October 2013 Issue

Preventing Cross-Contamination — Expert Tips to Help Clients Adhere to a Gluten-Free Diet at Home
By Marlisa Brown, MS, RD, CDE, CDN
Today’s Dietitian
Vol. 15 No. 10 P. 16

Carl, 15, who lives with his parents and two siblings, recently was diagnosed with celiac disease. Though he claims to be 100% compliant in following a gluten-free diet, he continues to experience distressing gastrointestinal (GI) symptoms at least three to four times per week. When his dietitian asked him how food was prepared at home, she discovered that Carl was toasting his gluten-free bread in the same toaster his family members used to toast their gluten-containing bread. Carl told her that he always cleans the toaster before using it, but this precaution isn’t enough to avoid GI symptoms.

According to Suzanne Simpson, RD, a clinical dietitian at the Celiac Disease Center at Columbia University in New York City, the toaster often is a source of cross-contamination. A common misconception is that a freshly cleaned toaster is safe to use, but it’s not, she says. Even a crumb of bread containing gluten is enough to cause illness in someone with celiac disease.

But while the toaster can be a chief cause of cross-contamination, it’s not the only source. Cross-contamination can occur when family members prepare gluten-free and gluten-containing foods on the same cooking surfaces and prep areas and use the same common kitchen items such as colanders, dish towels, utensils, and baking sheets. This can be problematic for individuals with celiac disease, gluten sensitivity, or wheat allergy, who must avoid gluten completely to prevent adverse reactions.1

Celiac Plain and Simple
Celiac disease is an autoimmune disorder characterized by a permanent intolerance to the protein gluten, which is found in wheat, rye, barley, and other grains. It affects 1% of the population, or approximately 3 million people in North America alone.2

When people with celiac disease consume gluten, their immune system responds by damaging the small intestine. If celiac disease is left untreated, it can cause GI and non-GI symptoms such as diarrhea, bloating, gas, constipation, fatigue, headache, joint pain, nutritional imbalances, and diseases such as Hashimoto’s thyroiditis, autoimmune hepatitis, type 1 diabetes and, in rare cases, intestinal cancer.

People with gluten sensitivity can’t tolerate gluten but don’t have celiac disease. It’s estimated to affect approximately 5% to 6% of the population, or about 15 to 18 million people.1,3 In recent years, gluten sensitivity has been recognized as a disease, with the diagnostic protocol established in June 2011.4

When gluten-sensitive individuals eat gluten-containing foods, generally they experience GI symptoms but not the intestinal damage associated with celiac disease. Whether or not gluten sensitivity leads to autoimmune conditions hasn’t been established, so physicians and researchers currently focus on the GI symptoms.5

Home Safety
When counseling clients and patients about celiac disease and gluten sensitivity, it’s important to educate them about avoiding the possibility of cross-contamination in the home, especially if they live with family members who don’t have these conditions.

Today’s Dietitian spoke with three celiac disease experts who have provided the following strategies you can share with clients to help them prevent cross-contamination and therefore the symptoms associated with gluten ingestion.

Simpson makes the following recommendations:

• Don’t use wooden spoons or cutting boards that also are used to prepare gluten-containing foods because the spoons and boards can harbor residual gluten and bacteria. Metal or plastic are better options.

• Cover shared grilling surfaces when barbequing because unless the grill reaches 500˚F or higher for 30 minutes or longer, grilling won’t eliminate any residual gluten.

• Buy a separate waffle maker or bread maker if the one the family uses doesn’t have parts that can be disassembled and placed in the dishwasher.

• If using a separate toaster isn’t possible, use toaster-safe toaster bags such as Celinal Toast-It or Vat19 ToastIt, available online.

Pam Cureton, RD, LDN, a dietitian at the Center for Celiac Research at the University of Maryland, adds these tips:

• When planning parties at home, prepare a buffet of foods that are 100% gluten free to prevent accidental cross-contamination among family members and guests.

• Buy squeezable condiment containers for ketchup, mustard, and mayonnaise to prevent double dipping. If you don’t purchase squeezable containers, mark condiment jars as safe depending on whether they’ve been exposed to gluten-containing foods.

• Store gluten-free products on the top shelf of the pantry or refrigerator so other foods don’t accidentally cross-contaminate them.

Shelley Case, BSc, RD, president of Case Nutrition Consulting and author of Gluten-Free Diet: A Comprehensive Resource Guide, offers the following ideas:

• In supermarkets, don’t buy unpackaged foods stored in bins. The scoops used to place the foods in bags or containers may have been previously used on nearby gluten-containing foods and may not have been sufficiently cleaned.

• Use different colored stickers to distinguish between gluten-containing and gluten-free products in the pantry and fridge.

• Purchase a colander in a different color for gluten-free foods so it doesn’t get mixed up with the colander used for gluten-containing foods.

• Buy gluten-free grains that are certified gluten free to ensure cross-contamination didn’t take place during processing.

• Buy gluten-free flours marked as gluten free from reputable companies that are more likely to test for gluten.

• Avoid purchasing imported foods. Other countries may not abide by the same gluten-free standards as the United States.

Difficult Family Members
Of course, even if clients follow these tips to the letter, they still may be exposed to gluten because of uncooperative family members.

Many families support those who must follow a gluten-free diet, but others do not. Siblings may be uninformed about celiac disease and gluten sensitivity and not realize the seriousness of the conditions. Others may not believe the person really has celiac disease and may think that the person just wants attention or that the cross-contamination issues are overkill and unwarranted.

To educate family members, suggest clients share written information about celiac disease and gluten sensitivity and also show family members scientific evidence that supports the risks of cross-contamination. If they’re still unconvinced, recommend family members attend a nutrition counseling session to get information about the disease firsthand.

When all else fails, recommend patients acknowledge family members’ frustration but mention that if they don’t follow a gluten-free diet 100% of the time, it can cause intestinal cancer. Resistant family members who hear this startling possibility may change their attitude.

Overall, when working with a patient who needs to follow a gluten-free diet, it’s important to remember that the more tools you give them, the easier it will be for them to adhere to the diet and prevent cross-contamination.

— Marlisa Brown, MD, RD, CDE, CDN, is president of Total Wellness, a private nutrition consulting company specializing in diabetes, cardiovascular disease, gastrointestinal disorders, gluten-free diets, culinary programs, corporate wellness, and medical nutrition therapies, and author of Gluten-Free Hassle-Free and Easy Gluten-Free.


1. Sapone A, Bai JC, Ciacci C, et al. Spectrum of gluten-related disorders: consensus on new nomenclature and classification. BMC Med. 2012;1110:13.

2. Rubio-Tapia A, Ludvigsson JF, Brantner TL, Murray JA, Everhart JE. The prevalence of celiac disease in the United States. Am J Gastroenterol. 2012;107(10):1538-1544.

3. Sanders DS, Aziz I. Non-celiac wheat sensitivity: separating the wheat from the chat! Am J Gastroenterol. 2012;107(12):1908-1912.

4. Ludvigsson JF, Leffler DA, Bai JC, et al. The Oslo definitions for coeliac disease and related terms. Gut. 2013;62(1):43-52.

5. Biesiekierski JR, Newnham ED, Irving PM, et al. Gluten causes gastrointestinal symptoms in subjects without celiac disease: a double-blind randomized placebo-controlled trial. Am J Gastroenterol. 2011;106(3):508-514.