Effects of Isoflavones on Gene-expression

NCT ID: NCT01232751

Last Updated: 2012-01-10

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 30 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2010-08-31
• Study Completion Date: 2011-10-31

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.

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

Conditions

Postmenopause

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Blinding Strategy: TRIPLE

Interventions

Isoflavone supplement

The participants will consume 2 times 2 supplements per day, which will lead to a daily dose of 114 mg. (HPLC analysis confirmed an aglycone isoflavone content of 28.41 mg per supplement)

Intervention Type: DIETARY_SUPPLEMENT

Other Intervention Names

Phytosoya forte (35mg) from the company Arkopharma

Eligibility Criteria

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)

• Minimum Eligible Age: 45 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: Yes

Sponsors

Wageningen University

OTHER

Sponsor Role: lead

Responsible Party

Lisette de Groot

(Vera van der Velpen)

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Pieter van 't Veer, Professor

Role: PRINCIPAL_INVESTIGATOR

Wageningen University

Locations

Wageningen University

Wageningen, Gelderland, Netherlands

Countries

Netherlands

References

van der Velpen V, Geelen A, Schouten EG, Hollman PC, Afman LA, van 't Veer P. Estrogen receptor-mediated effects of isoflavone supplementation were not observed in whole-genome gene expression profiles of peripheral blood mononuclear cells in postmenopausal, equol-producing women. J Nutr. 2013 Jun;143(6):774-80. doi: 10.3945/jn.113.174037. Epub 2013 Apr 24.

Reference Type: DERIVED

PMID: 23616509 (View on PubMed)

Other Identifiers

NL 32375.081.10

Identifier Type: -

Identifier Source: org_study_id