title: Influence of food and lifestyle on the risk of developing inflammatory bowel disease.
abstract: BACKGROUND
  The Barwon area in Australia has one of the highest incidence rates of inflammatory bowel disease (IBD) and therefore is an ideal location to study the impact of environmental exposures on the disease's development.
  
  
  OBJECTIVE
  To study these exposures prior to the development of IBD in a population-based cohort.
  
  
  METHODS
  One hundred and thirty-two incident cases (81 Crohn disease (CD) and 51 ulcerative colitis (UC)) from an IBD registry and 104 controls replied to the International Organization of Inflammatory Bowel Diseases environmental questionnaire. This included 87 questions about pre-illness exposures that included childhood illnesses, vaccinations, breastfeeding, house amenities, pets and swimming, diet and smoking.
  
  
  RESULTS
  The factors associated with CD included smoking (odds ratio (OR): 1.42, confidence interval (CI): 1-2.02, P = 0.029); childhood events, including tonsillectomy (OR: 1.74, CI: 1.15-2.6, P = 0.003) and chicken pox infection (OR: 3.89, CI: 1.61-9.4, P = 0.005) and pre-diagnosis intake of frequent fast food (OR: 2.26, CI: 1.76-4.33, P = 0.003). In UC, the risk factors included smoking (OR: 1.39, CI: 1.1-1.92, P = 0.026) and pre-diagnosis intake of frequent fast food (OR: 2.91, CI: 1.54-5.58, P < 0.001), and high caffeine intake was protective (OR: 0.51, 95% CI: 0.3-0.87, P = 0.002). Other protective exposures for UC included high fruit intake (OR: 0.59, CI: 0.4-0.88, P = 0.003) and having pets as a child (OR: 0.36, CI: 0.2-0.79, P = 0.001).
  
  
  CONCLUSIONS
  This first Australian population-based study of environmental risk factors confirms that smoking, childhood immunological events and dietary factors play a role in IBD development; while high caffeine intake and pet ownership offer a protective effect.
authors.affiliation: Department of Gastroenterology, The University of Melbourne, St Vincent's Hospital, Melbourne, Victoria, Australia.
authors.forename: O
authors.identifier: http://orcid.org/0000-0003-3476-0422
authors.initials: O
authors.lastname: Niewiadomski
authors.affiliation: Gastroenterology Department, Royal Hobart Hospital, Hobart, Tasmania, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Studd
authors.affiliation: Gastroenterology Department, North West Regional Hospital, Burnie, Tasmania, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Wilson
authors.affiliation: Department of Gastroenterology, The University of Melbourne, St Vincent's Hospital, Melbourne, Victoria, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Williams
authors.affiliation: Gastroenterology Department, Barwon Health, Geelong, Victoria, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Hair
authors.affiliation: Gastroenterology Department, Barwon Health, Geelong, Victoria, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Knight
authors.affiliation: Gastroenterology Department, Barwon Health, Geelong, Victoria, Australia.
authors.forename: E
authors.initials: E
authors.lastname: Prewett
authors.affiliation: Gastroenterology Department, Barwon Health, Geelong, Victoria, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Dabkowski
authors.affiliation: Gastroenterology Department, Barwon Health, Geelong, Victoria, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Alexander
authors.affiliation: Gastroenterology Department, Barwon Health, Geelong, Victoria, Australia.
authors.forename: B
authors.initials: B
authors.lastname: Allen
authors.affiliation: Gastroenterology Department, Barwon Health, Geelong, Victoria, Australia.
authors.forename: D
authors.initials: D
authors.lastname: Dowling
authors.affiliation: Department of Gastroenterology, The University of Melbourne, St Vincent's Hospital, Melbourne, Victoria, Australia.
authors.forename: W
authors.initials: W
authors.lastname: Connell
authors.affiliation: Department of Gastroenterology, The University of Melbourne, St Vincent's Hospital, Melbourne, Victoria, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Desmond
authors.affiliation: Department of Gastroenterology, The University of Melbourne, St Vincent's Hospital, Melbourne, Victoria, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Bell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001315:Australia / Q000453:epidemiology; D016022:Case-Control Studies; D002644:Chickenpox / Q000453:epidemiology; D002648:Child; D004032:Diet; D057140:Fast Foods / Q000009:adverse effects; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology*; D008019:Life Style; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012042:Registries; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014068:Tonsillectomy / Q000706:statistics & numerical data; D055815:Young Adult
keywords: Crohn disease; aetiology; environmental factors; epidemiology; inflammatory bowel disease; ulcerative colitis