title: Dietary exposure to polychlorinated biphenyls and risk of myocardial infarction - a population-based prospective cohort study.
abstract: BACKGROUND
  Fish consumption may promote cardiovascular health. The role of major food contaminants, such as polychlorinated biphenyls (PCBs) common in fatty fish, is unclear. We assessed the association between dietary PCB exposure and risk of myocardial infarction taking into account the intake of long-chain omega-3 fish fatty acids.
  
  
  METHODS
  In the prospective population-based Swedish Mammography Cohort, 33,446 middle-aged and elderly women, free from cardiovascular disease, cancer and diabetes at baseline (1997) were followed-up for 12 years. Validated estimates of dietary PCB exposure and intake of fish fatty acids (eicosapentaenoic acid and docosahexaenoic acid; EPA-DHA) were obtained via a food frequency questionnaire at baseline.
  
  
  RESULTS
  During follow-up 1386 incident cases of myocardial infarction were ascertained through register-linkage. Women in the highest quartile of dietary PCB exposure (median 286 ng/day) had a multivariable-adjusted RR of myocardial infarction of 1.21 (95% confidence interval [CI], 1.01-1.45) compared to the lowest quartile (median 101 ng/day) before, and 1.58 (95% CI, 1.10-2.25) after adjusting for EPA-DHA. Stratification by low and high EPA-DHA intake, resulted in RRs 2.20 (95% CI, 1.18-4.12) and 1.73 (95% CI, 0.81-3.69), respectively comparing highest PCB tertile with lowest. The intake of dietary EPA-DHA was inversely associated with risk of myocardial infarction after but not before adjusting for dietary PCB.
  
  
  CONCLUSIONS
  Exposure to PCBs was associated with increased risk of myocardial infarction, while some beneficial effect was associated with increasing EPA and DHA intake. To increase the net benefits of fish consumption, PCB contamination should be reduced to a minimum.
authors: Unit of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm, Sweden.
authors: Charlotte
authors: C
authors: Bergkvist
authors: Unit of Biochemical Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm, Sweden.
authors: Marika
authors: M
authors: Berglund
authors: Department of Risk and Benefit Assessment, National Food Agency, Box 622, SE-751 26 Uppsala, Sweden.
authors: Anders
authors: A
authors: Glynn
authors: Unit of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm, Sweden.
authors: Alicja
authors: A
authors: Wolk
authors: Unit of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm, Sweden. Electronic address: agneta.akesson@ki.se.
authors: Agneta
authors: A
authors: Åkesson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D015331:Cohort Studies; D004032:Diet; D004281:Docosahexaenoic Acids / Q000008:administration & dosage; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage; D005260:Female; D005399:Fishes; D005506:Food Contamination; D006801:Humans; D008875:Middle Aged; D009203:Myocardial Infarction / Q000139:chemically induced / Q000453:epidemiology* / Q000517:prevention & control; D011078:Polychlorinated Biphenyls / Q000008:administration & dosage / Q000506:poisoning*; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology
chemical_list: D015525:Fatty Acids, Omega-3; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; D011078:Polychlorinated Biphenyls
keywords: Diet; Long-chain n-3 fish fatty acids; Myocardial infarction; Polychlorinated biphenyls; Prospective cohort; Women