Effect of vitamin E on severity and duration of cyclic mastalgia: A systematic review and meta-analysis.

Objectives: A systematic review was conducted to assess the effect of vitamin E on the severity and duration of Cyclic Mastalgia compared to vitamin B6, fish oil, herbal medicines and placebo.

Design: A systematic review and meta-analysis of clinical trials.

Methods: A search was carried out in PubMed, Cochrane Library, Embase, Scopus and Google Scholar and Persian databases for articles published from 1980 to 2018. The data obtained were analyzed in RevMan and reported in forest plots. The Odds Ratio (OR) was used to find the effect for the dichotomous data and the Standardized Mean Difference (SMD) for the continuous data. The heterogeneity of the studies was assessed using I and the Random Effects Model was used instead of the Fixed Effects Model if I>25%.

Results: A total of 1051 titles and abstracts were extracted. Fourteen articles ultimately remained, and 11 of them were entered into the meta-analysis. The meta-analysis showed significant differences between vitamin E and placebo in the severity (SMD=-0.51; 95% CI=-0.21 to -0.82) and duration (MD=-1.47; 95% CI=-0.91 to -2.57) of cyclic mastalgia, although herbal medicines had a greater effect on the severity of mastalgia than vitamin E (SMD = 0.51, 95% CI = 0.06 to 0.96).

Conclusion: Although herbal medicines are more effective than vitamin E, vitamin E reduces both the severity and duration of the disorder compared to placebos, which only reduce its severity, and can therefore be considered a treatment with minimum side-effects. Due to the high heterogeneity of the studies, the researchers recommend further research on the subject using a standard tool based on the CONSORT statement.