Breast Cancer
Conditions
Keywords
Homocysteine, Insulin-like growth factor, Insulin-like growth factor binding protein, Serum estrogen, Urinary phytoestrogens, Thyroid hormones
Brief summary
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
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.
Interventions
DIETARY_SUPPLEMENTSeaweed and Soy Protein
5 g/d Seaweed for 6 wks, followed by 5 g/d Seaweed + Soy Protein for 1 wk
DIETARY_SUPPLEMENTPlacebo and Soy Protein
5 g/d Placebo for 6 wks, followed by 5 g/d Placebo + Soy Protein for 1 wk
Sponsors
Susan G. Komen Breast Cancer Foundation
University of South Carolina
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 80 Years
Healthy volunteers
Yes
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Thyroid hormones affected by dietary seaweed and soy supplements | 14 weeks | 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 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Serum estrogen and urinary phytoestrogen concentrations affected by seaweed and soy | 14 wks | 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 |
| Serum antioxidant and homocysteine concentrations associated with seaweed and soy | 14 wks | 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 |
| Serum IGF-1 and IGFBP3 changes associated with seaweed and soy supplementation | 14 wk | 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 |
Countries
United States
Outcome results
None listed