Public Health Nutrition

Research Paper

Plasma n-3 fatty acids and psychological distress in aboriginal Cree Indians (Canada)

Michel Lucasa1, Éric Dewaillya1a2 p1 c1, Carole Blancheta1, Suzanne Gingrasa1 and Bruce J Holuba3

a1 Public Health Research Unit, Laval University Medical Research Centre (CHUQ), Sainte-Foy, Québec, Canada

a2 Department of Social and Preventive Medicine, Laval University, Sainte-Foy, Québec, Canada

a3 Department of Human Biology and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada


Objective To examine the relationship between psychological distress (PD) and plasma n-3 long-chain (LC) PUFA, i.e. EPA, docosapentaenoic acid (DPAn-3) and DHA.

Design Population-based, cross-sectional Santé-Québec Health Survey (1991). Participants were categorized as high-level PD if they scored over the 80th percentile of the PD Index in the Santé-Québec Survey; non-distressed subjects were those who scored less than this cut-off. Associations between tertiles of n-3 fatty acids (FA) and the risk of high-level PD were expressed as odds ratios, with the lowest tertile as the reference group.

Setting Québec, Canada.

Subjects Data were analysed from a representative sample of 852 James Bay Cree Indian adults aged 18 years and over.

Results Proportions of n-3 FA were statistically significantly lower in the PD than in the non-distressed group. After adjustment for confounders, EPA was the only individual n-3 FA significantly associated with the risk of high-level PD. Combinations of EPA + DHA or EPA + DPAn-3 + DHA or the sum of n-3 were also associated with the risk of high-level PD. Compared with the lowest tertile of EPA + DHA, the OR for high-level PD was 0·89 (95 % CI 0·59, 1·36) for the second and 0·56 (95 % CI 0·32, 0·98) for the third tertile, after controlling for confounders.

Conclusions In the present retrospective, cross-sectional study, we found that proportions of n-3 LC PUFA in plasma phospholipids, markers of n-3 LC PUFA consumption from fish, were inversely associated with PD.

(Received June 19 2008)

(Accepted December 11 2008)

(Online publication February 26 2009)