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

Abstract

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 four 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 as well as 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 (PUFA) were not associated with risk of CD or UC. However, greater intake of long-chain n-3 PUFA was associated with a trend towards lower risk of UC (Hazard ratio (HR) 0.72, 95% CI 0.51 – 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 – 1.92). Conclusion A high intake of dietary long-chain n-3 PUFA 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.

Pouring fuel on the fire: Th17 cells, the environment, and autoimmunity

“…However, addition of polyunsaturated fatty acids (PUFAs), which have been shown to mitigate obesity-associated metabolic pathology, results in decreased colitis severity in mice placed on a high-fat diet that otherwise would exacerbate disease, and this correlates with decreased levels of a number of Th17-related cytokines (101)(102)(103). Interestingly, observational data from the Nurse's Health Study suggest a possible correlation between dietary PUFA intake and a reduced risk of ulcerative colitis, whereas high intake of trans-unsaturated fats was associated with an increased risk of developing ulcerative colitis (104). Thus, both obesity and dietary fat intake can alter the production of cytokines involved in Th17 differentiation and potentially predispose to the development of autoimmunity.…”

Dietary Patterns and Risk of Inflammatory Bowel Disease in Europe

“…High intakes of linoleic acid, 6 animal proteins, 7 as well as low intakes of docosohexaenoic acid (DHA) have been associated with a higher risk of UC. High intakes of animal protein 7 as well as low intakes of fiber and fruit 8,9 and DHA 10 have been associated with a greater risk of CD.…”

Potential Impact of Diet on Treatment Effect from Anti-TNF Drugs in Inflammatory Bowel Disease

“…Findings from the European Investigation into Cancer and Nutrition (EPIC) Study and the Nurses' Health Study (NHS) are particularly noteworthy because of their large well-characterized cohorts [16][17][18][19][20][21][22][23][24][25][26][27][28][29]. These studies have investigated the involvement of dietary factors such as dietary patterns, vitamin D, dietary fibre, zinc, dairy products, n-3 and n-6 polyunsaturated fatty acids (PUFA), and protein, 3 of 15 particularly animal protein, in IBD development [14,[16][17][18][19][20][21][22][23][24][25][26][27][28][29]. The increases in IBD seen in developing countries as they adopt a Western lifestyle [5], and the high incidence among immigrants coming from low to high incidence areas, strongly suggest the involvement of other environmental factors such as lifestyle factors in disease aetiology [31].…”