The Effect of Grape Seed Extract on Estrogen Levels of Postmenopausal Women

Overview

The role of estrogens in the pathogenesis of breast cancer has been well documented. This has led to the development of "Anti-Estrogens" (selective estrogens receptor modulators and Aromatase Inhibitors), used for treatment and prevention of breast cancer. These agents, however, have significant side effects, which are not acceptable to many healthy high-risk women. There is preliminary evidence that grape seed extract acts as "natural" aromatase inhibitor (1). This study has the potential to quantify the effectiveness of a natural substance that mimics the action of pharmaceutical aromatase inhibitors.

Full Title of Study: “The Effect of Grape Seed Extract on Estrogen Levels of Postmenopausal Women: A Pilot Study”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Treatment
    • Masking: None (Open Label)
  • Study Primary Completion Date: September 2011

Detailed Description

Early detection of breast cancer with screening mammography and the use of more effective medical therapies have led to a decrease in breast cancer mortality. However, breast cancer is still the second leading cause of cancer death in women (2). Therefore, the future lies in not only early detection but prevention of breast cancer. Currently available chemopreventive agents are associated with potentially serious side effects and can be quite costly, especially when taken for extended periods of time. Therefore, they are usually targeted only to women at high risk of disease. Identification of an inexpensive, efficacious preventive therapy with few or no side effects would represent a major advance in reducing the morbidity and mortality due to breast cancer. One exciting possibility is grape seed extract. Grapes and grape seeds contain procyanidins, a highly active subclass of flavonoids with actions similar to pharmaceutical aromatase inhibitors (AIs). These procyanidin dimers have been found to suppress estrogen biosynthesis both in vitro and in animal models (1). Based upon this knowledge we proposed this dose finding pilot study.

Interventions

  • Dietary Supplement: Grape Seed Extract
    • 200 mg dose daily for 12 weeks.
  • Dietary Supplement: Grape Seed Extract
    • 400 mg dose daily for 12 weeks.
  • Dietary Supplement: Grape Seed Extract
    • 600 mg dose daily for 12 weeks.
  • Dietary Supplement: Grape Seed Extract
    • 800 mg dose daily for 12 weeks.

Arms, Groups and Cohorts

  • Active Comparator: Grape Seed Extract # 1
    • 200 mg [1 pill]
  • Active Comparator: Grape Seed Extract # 2
    • 200 mg [2 pills]
  • Active Comparator: Grape Seed Extract # 3
    • 200 mg [3 pills]
  • Active Comparator: Grape Seed Extract # 4
    • 200 mg [4 pills]

Clinical Trial Outcome Measures

Primary Measures

  • To document that grape seed extract taken orally will decrease plasma estrogen levels (estrone (E1), estradiol (E2), and E1-conjugates) and increase precursor androgen levels (testosterone and androstenedione) in healthy postmenopausal women.
    • Time Frame: 12 weeks

Secondary Measures

  • To determine the most effective, well tolerated dose of grape seed extract resulting in a decrease in plasma estrogen levels (E1, E2, E1-conjugates) and increase in precursor androgens (testosterone and androstenedione).
    • Time Frame: 12 weeks

Participating in This Clinical Trial

Inclusion Criteria

  • Age 55 – 75 years – Able to understand and sign a consent form – Postmenopausal (no menstrual period for 1 year or more) – No personal cancer history (except for non-melanoma skin cancer) – No hormone replacement therapy or anti-estrogens within 6 months of baseline Exclusion Criteria:

  • Known allergy to grapes or grape products – Currently on ACE inhibitors, methotrexate, allopurinol, coumadin (Warfarin, Jantoven), heparin, clopidogrel (Plavix), or cholesterol lowering medication

Gender Eligibility: Female

Minimum Age: 55 Years

Maximum Age: 75 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • Mayo Clinic
  • Provider of Information About this Clinical Study
    • Principal Investigator: Dietlind Wahner-Roedler, Principal Investigator – Mayo Clinic
  • Overall Official(s)
    • Dietlind L. Wahner-Roedler, M.D., Principal Investigator, Mayo Clinic

References

Eng ET, Ye J, Williams D, Phung S, Moore RE, Young MK, Gruntmanis U, Braunstein G, Chen S. Suppression of estrogen biosynthesis by procyanidin dimers in red wine and grape seeds. Cancer Res. 2003 Dec 1;63(23):8516-22.

American Cancer Society. Cancer Facts and Figures 2005. Atlanta, GA: American Cancer Society; 2005.

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