Effects of Isoflavones on Gene-expression (ISO)

Wageningen University

Status: Completed

Conditions: Postmenopause

Treatments: Dietary Supplement: Isoflavone supplement

Study type: Interventional

Funder types: Other

Identifiers

NCT01232751

NL 32375.081.10

Details and patient eligibility

About

Alleged benefits experienced by the consumption of soy in Asian countries have been attributed to the isoflavone content of soy products. Amongst other benefits, isoflavones are believed to relieve menopausal symptoms and are therefore often consumed in supplement form in Western countries. These supplements contain relatively high amounts of isoflavones, and the question is if these concentrations still exert beneficial effects or whether negative effects become dominant. Therefore, the investigators will study the effect of intake of one dose of isoflavones, as compared to placebo, for eight weeks on gene-expression in Peripheral Blood Mononuclear Cells (PBMCs) in post-menopausal, equol-producing women.

Full description

Primary Objective: to determine the effect of intake of one dose of isoflavones, as compared to placebo, for eight weeks on gene-expression in Peripheral Blood Mononuclear Cells (PBMCs) in post-menopausal, equol-producing women.

Secondary Objectives: to determine the association between isoflavone plasma levels and gene-expression in PBMCs; to determine the variation of isoflavone plasma levels between subjects after intake of isoflavones for four and eight weeks; to explore whether PBMC gene-expression markers identified after 8 weeks isoflavone intervention are already present after 4 weeks intervention; to explore whether the severity of previous menopausal complaints is related to the effect of isoflavones on PBMC gene-expression; and to explore the association between isoflavone levels in plasma and spot urine.

Study design: Double-blind placebo controlled crossover intervention study

Study population: Thirty-six healthy females, 45-70 years, post-menopausal and equol-producing

Intervention: Two intervention periods of eight weeks with a isoflavone supplement or a placebo and a washout period of 8 weeks in between.

Main study parameters/endpoints: The main study parameter is gene-expression in PBMCs measured by micro-arrays.

Enrollment: 30 patients

Sex: Female

Ages: 45 to 70 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• 45-70 years
• Equol producer
• Post-menopausal (Follicle Stimulating Hormone (FSH) >40 UI/L) or
• menstrual cycle absent for more than 1 year.

Exclusion criteria

• current use of contraceptives containing hormones
• current use of hormone replacement therapy
• regular soy product use (more than once a week)
• regular isoflavone supplement use (more than once a week)
• current use of medication containing sex hormones or sex hormone-triggering compounds
• current use of anti-inflammatory medicines
• use of antibiotics in the past 6 months
• severe heart disease
• thyroid disorders
• removed thyroid gland
• complete ovariectomy
• prior diagnosis of cancer in medical history
• alcohol and drug abuse
• current smoker
• Body Mass Index (BMI) >35 kg/m2
• allergy to soy (products)