Celiac Disease and Gluten-Free Oats: A Canadian Position Based on a Literature Review

Table 2

Clinical studies of the effects of oats on adults with celiac disease from January 2008 to January 2015.

Reference authors, year of publication	Number of subjects tested	Oats exposure	Amount of oats	Lab tests	Biopsy	Dropout rate	Conclusion
Guttormsen et al., 2008, Norway [21]	82 subjects GFD with oat consumption; 54 subjects GFD without oats	2 years	Mean = 24 g/day (minimum 6 months)	Antiavenin IgA, anti-gliadin IgA, and TTG IgA	No biopsy	Not specified	Most adult CD patients can tolerate oats Ingestion of oats does not cause increased levels of IgA oats in CD patients with GFD; Purity of oats not verified
Sey et al., 2011, Canada [22]		3 months	50 g/day	TTG IgA	Duodenal biopsies before and after oat challenge (Marsh score): histology scores did not significantly change during oat challenge	One relapse occurred in a patient who became noncompliant with GFD	IgA TTG antibodies remained negative in all patients and the histology scores did not change. Support the safety of uncontaminated oats for patients with CD
Tuire et al., 2012, Finland [23]	96 (54%) with persistent IEL; 74 (42%) normal small intestinal mucosa; 7 (4%) villous atrophy	Mean = 11 years	Not specified	Endomysial IgA and TTG IgA	Consumption of oats was the only factor contributing to the persistent IEL		Despite excellent villous recovery, persistent IEL was common among CD patients on a long-term GFD. Consumption of oats was associated with persistent IEL; Purity of oats not verified.
Kaukinen et al., 2013, Finland [24]	36 no oat in GFD; 70 oats in GFD	Median = 5 years; Range = 0.5–8 years	Median = 20 g/day; Range = 1–100 g/day	Endomysial IgA and TTG IgA	Small-bowel mucosal biopsies were normal in 103 patients; 2 patients using oats and 1 patient not using oats had abnormal structure	None	Long-term consumption of pure oats proved to be safe for CD patients. Long-term regular follow-up is recommended
Hardy et al., 2015 [25]	(3 sources of oats assessed)	3 days	100 g/day	In vivo avenin-specific T cells responses	No biopsy	4 subjects did not complete the full 3-day challenge	34 patients reported no symptoms and 46 reported digestive symptoms.; Ingestion of 100 g of oats provides weak antigenic stimulation of blood avenin-specific T cells (<10% of CD patients) which is different from the antigenic stimulation observed with wheat, rye, and barley

Abs: antibodies; CD: celiac disease; GFD: gluten-free diet; IEL: intraepithelial lymphocytes; IgA: immunoglobulin A; IgG: immunoglobulin G; TTG: tissue transglutaminase; GFD-std: standard GFD without oats; GFD-oats: GFD with uncontaminated oats.