Gut 63:776-784 doi:10.1136/gutjnl-2013-305304
  • Inflammatory bowel disease
  • Original article

Long-term intake of dietary fat and risk of ulcerative colitis and Crohn's disease

  1. Andrew T Chan1,4
  1. 1Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
  2. 2Division of Gastroenterology and Nutrition, Children's Hospital Boston and Harvard Medical School, Boston, Massachusetts, USA
  3. 3Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
  4. 4Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
  5. 5Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts, USA
  1. Correspondence to Dr Ashwin N Ananthakrishnan, Massachusetts General Hospital Crohn's and Colitis Center, 165 Cambridge Street, 9th Floor, Boston, MA 02114, USA; aananthakrishnan{at}
  • Received 18 May 2013
  • Revised 12 June 2013
  • Accepted 14 June 2013
  • Published Online First 4 July 2013


Introduction Dietary fats influence intestinal inflammation and regulate mucosal immunity. Data on the association between dietary fat and risk of Crohn's disease (CD) and ulcerative colitis (UC) are limited and conflicting.

Methods We conducted a prospective study of women enrolled in the Nurses’ Health Study cohorts. Diet was prospectively ascertained every 4 years using a validated semi-quantitative food frequency questionnaire. Self-reported CD and UC were confirmed through medical record review. We examined the effect of energy-adjusted cumulative average total fat intake and specific types of fat and fatty acids on the risk of CD and UC using Cox proportional hazards models adjusting for potential confounders.

Results Among 170 805 women, we confirmed 269 incident cases of CD (incidence 8/100 000 person-years) and 338 incident cases of UC (incidence 10/100 000 person-years) over 26 years and 3 317 338 person-years of follow-up. Cumulative energy-adjusted intake of total fat, saturated fats, unsaturated fats, n-6 and n-3 polyunsaturated fatty acids (PUFAs) were not associated with risk of CD or UC. However, greater intake of long-chain n-3 PUFAs was associated with a trend towards lower risk of UC (HR 0.72, 95% CI 0.51 to 1.01). In contrast, high long-term intake of trans-unsaturated fatty acids was associated with a trend towards an increased incidence of UC (HR 1.34, 95% CI 0.94 to 1.92).

Conclusions A high intake of dietary long-chain n-3 PUFAs may be associated with a reduced risk of UC. In contrast, high intake of trans-unsaturated fats may be associated with an increased risk of UC.