Females: 19-50 (12 g); 51 and older (11 g).
  • Pregnancy/Lactation: 13 g.

MAJOR SOURCES

• Black currant seed oil, borage seed oil, evening primrose oil.

MAINTENANCE/THERAPEUTIC RANGE

• 100 mg to 500 mg of GLA.

POSSIBLE THERAPEUTIC APPLICATIONS

• Cancer (breast; when taken with tamoxifen)
• Coronary heart disease
• Diabetes (neuropathy)
• Eczema
• Fibrocystic breasts
• High blood pressure
• High triglycerides
• Inflammation
• Osteoarthritis
• Premenstrual syndrome
• Rheumatoid arthritis

COMMENTS

• Most research has been done on borage and primrose oils. The three primary sources of GLA have varying concentrations of it: evening primrose oil (9-10%), black current seed oil (12-14%), borage seed oil (20-24%). Taking GLA is not likely to increase arachidonic acid (AA) levels, since most GLA from supplements is converted to dihomo-gamma linolenic acid (DGLA), and then to prostaglandin E1 (PGE1), a beneficial prostaglandin. DGLA actually competes with AA, reducing inflammation.