Introduction Dietary fats influence intestinal inflammation and regulate mucosal immunity. Data on the association between dietary fat and risk of Crohn's disease and ulcerative colitis are limited and conflicting.
Dr Ashwin Ananthakrishnan and colleagues from Massachusetts, USA conducted a prospective study of women enrolled in the Nursesí Health Study cohorts.
Diet was prospectively ascertained every 4 years using a validated semi-quantitative food frequency questionnaire.
Self-reported Crohn's disease and ulcerative colitis were confirmed through medical record review.
|Greater intake of long-chain n-3 PUFAs was associated with a trend towards lower risk of ulcerative colitis|
The team examined the effect of energy-adjusted cumulative average total fat intake, and specific types of fat and fatty acids on the risk of Crohn's disease and ulcerative colitis using Cox proportional hazards models adjusting for potential confounders.
Among 170,805 women, the researchers confirmed 269 incident cases of Crohn's disease, and 338 incident cases of ulcerative colitis over 26 years, and 3,317,338 person-years of follow-up.
The team found that 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 Crohn's disease or ulcerative colitis.
However, the researchers noted that greater intake of long-chain n-3 PUFAs was associated with a trend towards lower risk of ulcerative colitis.
In contrast, high long-term intake of trans-unsaturated fatty acids was associated with a trend towards an increased incidence of ulcerative colitis.
Dr Ananthakrishnan's team commented, "A high intake of dietary long-chain n-3 PUFAs may be associated with a reduced risk of ulcerative colitis."
"In contrast, high intake of trans-unsaturated fats may be associated with an increased risk of ulcerative colitis."