title: Relationship between erythrocyte omega-3 content and obesity is gender dependent.
abstract: Epidemiological evidence of an inverse association between consumption of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) and obesity has been conflicting, even though studies in animal models of obesity and limited human trials suggest that LC n-3 PUFA consumption may contribute to weight loss. We used baseline data from a convenience sample of 476 adults (291 women, 185 men) participating in clinical trials at our Centre to explore relationships between erythrocyte levels of LC n-3 PUFA (a reliable indicator of habitual intake) and measures of adiposity, viz. body mass index (BMI), waist circumference (WC) and body fat (BF) assessed by dual-energy X-ray absorptiometry. Means ± SD of assessments were BMI: 34 ± 7 and 31 ± 5 kg/m2; WC: 105 ± 16 and 110 ± 13 cm; BF: 48 ± 5 and 35% ± 6% in women and men respectively. Erythrocyte levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were similar in men and women while docosapentaenoic acid (DPA) was higher and EPA + DHA (Omega-3 Index) slightly lower in men than in women. Both DHA and EPA + DHA correlated inversely with BMI, WC and BF in women while DPA correlated inversely with BF in men. Quartile distributions and curvilinear regression of the Omega-3 Index versus BMI revealed a steep rise of BMI in the lower range of the Omega-3 Index in women, but no association in men. Thus the results highlight important gender differences in relationships of specific LC n-3 PUFA in erythrocytes to markers of adiposity. If these reflect causal relationships between LC n-3 PUFA consumption and risk of obesity, gender specific targeted interventions should be considered.
authors.affiliation: Nutritional Physiology Research Centre, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. peter.howe@newcastle.edu.au.
authors.forename: Peter R C
authors.initials: PR
authors.lastname: Howe
authors.affiliation: Nutritional Physiology Research Centre, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. Jon.Buckley@unisa.edu.au.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Buckley
authors.affiliation: Nutritional Physiology Research Centre, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. karen.murphy@unisa.edu.au.
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Murphy
authors.affiliation: Nutritional Physiology Research Centre, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. tpettman@unimelb.edu.au.
authors.forename: Tahna
authors.initials: T
authors.lastname: Pettman
authors.affiliation: Nutritional Physiology Research Centre, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. catherine.milte@deakin.edu.au.
authors.forename: Catherine
authors.initials: C
authors.lastname: Milte
authors.affiliation: Nutritional Physiology Research Centre, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. alison.coates@unisa.edu.au.
authors.forename: Alison M
authors.initials: AM
authors.lastname: Coates
mesh_terms: D015502:Absorptiometry, Photon; D050154:Adiposity; D000328:Adult; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D003430:Cross-Sectional Studies; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000097:blood*; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000097:blood*; D004912:Erythrocytes / Q000737:chemistry*; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D055105:Waist Circumference
chemical_list: D005395:Fish Oils; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid