Is there a beneficial effect of gamma-linolenic acid supplementation on body fat in postmenopausal hypertensive women? A prospective randomized double-blind placebo-controlled trial
This was a prospective, double-blind, placebo-controlled, randomized study involving 96 postmenopausal women. Participants were divided into two groups either receiving 1,000 mg of borage oil rich in gamma-linolenic acid + vitamin E (drug) or only vitamin E (placebo) capsules for 6 months. They were followed up monthly to assess the impact on systemic blood pressure and body composition. To verify group homogeneity, Fisher's exact and Student t tests were performed. To evaluate differences in various parameters between the two groups and at various times, repeated measuresanalysis of variance was performed, with Bonferroni correction.
RESULTS:
The power of the test was calculated based on the difference in the mean systolic blood pressure between baseline and after 6 months of treatment in the placebo group and in the drug group. A 92.9% test power was found with a 95% confidence interval. There was a significant reduction in the systolic and diastolic pressure as well as a significant change in waist-hip ratio (P < 0.01) in the drug group as compared with the placebo group.
CONCLUSIONS:
Supplementation with borage oil rich in gamma-linolenic acid had significant beneficial short-term effects without showing any adverse effect. There remains a need for further studies to evaluate long-term benefits.