LONG-CHAIN POLYUNSATURATED FATTY ACID INTAKE AND ITS RELATIONSHIP TO RED BLOOD CELL AND SERUM LONG-CHAIN POLYUNSATURATED FATTY ACIDS IN WOMEN AT HIGH RISK FOR BREAST CANCER

Abstract

A higher ratio of omega-6 (n-6) to omega-3 (n-3) long chain polyunsaturated fatty acids (LCPUFA) in breast tissue triglyceride (TG) has been correlated with increased risk of developing breast cancer. Before dietary recommendations can be made regarding n-3 PUFAs in relation to breast cancer risk reduction, a noninvasive biomarker must be identified so that further research can be done in larger populations. This pilot study compared LCPUFA intake to red blood cell (RBC) and plasma LCPUFAs in women at high risk for breast cancer. Women were screened (n=260) at the University of Kansas Medical Center Breast Cancer Prevention Center high-risk breast clinic. Eighty-six were eligible and of these 48 (58%) completed and returned the diet history questionnaire (DHQ). The mean age of the subjects was 47 ± 9.9 years, and the mean body mass index (BMI) was 25 ± 4.4. The mean 5-year Gail risk was 2.7 ± 2.2%. Twenty-two (48%) of the subjects were premenopausal and 24 (52%) were postmenopausal. Fifteen (33%) were taking an n-3 PUFA supplement (fish oil or flaxseed). Mean dietary intakes were 9.94 ± 4.9 g n-6/d and 1.26 ± 0.6 g n-3/d, with an n-6:n-3 ratio of approximately 9:1. Total phospholipid (PL) n-6 in RBC and plasma was 27.74 ± 3.44% and 33.92 ± 3.72%, respectively. Total PL n-3 in RBC and plasma was 5.59 ± 1.7% and 4.06 ± 1.19%, respectively. Plasma TG docasahexaenoic acid (DHA) was highly correlated with n-3 intake (r=0.53, p=<0.05). Women at the University of Kansas Medical Center Breast Cancer Prevention Center consume an n-6:n-3 LCPUFA ratio typical of the US population. RBC PL n-3s were significantly correlated to n-3, adding to the validity of both intake and biomarker assessment. Additional analyses will address whether breast tissue TG n-3 or n-6:n-3 ratio reflects a blood biomarker of n-3 or n-3:n-6 ratio.