The hormone estrogen has positive benefits on the immune system of women. During menopause, the effects of aging and diminishing concentrations of estrogen may negatively impact the immune system. Soy isoflavones have both estrogenic and antioxidant properties so they may be beneficial to women during this stage of life.
A recent study evaluated the effects of soy isoflavones, both in soymilk and supplement form, on immunity and oxidative stress in postmenopausal women. Results from this placebo-controlled double blind study showed that soy isoflavones from either the soymilk or supplements were beneficial. Isoflavones increased the population of B-cells, important cells in the immune system, and decreased the plasma concentration of a compound whose high levels are an indicator of DNA damage. Soymilk and supplemental isoflavones may therefore be protective against DNA damage and improve immune function in postmenopausal women.
Source: Soy isoflavones modulate immune function in healthy postmenopausal women, Tracy A Ryan-Borchers, Jean Soon Park, Boon P Chew, Michelle K McGuire, Lisa R Fournier and Kathy A Beerman, American Journal of Clinical Nutrition, Vol. 83, No. 5, 1118-1125, May 2006
