Effect of high omega‐3 fatty acid diet on markers of breast cancer risk in postmenopausal women

Abstract

ObjectiveThe primary objective is to determine whether diets designed to increase plasma omega‐3 fatty acid (n3) levels (a low fat diet, with or without n3), will affect sex hormone distribution in postmenopausal women in a direction associated with reduced risk of breast cancer.MethodsWe are conducting a well‐controlled feeding study to evaluate dietary fat and fatty acid effects. The diets tested in 8 week feeding periods include a "high risk" American diet (40% fat) (HF), a low fat diet (20% fat) (LF) and a low fat diet with 3% n3 (23% fat) (LFn3). Plasma estradiol (E2), estrone (E1), estrone sulfate (E1‐S), testosterone (T), androstenedione (AS), sex hormone binding globulin (SHBG), follicle stimulating hormone (FSH), dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEAS) from baseline and 8 weeks of each diet were analyzed by radio‐immunoassay for 10 participants.ResultsSHBG levels were significantly increased at 8 weeks with LFn3 compared to LF (p < 0.05), and there was a trend for decreased DHEAS level at 8 weeks with LFn3 compared to LF (p < 0.15). A trend for increased E2 was observed with HF compared to both LF and LFn3 at 8 weeks (p < 0.15).ConclusionsPreliminary data suggest that LFn3 alters estrogen metabolism in a direction associated with reducing breast cancer risk in postmenopausal women.This study was supported by DOD W81XWH‐06‐1‐0778, DOD W81XWH0410448, NIH/NCRR MO1‐00400.Grant Funding SourceDOD W81XWH‐06‐1‐0778, DOD W81XWH0410448, NIH/NCRR MO1‐00400