Brown Seaweed as a Breast Cancer Preventive

Phase 2CompletedNCT01204957

University of South Carolina33 enrolled

Overview

Japanese postmenopausal women in Japan have about one ninth the rate of American postmenopausal women. Rates of breast cancer double even after just ten years among Japanese women who migrate to the US. Diet is thought to be an important factor, and the investigators were interested in whether dietary seaweed, with and without soy supplements, could influence known biomarkers of breast cancer risk in American women.

33 healthy postmenopausal women were randomized to 6 wk seaweed then 1 wk seaweed plus soy or 6 wk placebo then 1 wk placebo plus soy. Blood and urine samples were collected at the end of each treatment period and analyzed for estrogen, homocysteine, antioxidants, insulin-like growth factors and thyroid hormones. Urine was analyzed for phytoestrogens and iodine.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

QUADRUPLE

Enrollment

Conditions

Breast Cancer

Interventions

Seaweed and Soy ProteinDIETARY_SUPPLEMENT

5 g/d Seaweed for 6 wks, followed by 5 g/d Seaweed + Soy Protein for 1 wk

Placebo and Soy ProteinDIETARY_SUPPLEMENT

5 g/d Placebo for 6 wks, followed by 5 g/d Placebo + Soy Protein for 1 wk

Eligibility

Sex: FEMALEMin age: 18 YearsMax age: 80 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Postmenopausal (self-reported cessation of menstruation 1 y prior to enrollment) * If breast cancer survivor, all therapy completed at least 6 months prior to enrollment * Agreed to eat their normal diet, avoiding seaweeds and phytoestrogen-rich foods, * Restricting alcoholic intake to #2 drinks (24 g alcohol)/wk -Continuing habitual intake of vitamins, supplements, and medications during the study. - Exclusion Criteria: * No allergies to seaweed, soy, shellfish, or iodine * No current use of tobacco; * No thyroid dysfunction or treatment within the previous 5 y; * Negative thyroid peroxidase antibodies as determined by screening; * No hormone replacement therapy or for breast cancer survivors, no chemotherapy or radiation treatments within the preceding 6 mo * No history of cancer (other than breast cancer) * No current gastrointestinal disorders or diabetes; omnivorous eating habits, including meat and dairy products at least twice/wk * No oral antibiotics, iodine containing medications, or corticosteroids treatment within the previous 3 mo.

Locations (1)

University of Massachusetts

Worcester, Massachusetts, United States

Outcomes

Primary Outcomes

Thyroid hormones affected by dietary seaweed and soy supplements

6 wk seaweed followed by 1 wk seaweed plus soy; Or 6 wk placebo followed by 1 wk soy 3 wk washout period then crossover to alternate arm

Time frame: 14 weeks

Secondary Outcomes

Serum estrogen and urinary phytoestrogen concentrations affected by seaweed and soy

6 wk seaweed then 1 wk seaweed plus soy; OR 6 wk placebo then 1 wk soy 3 wk washout period, then crossover to alternate arm

Time frame: 14 wks

Serum antioxidant and homocysteine concentrations associated with seaweed and soy

6 wks seaweed followed by 1 wk seaweed plus soy OR 6 wk placebo followed by 1 wk soy 3 wk washout period, then crossover to alternate arm

Time frame: 14 wks

Serum IGF-1 and IGFBP3 changes associated with seaweed and soy supplementation

6 wk seaweed then 1 wk seaweed plus soy OR 6 wk placebo then 1 wk soy plus placebo 3 wk washout then crossover to alternate arm

Time frame: 14 wk

Data from ClinicalTrials.gov

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