The purpose of this study is to examine the way soy consumption affects menopausal symptoms in middle-aged Japanese women.

For the past 20 years, Japanese women have reported fewer menopausal symptoms than their North American counterparts. One explanation for the disparity is the differences in diet. Evidence suggests that Japanese women consume large amounts of soy, a phytoestrogen that is structurally similar to the hormone estrogen. However, there is a lack of menopause-related research data from non-Western populations. This study will be a long-term observation of the effects of soy consumption in menopausal Japanese women.

This study will last 6 months. Participants will complete a dietary log and a menopausal symptom checklist daily. There will be three or four study visits. During these visits, participants will complete a diet questionnaire, have a blood sample collected, and be interviewed about their menopausal symptoms. Six months after study completion, participants will be sent a questionnaire about any recent menopausal symptoms they may have experienced.

Inclusion Criteria:

• Japanese resident
• Menopausal

Exclusion Criteria:

• Hysterectomy, removal of ovaries, or tubal ligation with subsequent menstrual changes
• Hormones for menopause or birth control pills within 5 years of study entry
• Recent major illness
• Medication that could affect naturally-produced hormones