Plasma phospholipid fatty acid composition as a biomarker of habitual dietary fat intake in an ethnically diverse cohort Allison M. Hodge a,b, *, Julie A. Simpson a,b , Robert A. Gibson c,d , Andrew J. Sinclair e , Maria Makrides c,f , Kerin O’Dea g , Dallas R. English a,b , Graham G. Giles a,b a Cancer Epidemiology Centre, The Cancer Council Victoria, Melbourne, Australia b School of Population Health, University of Melbourne, Melbourne, Australia c Child Health Research Institute, Women’s and Children’s Hospital, Adelaide, Australia d Flinders Medical Centre, Adelaide, Australia e School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Australia f University of Adelaide Department of Paediatrics, Women’s and Children’s Hospital, Adelaide, Australia g Department of Medicine, University of Melbourne, St. Vincents Hospital, Melbourne, Australia Received 13 November 2005; received in revised form 7 April 2006; accepted 10 April 2006 KEYWORDS Plasma phospholipids; Diet; Fatty acids; Food frequency questionnaire; Biomarker; Middle-aged adults Abstract Background and aim: As an evaluation of fatty acid intake measure- ment, our aim was to examine associations between diet and plasma phospholipid (PL) fatty acids, and whether these were modified by age, sex, country of birth, fasting status, use of cholesterol-lowering medication, body size, chronic disease and other lifestyle factors. Methods and results: Cross-sectional analysis of plasma PL fatty acid composition and dietary fatty acid intake over 12 months from a 121-item food frequency ques- tionnaire (FFQ) in 4439 men and women aged 40e69 years, born in Australia, Greece or Italy. Crude correlation coefficients ranged from 0.18 to 0.40; and cor- rected correlation coefficients from 0.38 to 0.78 for total monounsaturated, poly- unsaturated, n-6, n-3 fatty acids, oleic acid, linoleic acid, EPA and DHA. Weaker associations were observed for other fatty acids. The associations did not vary significantly by fasting status, use of lipid lowering medication or alcohol intake, but for some fatty acids did vary by sex, age, body mass index, country of birth, smoking and previous heart attack or diabetes. * Corresponding author. Cancer Epidemiology Centre, The Cancer Council Victoria, 1 Rathdowne Street, Carlton, Victoria 3053, Australia. Tel.: þ61 3 9635 5222; fax: þ61 3 9635 5330. E-mail address: allison.hodge@cancervic.org.au (A.M. Hodge). 0939-4753/$ - see front matter ª 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.numecd.2006.04.005 Nutrition, Metabolism & Cardiovascular Diseases (2007) 17, 415e426 www.elsevier.com/locate/nmcd