title: Associations of dietary polychlorinated biphenyls and long-chain omega-3 fatty acids with stroke risk.
abstract: Little is known about joint exposure to polychlorinated biphenyls (PCBs) and long-chain omega-3 fatty acids [eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA)], through fish consumption, on cerebrovascular disease risk.
  
  
  
  To explore associations of dietary PCB exposure and EPA-DHA intake with risk of different stroke subtypes.
  
  
  
  This was assessed in the prospective population-based Cohort of Swedish Men including 39,948, middle-aged and elderly men, who were free of cardiovascular disease and cancer at baseline in 1997. Validated estimates of dietary PCBs and EPA-DHA were obtained via a food frequency questionnaire.
  
  
  
  During 12years of follow-up, 2286 and 474 incident cases of ischemic stroke and hemorrhagic stroke, respectively, were ascertained through register linkage. Dietary PCB exposure and EPA-DHA intake were associated with hemorrhagic stroke but not ischemic stroke. Men in the highest quartile of dietary PCB exposure (median 412ng/day) had a multivariable- and EPA-DHA-adjusted RR of hemorrhagic stroke of 2.77 [95% confidence interval (CI), 1.48-5.19] compared with men in the lowest quartile (median 128ng/day; p for trend <0.01). The corresponding RRs in men with and without hypertension were 5.45 (95% CI, 1.34-22.1) and 2.37 (95% CI 1.17-4.79), respectively. The multivariable- and PCB-adjusted RR of hemorrhagic stroke for the highest quartile of EPA-DHA intake (median 0.73g/day) versus the lowest quartile (median 0.18g/day) was 0.42 (95% CI, 0.22-0.79).
  
  
  
  Dietary PCB exposure was associated with an increased risk of hemorrhagic stroke, whereas a protective association was observed for dietary EPA-DHA intake.
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE 171 77, Stockholm, Sweden. Electronic address: maria.kippler@ki.se.
authors.forename: Maria
authors.initials: M
authors.lastname: Kippler
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE 171 77, Stockholm, Sweden. Electronic address: susanna.larsson@ki.se.
authors.forename: Susanna C
authors.initials: SC
authors.lastname: Larsson
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE 171 77, Stockholm, Sweden. Electronic address: marika.berglund@ki.se.
authors.forename: Marika
authors.initials: M
authors.lastname: Berglund
authors.affiliation: Department of Risk and Benefit Assessment, National Food Agency, Box 622, SE 751 26, Uppsala, Sweden. Electronic address: anders.glynn@slv.se.
authors.forename: Anders
authors.initials: A
authors.lastname: Glynn
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE 171 77, Stockholm, Sweden. Electronic address: alicja.wolk@ki.se.
authors.forename: Alicja
authors.initials: A
authors.lastname: Wolk
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE 171 77, Stockholm, Sweden. Electronic address: agneta.akesson@ki.se.
authors.forename: Agneta
authors.initials: A
authors.lastname: Åkesson
mesh_terms: D000368:Aged; D000818:Animals; D004032:Diet; D004281:Docosahexaenoic Acids / Q000032:analysis / Q000494:pharmacology; D015118:Eicosapentaenoic Acid / Q000032:analysis / Q000494:pharmacology; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D015525:Fatty Acids, Omega-3 / Q000032:analysis* / Q000494:pharmacology; D005260:Female; D005399:Fishes; D006801:Humans; D008297:Male; D008875:Middle Aged; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000633:toxicity; D011446:Prospective Studies; D012307:Risk Factors; D017747:Seafood / Q000032:analysis*; D020521:Stroke / Q000139:chemically induced / Q000453:epidemiology* / Q000517:prevention & control; D013548:Sweden
chemical_list: D015525:Fatty Acids, Omega-3; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; D011078:Polychlorinated Biphenyls
keywords: Hemorrhagic stroke; Ischemic stroke; Long-chain omega-3 fatty acids; Polychlorinated biphenyls