Table 4.
Studies outlining the effects of supplementing dietary gamma-linolenic acid on changes in plasma/serum phospholipid arachidonic acid level
| Author, (reference) | Study design | Subjects | Diet length | GLA source, amount supplemented (g/d) | Δ AA (%) change | Comments |
|---|---|---|---|---|---|---|
| Ebden [52] | Double-blind intervention | N = 6 | 8 weeks | Efamol oil (0.36) | 6.1 (N.S.) | No crossover with placebo. Subjects were asthmatics used medication or bronchodilator. |
| Thavonen [29] | Randomized, double-blind crossover | N = 15 | 3 weeks | Black current seed oil (0.38) | 3.7 (N.S.) | Subjects aged 55-75 years old |
| Theis [45] | Double-blind parallel interventions | N = 8 | 12 weeks | GLA-rich triacylglycerol capsules (0.77) | 27 (p < 0.05) | Subjects consumed capsules for 12 weeks. AA changed only on 12th week. |
| Yaqoob [34] | Double-blind parallel intervention | N = 8 | 12 weeks | Evening primrose oil (1.06) | 14 (N.S.) | |
| Mills [28] | Randomized double-blind parallel intervention | N = 10 | 28 days | Borage oil (1.30) | 12 (p < 0.05) | AA data available for only pre and post intervention (28 days) |
| Miles [27] | Randomized double-blind intervention | N = 8-12 | 12 weeks | Borage oil capsules (2.00) | 15 (p < 0.05) | Consumed capsules for 12 weeks. AA only increased after the 8th week, no difference after 8th week. |
| Johnson [53] | Pre-post intervention | N = 5 | 3 weeks | Ultra-GLA capsules (6.00) | 31 (p < 0.05) |
Percent change (±) from baseline in AA that is significant is identified with (p < 0.05). Percent change (±) from baseline in AA that is not significant is denoted by N.S.
Abbreviations: AA, arachidonic acid; GLA, gamma-linolenic acid