Dietary fiber is associated with serum sex hormones and insulin-related peptides in postmenopausal breast cancer survivors.
OBJECTIVE
To measure the association between dietary fiber intake and eleven hormones and peptides in postmenopausal breast cancer survivors.


METHODS
Intake of fiber from food and supplements was measured two to three years after breast cancer diagnosis in 493 postmenopausal women from three western states. Concurrently, a fasting blood sample was obtained for assay of estrone, estradiol, free estradiol, testosterone, free testosterone, dehydroepiandrosterone sulfate, sex hormone-binding globulin (SHBG), leptin, C-peptide, insulin-like growth factor-1 (IGF1), and IGF-binding protein-3. Adjusted means of these hormones and peptides were calculated for categories of fiber intake.


RESULTS
High intake of dietary fiber was significantly (P<or=0.05) associated with low serum levels of estradiol and free estradiol and with high serum levels of IGF1. The combination of high dietary fiber intake and use of fiber supplements was additionally associated with low serum levels of C-peptide. The magnitude of the difference in hormone/peptide values, comparing high fiber intake to low fiber intake, varied from 16 to 28%, and the associations were independent of multiple confounding variables.


CONCLUSIONS
High fiber diets may be beneficial to postmenopausal breast cancer survivors due to fiber's favorable influence on sex hormones and peptides known to affect breast cancer prognosis.
New Mexico Tumor Registry, MSC 11 620, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA. swayne@salud.unm.edu
Sharon J
SJ
Wayne
Marian L
ML
Neuhouser
Cornelia M
CM
Ulrich
Carol
C
Koprowski
Kathy B
KB
Baumgartner
Richard N
RN
Baumgartner
Anne
A
McTiernan
Leslie
L
Bernstein
Rachel
R
Ballard-Barbash
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000473:pathology; D002096:C-Peptide / Q000097:blood*; D015331:Cohort Studies; D004043:Dietary Fiber; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D008875:Middle Aged; D017698:Postmenopause; D011446:Prospective Studies; D018426:SEER Program; D017741:Survivors
D002096:C-Peptide; D004043:Dietary Fiber; D012739:Gonadal Steroid Hormones; D007328:Insulin