The one food I get asked about the most, surprisingly, is oats. It seems like anytime I discuss nutrition with a patient, the first question is “Okay, but what about oats?”. So many people seemingly have a love affair with oats, which also have a reputation for being healthy in conventional nutrition, but is that reputation deserved?
Oats are a good source of fiber and contain magnesium, iron, phosphorus, zinc, folate, copper and vitamins B1 and B5. There is also evidence the beta-glucan in oats improves insulin and blood sugar levels, as well as cholesterol (if you believe that matters) and promotes healthy gut bacteria. Oats also makes people feel full, which aids in weight loss, and they can help relieve constipation in some people.
The majority of the health benefits of oats derive from them being a good source of soluble fiber, thus improving gut health, which is central to all of health. Many people do not get enough fiber and do not have tremendous gut health, making oats a quick fix. There are a few things to consider, however, before making oats your daily source of fiber.
While oats do not genetically contain gluten, they are a common cross-reactive food that the body sometimes responds to as if it were gluten. This is due to a similar molecular amino acid structure between gluten and oats. There is a protein in oats called avenin that is similar in function to a protein in gluten called gliadin. Because of this similarity, the avenin in oats is capable of activating gluten-reactive T cells independent of ever consuming actual gluten.
So, if a person has developed antibodies to gluten, their body may also identify oats as gluten and initiate the same inflammatory immune response as though gluten has been consumed. In this presentation, eating oats would immunologically be the same as eating gluten.
Cross-contamination with gluten is common during harvesting, milling, transportation and processing. Oats are often grown alongside fields of crops containing gluten, such as wheat. The same field equipment is also commonly used to harvest both gluten-containing wheat and gluten-free oats.
Once they reach the processing facility, more cross-contamination with other gluten-containing grains––such as wheat, barley and rye––is possible during storage, preparation and packaging.
A 2008 study found oats to be the most problematic in terms of gluten cross-contamination, stating, “For regular cereal foods, the most critical issues were the contamination of oats- and buckwheat-based foods with wheat or barley.”
Another 2008 study examined 134 commercial oat products from Europe, the United States and Canada. Testing found gluten contamination in 109 samples (81%), leading study authors to conclude that “most oats are contaminated with mixtures of wheat, barley and rye.”
A Canadian study in 2011 found the commercial oat supply to be “heavily contaminated with gluten from other grains”, concluding approximately 88% of the oat samples had been contaminated with gluten.
Conventional oats––along with wheat––are one of the crops most heavily sprayed with a cancer-causing herbicide called glyphosate, also known as RoundUp. Organic oats are indirectly contaminated with glyphosate when the toxic chemical––which is banned or restricted in many countries––blows over from nearby fields during spraying or during processing.
In 2018, Environmental Working Group (EWG) conducted testing on conventional and organic oats to test for the presence of glyphosate. EWG found 43 out of 45 conventional oats and 5 out of 16 organic oats tested positive for the carcinogenic chemical.
Two months later, EWG ran another round of testing and found glyphosate in 100%––28 out of 28––of popular oat-based cereals and other oat-based foods marketed to children. Products included granolas, instant oats, overnight oats, oat breakfast cereals and snack bars.
While oats are extremely popular, the potential downsides outweigh the upsides. My outlook on nutrition is derived from an ancestral, paleo perspective. As such, no grains are included in this approach, and as oats are a grain, they are to be left out.
In addition, the potential for cross-reactivity in the body by the immune system––which can lead to chronic, systemic inflammation––is reason enough to remove oats from the diet. If this is a concern, running a food immunology Array 4 test through Cyrex Labs can identify out of range markers for oats, in addition to evaluating around 30 other similar gluten cross-reactive foods.
Lastly, independent testing has shown oats are very commonly contaminated with both carcinogenic glyphosate and inflammatory gluten. Although oats do contain fiber, vitamins, minerals and antioxidants, so do a vast majority of other healthy foods. Oats are not a nutrient-dense food, nor are they nutritionally unique in any way. We can get everything oats contain from other foods––minus the potential hazards.