Yes, technically, pure, uncontaminated oats are gluten-free. The U. S. Food and Drug Administration considers them a gluten-free grain under its gluten-free labeling regulations and only requires that packaged products with oats as an ingredient contain less than 20 parts per million of gluten overall.
However, like other grains, you should always use caution when it comes to oats. Even though oats are naturally gluten-free, a small portion of people with celiac disease still react to them. Some research suggests that a protein in oats can trigger a similar response to gluten, though it is thought to be a separate sensitivity.
Most of the concern about oats stems from the fact that mills that process oats also handle gluten-containing grains, creating a substantial risk for cross-contact. Oats without a gluten-free label are not considered safe for those who have celiac disease.
Specialty gluten-free oats are grown, harvested and processed in a way that keeps them away from other grains and the high risk of gluten contamination and are widely accepted as safe for those with celiac disease.
However, since the FDA gluten-free labeling rules were approved, a number of companies that include oats in their products labeled gluten-free have begun to use oats that are mechanically cleaned and separated to eliminate gluten, a practice that is allowed by the FDA. There is debate about whether these kinds of oats and the products in which they are used are safe for those who have celiac disease.
The North American Society for the Study of Celiac Disease released a statement on oats in the gluten-free diet that provides some guidance and AOAC International, an independent association that develops science-based analytical standards, has started work on standards for measuring gluten in oats.
For now, the best advice Beyond Celiac can offer is to be careful when introducing gluten-free oats into your diet, which includes speaking with your healthcare provider about this dietary change. There is no way to determine if you will react, so proceed with caution.
Be sure to use oats that are “pure, uncontaminated,” “gluten-free,” or “certified gluten-free.” Experts believe that up to 50g of dry gluten-free oats a day are considered safe. Check nutrition labels for portion size. People who develop any new symptoms after adding gluten-free oats to their diet should talk to their dietitian or doctor.