High intake of dietary n-3 polyunsaturated fatty acids (PUFA) is associated with a decreased risk of ulcerative colitis (UC) and Crohn's disease (CD).
However, results have been heterogeneous suggesting that genetic variations in PUFA metabolism may modify this risk.
Professor Ashwin Ananthakrishnan and colleagues conducted a case–control study nested within 2 prospective cohorts, the Nurses' Health Study (NHS) and NHS II.
Among women providing blood or buccal cells for genotyping, the researchers confirmed new diagnoses of CD or UC.
Dietary intake was assessed 4 years before diagnosis.
|A high intake of n3:n6 PUFA demonstrated a trend toward reduced risk of UC|
|Inflammatory Bowel Disease|
Subjects were genotyped for single nucleotide polymorphisms at CYP4F3, FADS1, and FADS2 loci.
Conditional logistic regression models examined the interaction between genotype, n3:n6 PUFA intake and risk of CD and UC.
The research team included 101 CD and 139 UC patients matched to 495 controls.
The researchers found that a high intake of n3:n6 PUFA demonstrated a trend toward reduced risk of UC.
The team noted that a high n3:n6 PUFA intake was associated with a reduced risk of UC in individuals with the GG/AG genotype at a single nucleotide polymorphism in CYP4F3 but not those with the AA genotype.
No gene–diet interactions were noted for CD.
Professor Ananthakrishnan's team comments, "The association between dietary n3:n6 PUFA intake and risk of UC may be modified variants at CYP4F3."
"Further gene–environment studies of the association between diet and IBD risk are warranted."