A new study led by CSIRO researchers has identified a common weed that may be contaminating gluten-free crops with gluten-like allergens.
A common weed, called ryegrass, contains gluten-like proteins that could potentially cause adverse reactions in people with coeliac disease or gluten intolerance.
The study, led by Dr Sophia Escobar-Correas, from Edith Cowan University (ECU) and Australia’s national science agency (CSIRO), has identified 19 proteins in ryegrass that have similar properties to gluten proteins.
The weed is commonly found in fields growing gluten-free crops, such as millet, buckwheat and sorghum, and researchers think it could be sneaking into the processing of these crops, all the way to the final product.
The goal behind this project was to find out why a small percentage of people with gluten sensitivity still get sick after consuming gluten-free products. “We asked ourselves why these patients are still getting sick. And we realized that there are other grains that grow in the field (alongside gluten free crops), and this can end up in the food chain,” Dr Escobar Correas told Medical Forum.
About the study
According to the Department of Primary Industries and Regional Development, ryegrass is “one of the most serious and costly weeds of annual winter cropping systems in southern Australia.” The weed is highly competitive, produces a high number of seeds, up to 45,000 per square metre and some populations have now developed herbicide resistance.
With this information at hand, Dr Escobar Correas and her team decided to look into ryegrass and whether it hosted proteins similar to gluten. Researchers studied 10 cultivars of ryegrass commonly found alongside Australian cereal crops and analysed their protein content.
“We have developed a method to detect these ryegrass proteins that allows us to distinguish them from other grains,” Dr Escobar Correas said. The development of this test was an important development, as until similar tests were only available to test crops like rye or barley.
The new method, which employs mass spectrometry, identified 19 different proteins that had properties similar to gluten proteins.
“While these proteins aren’t strictly defined as gluten, they have the potential to trigger reactions for people who are coeliac and those with a gluten intolerance,” Dr Escobar Correas added.
With this information in the table, researchers will now ask if any of these proteins are currently found in gluten free products. However, new tests will need to be developed to identify these new proteins. “Personally, I think there is some possibility, you know, like we can find these in food. But I think that’s why it’s important to have the right practices to test it,” Dr Escobar Correas told Medical Forum.
“If these proteins cause a reaction for people with gluten intolerance, then it’s important that we develop tests to detect their presence in food products which are otherwise gluten-free,” she said.