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United States Department of Agriculture

Agricultural Research Service

Research Project: MICRONUTRIENT ROLES IN PHYSIOLOGY AND HEALTH Title: Effect of dietary fat and omega-3 fatty acids on urinary eicosanoids and sex hormone concentrations in postmenopausal women: a randomized controlled feeding trial

Authors
item Orr, Lindsay -
item Kurzer, Mindy -
item Thomas, William -
item Redmon, Bruce -
item Raatz, Susan

Submitted to: Nutrition and Cancer
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 3, 2011
Publication Date: August 15, 2011
Repository URL: http://handle.nal.usda.gov/10113/58226
Citation: Orr, L.R., Kurzer, M.S., Thomas, W., Redmon, B., Raatz, S.K. 2011. Effect of dietary fat and omega-3 fatty acids on urinary eicosanoids and sex hormone concentrations in postmenopausal women: a randomized controlled feeding trial. Nutrition and Cancer. 63(6):930–939.

Interpretive Summary: Increased sex hormone levels are related to increased breast cancer risk. Varying omega-3 fatty acid (n-3) intake may lead to changes in circulating sex hormones that reduce risk. To clarify effects of dietary fat and n-3 intake on breast cancer risk markers, circulating sex hormones and urinary eicosanoids were measured in response to controlled feeding of diets designed to increase plasma concentrations of n-3. A controlled cross-over feeding trial in 17 postmenopausal women was conducted using three diets: high fat(HF; 40% energy from fat),low fat(LF; 20% energy from fat)and low fat plus n-3 (LFn3; 20% of energy from fat plus 3% of energy from n-3) in 8-wk feeding periods. Plasma phospholipid fatty acids (PLFA), plasma sex hormones and urinary eicosanoids were measured in response to each diet. Plasma PLFA n-3 were increased with the LFn3 relative to HF and LF (P < 0.0001). Urinary prostaglandin E metabolite (PGE-M) increased with HF relative to LF and LFn3 (P = 0.02) and urinary 11-dehydro-thromboxane B2 (TxB-M) increased with HF (P = 0.01). Plasma estradiol (E2) was increased by HF (P = 0.03) and plasma follicle stimulating hormone (FSH) was increased by LF (P = 0.03). There was a trend for reduced estrone with LFn3 relative to HF and LF (P = 0.14). These results support a role of low fat diet and n-3 in reduction of breast cancer risk relative to a high fat diet.

Technical Abstract: Substantial evidence relates increased sex hormone concentrations with increased breast cancer risk. Varying omega-3 fatty acid (n-3) intake may lead to alterations in eicosanoid balance and subsequent changes in circulating sex hormones that reduce risk. To clarify effects of dietary fat and n-3 intake on breast cancer risk markers, circulating sex hormones and urinary eicosanoids were measured in response to controlled feeding of diets designed to increase plasma concentrations of n-3. A controlled cross-over feeding trial in 17 postmenopausal women was conducted using three diets: high fat (HF; 40% energy from fat), low fat (LF; 20% energy from fat) and low fat plus n-3 (LFn3; 20% of energy from fat plus 3% of energy from n-3) in 8-wk feeding periods. Plasma phospholipid fatty acids (PLFA), plasma sex hormones and urinary eicosanoids were measured in response to each diet. Plasma PLFA n-3 were increased with the LFn3 relative to HF and LF (P < 0.0001). Urinary prostaglandin E metabolite (PGE-M) increased with HF relative to LF and LFn3 (P = 0.02) and urinary 11-dehydro-thromboxane B2 (TxB-M) increased with HF (P = 0.01). Plasma estradiol (E2) was increased by HF (P = 0.03) and plasma follicle stimulating hormone (FSH) was increased by LF (P = 0.03). There was a trend for reduced estrone with LFn3 relative to HF and LF (P = 0.14). These results support a role of low fat diet and n-3 in reduction of breast cancer risk relative to a high fat diet.

Last Modified: 7/30/2014
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