Long-chain polyunsaturated fatty acid intake and its relationship to red blood cell and plasma long-chain polyunsaturated fatty acids in women at high risk for breast cancer

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.