What's the Deal with Oats?

WHAT’S THE DEAL WITH OATS?

For people with celiac disease, oats are considered a high-risk grain. This is because oats are often exposed to wheat, barley, and rye—the three gluten-containing grains—throughout farming and processing.

Most experts recommend choosing only Purity Protocol oats or certified gluten-free oats. Even then, a small percentage of people with celiac disease still react to oats, and they’re usually advised to avoid oats entirely, regardless of gluten-free labeling.

Why Oats Are Tricky

Commodity (conventional) oats can come into contact with gluten at many steps:

• Seed sourcing

• Crop rotation

• Harvesting equipment

• Transportation

• Sorting and milling

• Final packaging

Because of these risks, manufacturers use Good Manufacturing Practices (GMPs) to try to keep gluten levels below 20 parts per million (ppm), the FDA limit for gluten-free labeling. But even with these systems in place, the gluten-free status of commodity oats is still controversial.

Optically & Mechanically Sorted Oats

To reduce cross-contact, some companies sort oats after harvest using:

• Mechanical sorting (separates by size/weight)

• Optical sorting (separates by color/texture)

These processes help remove errant wheat, barley, or rye kernels. Manufacturers may test oats:

• After initial sorting

• After milling

• After final product manufacturing

If a batch tests over 20ppm, it cannot be sold as gluten-free. If it tests under 20ppm, it can be used for gluten-free products.

Testing frequency and methods vary by manufacturer, but all must be able to show, if audited by the FDA, that the final product meets the <20ppm requirement.

What Are Purity Protocol Oats?

Purity Protocol oats are grown and processed using strict, documented controls designed to minimize gluten exposure from seed to packaging.

While there is no legal definition, the most widely referenced standard is the Gluten Intolerance Group’s 2017 Purity Protocol framework, which outlines requirements for:

Growers

• Using pure, gluten-free seed

• Following strict crop rotations (3+ years without gluten grains)

• Maintaining isolation strips from neighboring wheat/barley/rye fields

• Undergoing third-party field inspections

• Using dedicated or properly cleaned equipment

• Storing oats only in gluten-free bins

• Providing traceability documentation

Processors & Manufacturers

• Dedicated gluten-free receiving, storage, cleaning, and milling systems

• Strict dust and air filtration processes

• Dedicated extrusion, filling, and packaging equipment

• Documented purging procedures when shared equipment is used

• Final product testing to ensure <20ppm gluten (or <10ppm for GFCO certification)

Why This Matters to the Gluten-Free Community

Purity Protocol oats undergo more controlled, transparent oversight than mechanically sorted oats. Many people with celiac disease find them safer and more reliable, though not everyone can tolerate oats.

If you choose to include oats in your diet:

• Look for Purity Protocol or GFCO-certified products.

• Be aware that even gluten-free oats can cause symptoms for some individuals.

Source: Allred, L.K., Kupper, C., Iverson, G., Perry, T.B., Smith, S. and Stephen, R. (2017), Definition of the “Purity Protocol” for Producing Gluten-Free Oats. CCHEM, 94: 377-379. https://doi.org/10.1094/CCHEM-01-17-0017-VO