Association between high dietary intake of the n−3 polyunsaturated fatty acid docosahexaenoic acid and reduced risk of Crohn's disease

Abstract

SummaryBackgroundThere are plausible mechanisms for how dietary docosahexaenoic acid (DHA), an n−3 polyunsaturated fatty acid, could prevent Crohn's disease (CD).AimTo conduct a prospective study to investigate the association between increased intake of DHA and risk of CD.MethodsOverall, 229 702 participants were recruited from nine European centres between 1991 and 1998. At recruitment, dietary intakes of DHA and fatty acids were measured using validated food frequency questionnaires. The cohort was monitored through to June 2004 to identify participants who developed incident CD. In a nested case–control analysis, each case was matched with four controls; odds ratios (ORs) were calculated for quintiles of DHA intake, adjusted for total energy intake, smoking, other dietary fatty acids, dietary vitamin D and body mass index.ResultsSeventy‐three participants developed incident CD. All higher quintiles of DHA intake were inversely associated with development of CD; the highest quintile had the greatest effect size (OR = 0.07; 95% CI = 0.02–0.81). The OR trend across quintiles of DHA was 0.54 (95% CI = 0.30–0.99, Ptrend = 0.04). Including BMI in the multivariate analysis, due to its correlation with dietary fat showed similar associations. There were no associations with the other dietary fatty acids studied.ConclusionThere were inverse associations, with a biological gradient between increasing dietary docosahexaenoic acid intakes and incident Crohn's disease. Further studies in other populations should measure docosahexaenoic acid to determine if the association is consistent and the hypothesis tested in randomised controlled trials of purely docosahexaenoic acid supplementation.

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.…”

What is known about the mechanisms of dietary influences in Crohn's disease?

“…A multicenter European study of 229,702 participants was the first to look at the relationship between dietary intake of the PUFA, docosahexaenoic acid (DHA), and CD. A significant inverse relationship between the development of CD and dietary intake of DHA was found [11]. However the Nurses' Health Study I and II did not find any association with long-term intake of total fat, saturated fats, or unsaturated fats with risk for CD [12].…”

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].…”