Overview of the Effect of Herbal Medicines and Isoflavones on the Treatment of Cognitive Function

OBJECTIVES: The current overview aimed to present the effect of herbal medicines on cognitive function among menopausal women. METHODS: Two separate authors performed systematic search of the 3 databases of (the MEDLINE Scopus and the Cochrane Central Register Trials) from inception to January 2018. Methodological quality of each study was assessed using the AMSTAR. RESULTS: According to 2 reviews, soy seems to be effective in enhancing summary cognitive function and visual memory. The effect of isoflavones on cognition was affected by treatment duration as six weeks of treatment improved some dimensions of cognitive parameters, including mental flexibility and planning, and longer treatment period (6 months) improved category digit span test, digit symbol test, and visual scanning test score. The effect of phytoestrogen on cognitive function of menopausal women might be altered age, gender, ethnicity, menopausal status, dosage, and length of treatment, types of cognitive test, location, types of soy, and types of phytoestrogen. Combination of Gingko with ginseng could not improve sustained attention, episode memory, category generation or frontal lobe function. Gingko biloba had no significant effect on planning, memory and sustained attention, except for its limited effect on mental flexibility in late menopause. In addition, other herbal medicines like black cohosh showed no effective beneficial. CONCLUSIONS: Phytoestrogen, soy and isoflavones might have a limited beneficial effect on some aspects of cognition. The phytoestrogens affecting cognition might be modified by age, gender, ethnicity, menopausal status, dosage, and length of treatment, types of cognitive test, location, types of soy, and types of phytoestrogen.