Table 1
Question	Conclusion	Study Limitation
How does the inclusion of oats in a dietary pattern for people with celiac disease impact effectiveness and acceptability of the dietary pattern?	Studies have shown that incorporating oats uncontaminated with wheat, barley or rye, into a gluten-free dietary pattern for people with celiac disease, at intake levels of approximately 50 g dry oats per day, is generally safe and improves compliance. However, many studies report that the introduction of oats may result in gastrointestinal symptoms such as diarrhea and abdominal discomfort. These symptoms tend to be the primary reason for study subject withdrawal. Additional adverse effects that have been reported include dermatitis herpetiformis, villous atrophy and an increased density of intraepithelial lymphocytes, indicating that some persons with celiac disease may be unable to tolerate oats. Since limited research has been conducted on the similarities among those with adverse reactions to oats, further research is needed in this area. Further research is also needed regarding the contamination of oats by wheat, barley and rye. Grade III	Potential limitations of the studies evaluated for this analysis include insufficient duration of follow-up and inadequate sample size. Eleven in vivo studies were assessed. Only two of these had study periods greater than one year. Therefore, oats may have been consumed for periods of time insufficient to cause immunologic effects. Six of the studies had very small sample sizes (less than 20 participants). Therefore, these studies may not have included persons sensitive to the oat prolamin avenin. In addition, only two of the studies assessed the safety of oat consumption in children.
How does the inclusion of wheat starch-based gluten-free foods (as defined by the Codex Alimentarius), in a dietary pattern for people with celiac disease, impact the effectiveness and acceptability of their dietary pattern (as compared to a gluten-free diet comprised solely of naturally gluten-free foods, as defined by Codex)?	Studies have shown that both natural and wheat starch-based gluten-free diets produce similar histological and clinical recovery in people with celiac disease. Overall compliance with a gluten-free diet may be more important than the specific type of diet followed (i.e., natural or wheat starch-based), as evidenced by the incomplete bowel mucosal recovery and positive serology generally seen in those study subjects with dietary lapses. Further research regarding the acceptability of wheat starch-based gluten-free foods and the threshold level of tolerance for gluten is needed. Grade III	Potential limitations of the studies evaluating the inclusion of wheat starch in a gluten-free dietary pattern include variations in the amount of wheat starch ingested, whether individuals were consuming wheat starch prior to the study period and the amount of gliadin in the wheat starch-based gluten-free dietary pattern. In two studies, the amount of gluten-free flours consumed were measured; in two other studies, the number of servings of wheat starch-based products consumed were self-reported; in another study, the exact amount of gliadin in the gluten-free flour was calculated. Therefore, it may be difficult to determine the exact amount of gliadin consumed in these studies. One study used exclusion criteria of prior consumption of wheat starch, while four studies did not. More research is needed to determine a safe and acceptable threshold of gliadin.