Menopausal symptoms: from soy isoflavones to combined soy-exercise interventions
Diet and physical activity affect menopausal symptoms. We aimed to review recent evidence based on clinical trials and meta-analysis on the effect of soy isoflavones on menopausal symptoms and the potential synergistic effect of soy consumption and exercise on menopausal women. Many studies have investigated the effect of soy isoflavones on menopausal symptoms and the data indicates that equol status is the main determinant for efficacy. Despite this, it is well known that exercise changes microbiota composition. Only one study has investigated the combined intervention with soy and exercise and reported that soy extract did not improve the positive impact of mixed exercise training. Moreover, soy proteins have anti-nutrient effects on iron and zinc, and negatively influence protein digestibility. In conclusion, although isoflavones could improve menopausal symptoms in equol-producers, postmenopausal women doing exercise should avoid high soy consumption. Furthermore, a recent prospective study has suggested caution against the use of supplements containing soy isoflavones in women with a family history of breast cancer.