title: Determinants of the omega-3 index in a Mediterranean population at increased risk for CHD.
abstract: The omega-3 index, defined as the sum of EPA and DHA in erythrocyte membranes expressed as a percentage of total fatty acids, has been proposed as both a risk marker and risk factor for CHD death. A major determinant of the omega-3 index is EPA+DHA intake, but the impact of other dietary fatty acids has not been investigated. In a cross-sectional study on 198 subjects (102 men and 96 women, mean age 66 years) at high cardiovascular risk living in Spain, the country with low rates of cardiac death despite a high prevalence of cardiovascular risk factors, dietary data were acquired from FFQ and blood cell membrane fatty acid composition was measured by GC. The average consumption of EPA+DHA was 0·9 g/d and the mean omega-3 index was 7·1 %. In multivariate models, EPA+DHA intake was the main predictor of the omega-3 index but explained only 12 % of its variability (P < 0·001). No associations with other dietary fatty acids were observed. Although the single most influential determinant of the omega-3 index measured here was the intake of EPA+DHA, it explained little of the former's variability; hence, the effects of other factors (genetic, dietary and lifestyle) remain to be determined. Nevertheless, the high omega-3 index could at least partially explain the paradox of low rates of fatal CHD in Spain despite a high background prevalence of cardiovascular risk factors.
authors: Lipid Clinic, Endocrinology and Nutrition Service, Institut d'Investigacions Biomèdiques August Pi Sunyer, Unitat de Lípids, Hospital Clinic, Villarroel 170, 08036 Barcelona, Spain. asala@clinic.ub.es
authors: Aleix
authors: A
authors: Sala-Vila
authors: William S
authors: WS
authors: Harris
authors: Montserrat
authors: M
authors: Cofán
authors: Ana M
authors: AM
authors: Pérez-Heras
authors: Xavier
authors: X
authors: Pintó
authors: Rosa M
authors: RM
authors: Lamuela-Raventós
authors: Maria-Isabel
authors: MI
authors: Covas
authors: Ramon
authors: R
authors: Estruch
authors: Emilio
authors: E
authors: Ros
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002462:Cell Membrane / Q000378:metabolism; D003430:Cross-Sectional Studies; D004041:Dietary Fats / Q000008:administration & dosage / Q000097:blood*; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000097:blood*; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000097:blood*; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006331:Heart Diseases / Q000097:blood / Q000209:etiology* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015596:Nutrition Assessment; D012307:Risk Factors; D013030:Spain; D011795:Surveys and Questionnaires
chemical_list: D015415:Biomarkers; D004041:Dietary Fats; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid