title: Polyunsaturated fatty acid interactions and breast cancer incidence: a population-based case-control study on Long Island, New York.
abstract: OBJECTIVE
  Experimental studies demonstrate that ω-3 polyunsaturated fatty acids (PUFAs) inhibit inflammatory eicosanoids generated by ω-6 PUFAs. Epidemiologic studies on dietary ω-3 PUFA intake show consistent inverse associations with breast cancer incidence among Asian populations, where ω-3, relative to ω-6, intake is high. In contrast, associations are inconsistent among Western populations, where intake of ω-3, relative to ω-6, is low. We hypothesized that examining interactions between ω-3 and ω-6 would help elucidate the PUFA-breast cancer association in the United States.
  
  
  METHODS
  In a Long Island, New York, population-based study of 1463 breast cancer cases and 1500 controls, we estimated multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression to examine interactions between ω-3 and ω-6 intake.
  
  
  RESULTS
  We observed a super-additive interaction (relative excess risk due to interaction = 0.41; 95% confidence interval = 0.06-0.76) between ω-3 and ω-6 intake in association with breast cancer incidence, although the CIs for the joint exposure of low ω-3/high ω-6 compared to high ω-3/low ω-6 intake were wide (odds ratio = 1.20; 95% confidence interval = 0.85-1.69).
  
  
  CONCLUSIONS
  Breast cancer risk reduction may be possible for U.S. women with dietary consumption of higher ω-3, which has anti-inflammatory properties, in concert with lower ω-6, which induces inflammation. Replication from future U.S.-based investigations is needed.
authors.affiliation: Department of Epidemiology, University of North Carolina, Chapel Hill. Electronic address: khankari@email.unc.edu.
authors.forename: Nikhil K
authors.initials: NK
authors.lastname: Khankari
authors.affiliation: Department of Nutrition, University of North Carolina, Chapel Hill.
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Bradshaw
authors.affiliation: Department of Epidemiology and Biostatistics, University of South Carolina, Columbia.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Steck
authors.affiliation: Department of Epidemiology and Biostatistics, Indiana University, Bloomington, IN.
authors.forename: Ka
authors.initials: K
authors.lastname: He
authors.affiliation: Department of Epidemiology, University of North Carolina, Chapel Hill.
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Olshan
authors.affiliation: Department of Environmental Health, Columbia University, New York, NY.
authors.forename: Jing
authors.initials: J
authors.lastname: Shen
authors.affiliation: Department of Population Health, New York University, New York; Department of Environmental Medicine, New York University, New York.
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Ahn
authors.affiliation: Department of Population Health, New York University, New York; Department of Environmental Medicine, New York University, New York.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Health Studies and Comprehensive Cancer Center, University of Chicago, Chicago, IL.
authors.forename: Habibul
authors.initials: H
authors.lastname: Ahsan
authors.affiliation: Department of Epidemiology, Columbia University, New York, NY.
authors.forename: Mary Beth
authors.initials: MB
authors.lastname: Terry
authors.affiliation: Department of Preventive Medicine, Mount Sinai School of Medicine, New York, NY.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Teitelbaum
authors.affiliation: Department of Epidemiology, Columbia University, New York, NY; Department of Medicine, Columbia University, New York, NY.
authors.forename: Alfred I
authors.initials: AI
authors.lastname: Neugut
authors.affiliation: Department of Environmental Health, Columbia University, New York, NY.
authors.forename: Regina M
authors.initials: RM
authors.lastname: Santella
authors.affiliation: Department of Epidemiology, University of North Carolina, Chapel Hill.
authors.forename: Marilie D
authors.initials: MD
authors.lastname: Gammon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000178:diet therapy* / Q000453:epidemiology / Q000517:prevention & control*; D016022:Case-Control Studies; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage* / Q000097:blood*; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage* / Q000097:blood*; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D009518:New York / Q000453:epidemiology; D016017:Odds Ratio; D018570:Risk Assessment; D017747:Seafood; D055815:Young Adult
chemical_list: D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6
keywords: Breast neoplasms; Polyunsaturated fatty acids; Seafood