Healthy Living

Why is cross contamination such a big deal for celiac disease?

Even a little gluten is a big deal when you have celiac disease. Understanding what gluten cross contamination is and how to prevent it is critical when managing this condition.

Celiac disease triggers an autoimmune attack in response to the consumption of gluten.

Gluten is a protein found in wheat, barley, and rye. It acts like a binder and is what gives elasticity to foods made with these grains, such as pizza dough or pancakes.

Are oats gluten free?

Numerous foods and beverages contain gluten. It may also be found in many everyday products. Possible risks include medications, vitamins, lotions, shampoos, hand soaps, lipstick, makeup, pet food, etc.

Reading labels is very important when you have celiac disease.

Additionally, gluten free foods may become cross contaminated when precautions are not taken. Fortunately, this can be prevented using simple cleaning and planning practices.

How much gluten matters?

It takes very little gluten to trigger the autoimmune response in people with celiac disease. The scientific threshold is 20 parts per million (ppm) or higher.

Autoimmune means the immune system attacks healthy cells when that abnormal response is triggered. For celiac disease, the trigger is gluten.

When a person with celiac disease eats a food with 20 ppm or higher of gluten in it, their body will have an autoimmune response and suffer damage.

To put that in perspective, 20 ppm of gluten is less than a single crumb of wheat bread.

This is where cross contamination becomes really important when managing celiac disease.

For example, let’s say you are making gluten free toast. If you place your gluten free toast on a plate that has wheat toast on it (or even some leftover crumbs from that wheat toast), your gluten free toast will become cross contaminated. A single wheat crumb is more than enough to cause damage!

Since your toast is no longer truly gluten free, it is not safe for someone with celiac disease to eat. Shared slot toasters are another no-no! #nocrumbsplease

Cross contamination can happen in your home, at school, work, restaurants, or social events. Education and preparation are key.

Now, we can’t talk about cross contamination without a quick anatomy lesson. But don’t worry. I’ll keep it quick and simple.

Meet your amazing villi!

The inside walls of our small intestine are covered in tiny finger-like projections called villi. These villi have a very important job. Their role is to catch the nutrients from the things we eat.

As the foods, beverages, and supplements we consume pass through our small intestine, our villi collect their nutrients.

Simply put, the stomach digests (breaks down) nutrients; the villi absorb (collect) nutrients.

These nutrients are then transferred from our villi to our bloodstream. From here, our plasma (which is part of our blood) delivers these nutrients throughout our body.

This is what feeds every single part of our body.

Simply eating healthy food is not enough. We need our villi to ensure we get enough carbohydrates, proteins, fats, vitamins, and minerals to survive and thrive.

Our villi also aid in the collection and transfer of any oral medications we are taking to treat an illness or disease.

This process is more complicated as different drugs are designed to be absorbed by the body in different ways. Regardless, if the villi can’t do their job correctly, then our medication efficacy may be affected too.

When a celiac patient consumes gluten, their body attacks these villi. This causes damage to and shortening of the villi.

Continued exposure to gluten may result in the villi becoming completely flattened. Medically, this is called, “complete loss of villi.”

Even minor inflammation and damage to the villi, such as after cross contamination, impairs their ability to absorb nutrients.

A healthy small intestine is lined with finger-like projections (villi) which help the intestine to absorb nutrients. With celiac disease, the villi become damaged and flattened. This may affect the absorption of nutrients.
A healthy small intestine is lined with finger-like projections (villi) which help the intestine to absorb nutrients. With celiac disease, the villi become damaged and flattened. This may affect the absorption of nutrients. (Image Credit: About Kids Health)

Malnourishment affects every part of the body.

Damaged or flattened villi leads to the development of serious health conditions related to malnourishment and systemic inflammation.

Symptoms of malnourishment that may be from celiac disease:

  • Recurrent vitamin or mineral deficiencies, especially iron, vitamin D, calcium, magnesium, zinc, folate (vitamin B-9), vitamin B-12, and fatty acids (omega-3 and omega-6)
  • Osteopenia or osteoporosis
  • Weight loss (more common in young children)
  • Dental enamel defects (stains, pits, lines, and grooves)
  • Partial or complete loss of enamel
  • Delayed tooth eruption
  • Frequent cavities
  • Recurrent mouth ulcers (canker sores)
  • Failure to thrive or short stature 
  • Delayed onset of puberty
  • Amenorrhea (no period) or highly irregular menstrual cycle
  • Unexplained infertility, recurrent miscarriage, stillbirth 
  • Requiring higher than normal or ever-increasing medication dosage to treat an illness or disease

This far from a complete list of possible celiac disease symptoms. In fact, there are over 300 known signs and symptoms of celiac disease.

Celiac disease affects the whole body.

Crohn’s disease and other conditions can also affect the small intestine and lead to malabsorption of nutrients.

Talk to your doctor about getting tested for celiac disease and its related conditions if you are experiencing any of the symptoms.

How to Prevent Gluten Cross Contamination

Thoroughly clean all cooking utensils and any surfaces used to prepare gluten free food before beginning. The best way to clean them is with dish soap and water. Disinfectants do not remove gluten or other allergens.

Store your gluten free foods in sealed containers or bags to prevent crumbs.

If you don’t have a fully gluten free household, then make sure your GF foods are clearly labeled. This will reduce the risk that they get eaten or cross contaminated by someone else.

Layered Living offers educational classes and health coaching programs to support individuals and families transitioning to a gluten free diet.

Contact me to learn more.


Anderson, J. (2020, November 23). Why Untreated Celiac Disease Can Cause Malnutrition. Retrieved April 13, 2021, from

Bauer, K. (2020, June 22). Celiac disease and nutrient deficiencies: How are your zinc levels? Retrieved April 13, 2021, from

Beyond Celiac. (2021, February 08). Celiac disease: Fast facts. Retrieved April 12, 2021, from

Beyond Celiac. (2021, February 09). Symptoms of Celiac Disease. Retrieved April 13, 2021, from

Cailas, S. (2020, March 12). Malnutrition in People with Celiac Disease. Retrieved April 13, 2021, from

Celiac Disease Foundation. (n.d.). Celiac Disease and Gluten-Related Conditions. Retrieved April 12, 2021, from

Cloe, A. (2018, April 13). The Importance of Villi and the Small Intestine to Digestion of Nutrients. Retrieved April 13, 2021, from

Gluten: A Benefit or Harm to the Body? (2020, March 20). Retrieved April 13, 2021, from

Disclaimer: I am not a doctor. This blog post is general information only and is not to be substituted for medical advice, diagnosis, or treatment.

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