Brown Seaweed as a Breast Cancer Preventive

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Brown Seaweed as a Breast Cancer Preventive

Conditions
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Breast Cancer

Intervention / Treatment
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* Dietary Supplement: Seaweed and Soy Protein
* Dietary Supplement: Placebo and Soy Protein


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Arm 1 Seaweed and Soy Protein<br>Arm 1 5 g/d Seaweed for 6 wk, then 5 g/d Seaweed and Soy Protein for 1 wk | Dietary Supplement: Seaweed and Soy Protein<br>* 5 g/d Seaweed for 6 wks, followed by 5 g/d Seaweed + Soy Protein for 1 wk<br>* Other names: Alaria esculenta;|
| Experimental: Arm 2 Placebo and soy protein<br>Arm 2 5 g/d Placebo for 6 wk, then 5 g/d Placebo and Soy Protein for 1 wk | Dietary Supplement: Placebo and Soy Protein<br>* 5 g/d Placebo for 6 wks, followed by 5 g/d Placebo + Soy Protein for 1 wk<br>* Other names: Maltrin M100 maltodextrin (Grain Processing);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 | 14 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 | 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 | 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 | 14 wk | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Homocysteine, Insulin-like growth factor, Insulin-like growth factor binding protein, Serum estrogen, Urinary phytoestrogens, Thyroid hormones