Research Investigation of Soy and Estrogen

Anxiety is a common, but understudied complaint in midlife women, and increases during the menopausal transition. Changes in estrogen are dramatic during the menopausal transition, and indirect data suggest a potential role for estrogen, particularly estrogen receptor beta, in mediating anxiety. Two subtypes of the estrogen receptor, alpha and beta (ER-alpha and ER-beta), appear to be critically involved in the expression of anxiety in females. Compounds that preferentially target ER-beta, including plant-derived estrogens (phytoestrogens), lower both anxiety behaviors and responsivity to discrete stressors, including social stress, in laboratory animals. The primary aim of this proposal is to carry out the first study to translate these preclinical studies to humans by comparing and contrasting of the effects of phytoestrogens, estradiol, and placebo on daily anxiety and responses to moderate psychosocial stress in the laboratory. As second focus is emotional and non-emotional cognition. This focus stems from evidence that estrogen can protect against the negative impact of glucocorticoids on memory. These aims will be accomplished in a 12-week randomized placebo-controlled, clinical trial comparing three treatments: 1) a phytoestrogen supplement (Novasoy® 400, 55 mg tablet twice daily); 2) oral estradiol (1 mg/daily; plus 10 mg medroxyprogesterone acetate at study end 10 for 10 days); and 3) placebo (identical appearing tablets twice daily). The enrollment target is 120 healthy women in the menopausal transition (40 per group). To measure anxiety, women will complete the State-Trait Anxiety Inventory (STAI). To measure responsivity to psychosocial stress, parallel forms of the Trier Social Stress Test, a widely used laboratory induction that involves unanticipated public speaking and social evaluative fear, will be used to induce moderate psychosocial stress before and after treatment. At both laboratory sessions, measures of subjective stress (STAI), cortisol, and emotional memory performance will be obtained at multiple points during a control condition and during the psychosocial stress condition. Lastly, we will measure treatment effects on measures of verbal memory.

Inclusion criteria

• Female
• Perimenopausal as defined by the Stages of Reproductive Aging Workshop (STRAW) criteria, specifically in either of the two following stages: a) early transition defined as changes in cycle length of seven days or more in either direction in consecutive cycles or b) late transition defined as > 60 days amenorrhea and FSH > 40 IU/mL
• Intact uterus/ovaries (i.e. no surgical menopause)
• at least 1 self-reported hot flash per week
• Estrogen therapy not contraindicated
• Able to give informed consent
• Age between 40 and 65 years
• English as first and primary language

Exclusion criteria

• Positive pregnancy test or breastfeeding (pregnancy tests will be given to all women)
• Obesity > 35 BMI
• Previous history of endometrial hyperplasia/neoplasia
• Previous history of cancers of the breast or reproductive tract
• History of presence of myocardial infarction (MI) or stroke
• Current clinical diagnosis or a diagnosis within the past year of an anxiety disorder, severe recurrent depression, or severe psychiatric disturbance
• History of head injury with more than 60 minutes loss of consciousness
• History of neurological condition affecting cognitive function (e.g., brain tumor, multiple sclerosis)
• History of developmental disability affecting cognitive function (e.g., mental retardation, attention deficit)
• Current use of CNS-acting medication (e.g., antidepressants, anxiolytics, diphenhydramine)
• History or presence of cerebrovascular accident, sickle cell anemia
• History of alcohol or drug abuse as defined by DSM criteria
• Abnormal vaginal bleeding of undetermined cause
• Untreated or uncontrolled hypertension defined as systolic blood pressure greater than 165 mm hg or diastolic blood pressure greater than 95 mm hg
• Concurrent administration of medication containing estrogen, progestin, SERM within four months of enrollment
• Concurrent administration of medication containing St. John's wort, bisphosphonates, or dietary phytoestrogens within one month of enrollment
• History of migraine associated with hormone use
• History or presence of deep vein thrombosis, thrombophlebitis or thromboembolic disorder
• Current participation in any other clinical trial within 30 days of enrollment
• Smoker
• Diabetes
• Premature ovarian failure (defined as having last menstrual period before age 40)
• Abnormal PAP smear in previous year
• Abnormal mammogram in previous year
• Vegans (vegetarians who tend to consume greater than average doses of phytoestrogens)
• Allergy to soy (affects ~1% of people in the United States; reactions are typically mild)
• Symptomatic fibroids (significant size or significant menstrual changes)
• Menorrhagia
• Lactose intolerant