Cross-Contamination, Cross-Contact, and Gluten-Transfer

Have you heard of “cross-contamination”? It is a term often used to refer to gluten-free food coming into contact with gluten. For example, oats are naturally gluten-free but may contain gluten if they have been cross-contaminated, or touched by, gluten, either in processing or packaging. Experts recommend we now use the term “cross-contact” instead, because cross-contamination is also used in the world of food safety and food service; it refers to food being exposed to bacteria or other microorganisms that could result in illness when eaten. If we use that definition, it makes it sound like we can cook / kill the contaminant, right? So let’s not confuse things. We cannot get rid of gluten with cooking, so I will try to only use the term “cross-contact”.
 
If you have celiac disease, any exposure to gluten can make you sick, causing an autoimmune response even if you do not feel it. It is critical that you avoid all gluten, all the time. Beyond Celiac has designed an infographic to help you think about potential gluten sources not just in food but in toys, lotions, and kitchen equipment: Hot Spots
 
If you have a gluten-related disorder, such as non-celiac gluten sensitivity, you may experience the same symptoms as someone with celiac or you may have fewer or more symptoms of varying degrees of severity. It is very individual. That said, the jury is still out about the degree of cross-contact to cause you concern. For many of us who do not have celiac disease, we are able to tolerate small amounts of cross-contact without harm. The rest of this blog is for gluten-related disorders, not celiac disease.
 
When you are first diagnosed, it is important to follow an elimination diet and reintroduction of foods to determine your sensitivities, as you know from reading my previous blogs. In this blog, we will consider cross-contact in food processing and packaging, stores and markets, restaurants, and at home.
 
FOOD PROCESSING AND PACKAGING
Continue to read ingredient lists on food packages and continue to avoid wheat, barley, rye and anything derived from them! Remember, too, that refining and processing equipment may be shared with wheat and other gluten-containing foods. The FDA gluten-free labeling rule is voluntary so it is our responsibility to read ingredients and call the manufacturer if we are not sure.
 
GROCERY STORES AND MARKETS
As discussed in previous articles, bulk bins and deli items are potential sources of cross-contact and you should proceed with caution. You could do your research and ask a lot of questions, but I just avoid both for now. 
 
RESTAURANTS
When eating out, I check the restaurant’s website to view the menu ahead of time. If it isn’t available, or you forget, take your time in reviewing your choices and ask the server to check with the chef if you want to make sure gluten-free items are kept separate from gluten-containing items. I avoid buffets, as utensils, fingers or other food may accidentally come in contact with foods that are naturally gluten-free. Be careful with fried foods, too; many restaurants (including fast food) use the same fryers to cook French fries and breaded chicken, so you would likely get gluten with your potatoes. This reference may help you decide what to choose at fast food establishments: GF Fast Food.
 
AT HOME
Unless you keep a completely gluten-free household, you may come into contact with gluten in your home. Common causes of concern include the toaster, toaster oven, convection oven, utensils, pots and pans, griddle, cutting board, and even dishcloths and sponges.

In your toaster and toaster oven where food comes in direct contact with cooking surfaces, and in convection ovens, where a fan blows food particles including gluten that may have been in the oven previously, your gluten-free foods may receive gluten transfer. Traditional advice recommends sharing toaster ovens and convection ovens only if your food is covered; I do not worry about this will discuss further in a minute.
 
Significant gluten transfer can also occur with utensils, dishes and cookware. Do not use the same knife, for example, to cut or butter GF and wheat bread, and do not use the same serving spoon to scoop up GF foods and those with gluten. Do not share a knife between condiments, either; peanut butter, mayonnaise and other spreads need their own utensils - and double dipping needs to be avoided. Same with sharing dishes and cutting boards - don't. As for cookware, foods cooked in a fryer that also cooks gluten-containing foods can cause enough gluten transfer to be a problem, as can griddles that cook pancakes and waffles. Be sure to wash all dishware and cookware between uses.
 
Lastly, you may need separate dishcloths and sponges to clean gluten-free dishes and cookware, and always use fresh water to rinse. This category of cleaning items is eliminated if you use the dishwasher, and actually not a problem for most people with gluten-disorders who do not have celiac. While I am careful not to share utensils and cutting boards with gluten and GF foods, I have never had an issue with dishcloths or sponges.
 
For more information, enjoy this guide to reducing cross-contact here.
 
So, does all cross-contact matter? For me personally, and for many of my friends and clients, the small amount of gluten in a toaster or convection oven does not cause us any discomfort. Nuts processed in a facility that processed wheat, however, caused problems. With a careful food diary, we were able to track symptoms to their sources. (Remember, if you have celiac, you must follow the strictest guidelines).  New research published in the journal Gastroenterology in January 2020 supports this; it showed that gluten exposure in the kitchen varies. For example, they found gluten transfer in toasters to be low and that typical dishwashing removes gluten so that separate pots are not needed. You can read more here and here.
 
While you learn more about cross-contact and get in tune with your body, stay well, my friends, and remember to eat mindfully and joyfully.