Gamma-Linolenic Acid

Complementary Prescriptions’ gamma-linolenic acid (GLA) caps are now available in our new Liquid-Fill Capsules (LF Caps^™) and are formulated with black currant seed oil (BCSO), which replaces the borage oil used in the past. Black currant seed oil has an excellent fatty acid profile that includes gamma-linolenic acid, alpha-linolenic acid and the omega-3 fatty acid stearidonic acid. Due to its fatty acid content, black currant seed oil is a potent suppressor of inflammation¹ and an ideal choice for anyone searching for a high-quality GLA supplement.

Black currant seed oil exerts beneficial effects on the immune system, partly through its ability to down regulate prostaglandin E(2). The age-associated increase in production of prostaglandin E(2), a hormone-like substance, contributes to the decline in T cell-mediated immune function with age. To determine if black currant seed oil could prevent this decrease in immune function, researchers conducted a randomized, double-blind, placebo-controlled study to examine the effect of 2 months of black currant seed oil supplementation on the immune response of 40 healthy subjects aged 65 and older.² Black currant seed oil improved a number of markers of immunity in the subjects and significantly reduced prostaglandin E(2) production compared to the placebo group, leading the study authors to conclude, “BCSO has a moderate immune-enhancing effect attributable to its ability to reduce prostaglandin E(2) production.”

Gamma-Linolenic Acid

Black currant seed oil contains an abundant amount of gamma-linolenic acid. Dietary sources of GLA are uncommon and some individuals are unable to convert linoleic acid from the diet into gamma-linolenic acid, especially if they are zinc deficient, indicating that there is a great need for supplementation with this nutrient.

GLA has been shown to inhibit inflammatory responses by regulating inflammatory mediators such as NF-kappaB.³ GLA also upregulates prostaglandin E(1). A shortage of PGE1 can contribute to cramping and heavy blood loss experienced by many menstruating women.⁴

Furthermore, GLA exerts heart-protective effects. In an animal study, researchers found that GLA attenuated the formation of atherosclerotic plaques, inhibited the level of serum triglycerides, oxidized LDL cholesterol and markers of oxidation, leading them to conclude, “GLA might significantly attenuate the development of atherosclerosis in rats fed with high lipid diet through improving the antioxidation capacity of the body.”⁵

In cell culture studies, GLA also has triggered apoptosis (programmed cell death) in human leukemia cell lines⁶ and has inhibited tumor growth, cell cycle progression and angiogenesis in glioma cells.⁷ In one recent in vitro study, GLA was found to enhance the response of multi-drug-resistant leukemia cells to anticancer drugs.⁸

Stearidonic Acid

Black currant seed oil also is a rich source of stearidonic acid (SDA), a naturally occurring omega-3 polyunsaturated fatty acid that may have similar biological properties to eicosapentaenoic acid (EPA) derived from fish oil.⁹

In animals, stearidonic acid has been found to increase levels of EPA in the red blood cells and heart.¹⁰ Stearidonic acid also is a powerful inhibitor of inflammation that can suppress the expression of the inflammatory cyclooxygenase-2 (COX-2) enzyme.¹¹

Additionally, it has been shown to inhibit platelet aggregation, the process by which blood cells coagulate, indicating it has a role to play in heart health.¹²

Conclusion

The newly reformulated GLA caps, now available as LF Caps with black currant seed oil, are rich in both GLA and stearidonic acid, both anti-inflammatory components shown to play a role in myriad aspects of health. GLA caps can support immunity and heart health and inhibit inflammatory factors such as the COX-2 enzyme. These fatty acids, therefore, can become an important part of a supplement regimen.

References

1. Tate GA, Zurier RB. Suppression of monosodium urate crystal-induced inflammation by black currant seed oil. Agents Actions. 1994 Nov;43(1-2):35-8.

2. Wu D, Meydani M, Leka LS, Nightingale Z, Handelman GJ, Blumberg JB, Meydani SN. Effect of dietary supplementation with black currant seed oil on the immune response of healthy elderly subjects. Am J Clin Nutr. 1999 Oct;70(4):536-43.

3. Chang CS, Sun HL, Lii CK, Chen HW, Chen PY, Liu KL. Gamma-Linolenic Acid Inhibits Inflammatory Responses by Regulating NF-kappaB and AP-1 Activation in Lipopolysaccharide-Induced RAW 264.7 Macrophages. Inflammation. 2009 Oct 20. Published Online Ahead of Print.

4. Smith OP, Jabbour HN, Critchley HO. Cyclooxygenase enzyme expression and E series prostaglandin receptor signalling are enhanced in heavy menstruation. Hum Reprod. 2007 May;22(5):1450-6.

5. Shi LM, Ge HT, Kong XQ, Cai YF, Li PF, Liu ZL, Kong LD. Zhongguo Zhong Yao Za Zhi. [Effects of gamma linolenic acid on atherosclerosis induced by cholesterol-rich diet in rats] [Article in Chinese]. 2008 Dec;33(23):2808-12.

6. Ge H, Kong X, Shi L, Hou L, Liu Z, Li P. Gamma-linolenic acid induces apoptosis and lipid peroxidation in human chronic myelogenous leukemia K562 cells. Cell Biol Int. 2009 Mar;33(3):402-10.

7. Miyake JA, Benadiba M, Colquhoun A. Gamma-linolenic acid inhibits both tumour cell cycle progression and angiogenesis in the orthotopic C6 glioma model through changes in VEGF, Flt1, ERK1/2, MMP2, cyclin D1, pRb, p53 and p27 protein expression. Lipids Health Dis. 2009 Mar 17;8:8.

8. Kong X, Ge H, Chen L, Liu Z, Yin Z, Li P, Li M. Gamma-linolenic acid modulates the response of multidrug-resistant K562 leukemic cells to anticancer drugs. Toxicol In Vitro. 2009 Jun;23(4):634-9.

9. Whelan J. Dietary stearidonic acid is a long chain (n-3) polyunsaturated fatty acid with potential health benefits. J Nutr. 2009 Jan;139(1):5-10.

10. Harris WS, DiRienzo MA, Sands SA, George C, Jones PG, Eapen AK.Stearidonic acid increases the red blood cell and heart eicosapentaenoic acid content in dogs. Lipids. 2007 Apr;42(4):325-33.

11. Horia E, Watkins BA. Comparison of stearidonic acid and alpha-linolenic acid on PGE2 production and COX-2 protein levels in MDA-MB-231 breast cancer cell cultures. J Nutr Biochem. 2005 Mar;16(3):184-92.

12. Kockmann V, Spielmann D, Traitler H, Lagarde M. Inhibitory effect of stearidonic acid (18:4 n-3) on platelet aggregation and arachidonate oxygenation. Lipids. 1989 Dec;24(12):1004-7.