For the past month I have significantly increased the amount of soy in my diet. I am also on the pill (birth control). I know both soy and the pill contain hormones. This month, my period came earlier than it usually does (3 days). Could my increased soy intake have caused a hormonal imbalance? Is it dangerous?

It is highly unlikely that an increase in dietary soy intake will disrupt your monthly menstrual cycle. The compound soy contains is estrogen-like, but it is not estradiol. The plant sources of estrogen (isoflavones) in soy are weak estrogens, only 1/100th to 1/1000th the activity of synthetic estrogens you get in birth control pills. A moderate amount of soy containing foods should not be a problem. Research, thus far, by no means identifies the isoflavones in soy as dangerous. Nevertheless, there is a dearth of information and research in women that addresses your question. If you have a significant change in your menstrual cycle and are concerned about it please do not hesitate to contact you health care practitioner, it may be something else entirely. Your HCP will know how long have you been on birth control pills, the prescription formula, and exactly how much soy you are ingesting. Getting your period three days early is within a “normal” variation of the menstrual cycle. If you have dietary questions regarding your new food plan, Student Health Service employs a nutritionist who is available to you. Call 4-2091 to make an appointment.