SOY MILK AND THE MENSTRUAL CYCLE
Can regular consumption of soy milk cause changes in a woman's menstrual cycle?
—Laura Sullivan, MD, Downey, Calif.
Soy milk contains relatively low concentrations of plant estrogens (isoflavones). Therefore, it is extremely unlikely that regular consumption of soy milk will alter normal menstrual cyclicity. In one study in which Asian soy foods containing about 32 mg of isoflavones were ingested each day for three months, participants experienced no change in cycle length during the seven months they were followed.
—Daniel R. Mishell Jr, MD (104-2)