By Upasana Abbott, NOW Quality Department
Primrose oil is valued for its gamma–linolenic acid (GLA; 18:3 omega-6) content. GLA is claimed to be effective in maintaining healthy inflammatory pathways and normalizing skin, nerve, and cellular health (McDonald and Fitzpatrick, 1998). GLA-rich oils are heart healthy, anti-aging, and liver supporting (Broadhurst and Winther, 2000).
In our diets, GLA is obtained from the conversion of the dietary precursor linoleic acid via the action of delta-6-desaturase enzyme. However, impairment of the delta-6-desaturase activity may result in the functional deficiency of GLA and leads to health issues (Wu and Meydani, 1996). Supplementation with GLA helps in supporting the body's ability to maintain health, especially in the areas noted above.
At NOW Foods, Primrose oil is analyzed for its GLA content by performing gas chromatography (GC) of methyl esters of fatty acids. We use this method to confirm the identity of Primrose Oil by its unique fatty acid profile and measure the amount of GLA present in it. This is achieved by separating GLA from other fatty acids, especially Linoleic and Linolenic acids. Linoleic and Linolenic acids are also present in common oils such as soybean oil, flax oil, and walnut oil but GLA is unique to Primrose and some other special oils. The GLA content is accurately measured by using an internal standards technique.
All these steps are taken to assure that our customers get what they are buying Evening Primrose Oil for: Authentic Primrose Oil with a GLA content over 9% by weight.
Broadhurst, C.L., and Winther, M. (2000). Evening Primrose Oil: pharmacological and clinical applications. In G. Mazza. And B.D. Oomah (Eds.), Herbs, botanicals and teas as functional foods and nutraceuticals (pp 213-264). Lancaster, PA: Technomic Publishing Co., Inc.
Manku, M.S. A comparison of GLC and HPLC methods for determining fatty acid composition of evening primrose and soybean oil. J. Chromatographic Science (1983) 21(8): 367-369
McDonald, B.E., and Fitzpatrick, K. (1998). Designer Vegetable Oils. In G. Mazza (Ed). Functional foods, biochemical and processing aspects (pp. 265-291). Lancaster, PA:Technomic Publishing Co., Inc.
Wu, D. and Meydani, S.N. (1996). γ-Linolenic acid and immune function. In Y.S. Huang, and D.E.Mills (Eds.), γ-Linolenic acid: metabolism and its roles in nutrition and medicine (pp.106-117), Champaign, IL: AOCS Press