The Effect of Isoflavone Supplement Intake on Gene-expression in Postmenopausal Women
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Wageningen University
- Enrollment
- 30
- Locations
- 1
- Primary Endpoint
- Gene-expression measured by micro-arrays
Study Overview
Brief Summary
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.
Detailed 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.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Masking
- Triple (Participant, Investigator, Outcomes Assessor)
Eligibility Criteria
- Ages
- 45 Years to 70 Years (Adult, Older Adult)
- Sex
- Female
- Accepts Healthy Volunteers
- Yes
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)
Outcomes
Primary Outcomes
Gene-expression measured by micro-arrays
Time Frame: after 8 weeks of exposure to the placebo
Gene expression changes will be assessed in PBMCs using whole genome Affymetrix microarrays. The gene expression changes after exposure to the isoflavone supplement will be compared to the changes after exposure to the placebo.
Gene-expression measured by micro-arrays
Time Frame: gene-expression after 8 weeks of exposure to the isoflavone supplement
Gene expression changes will be assessed in PBMCs using whole genome Affymetrix microarrays. The gene expression changes after exposure to the isoflavone supplement will be compared to the changes after exposure to the placebo.
Secondary Outcomes
- Isoflavone levels in plasma and spoturine(after 8 weeks of exposure to the placebo)
- Confirmation of gene-expression with quantitative real time polymerase chain reaction (QPCR)(after 8 weeks of exposure to the placebo)
- Isoflavone levels in plasma and spoturine(after 0 weeks of exposure to the isoflavone supplement)
- Isoflavone levels in plasma and spoturine(after 4 weeks of exposure to the isoflavone supplement)
- Isoflavone levels in plasma and spoturine(after 8 weeks of exposure to the isoflavone supplement)
- Isoflavone levels in plasma and spoturine(after 0 weeks of exposure to the placebo)
- Isoflavone levels in plasma and spoturine(after 4 weeks of exposure to the placebo)
- Confirmation of gene-expression with quantitative real time polymerase chain reaction (QPCR)(after 0 weeks of exposure to the isoflavone supplement)
- Confirmation of gene-expression with quantitative real time polymerase chain reaction (QPCR)(after 4 weeks of exposure to the isoflavone supplement)
- Confirmation of gene-expression with quantitative real time polymerase chain reaction (QPCR)(after 0 weeks of exposure to the placebo)
- Confirmation of gene-expression with quantitative real time polymerase chain reaction (QPCR)(after 8 weeks of exposure to the isoflavone supplement)
- Confirmation of gene-expression with quantitative real time polymerase chain reaction (QPCR)(after 4 weeks of exposure to the placebo)
Investigators
Lisette de Groot
(Vera van der Velpen)
Wageningen University