Celiac Disease and Diabetes

Gluten is a protein found primarily in wheat. It is what gives bread its chewy texture.

Celiac disease at a glance

Like type 1 diabetes, celiac disease is an autoimmune disease. In people with this disease, eating gluten triggers an abnormal reaction by the immune system, damaging the walls of the small intestine. This damage interferes with the absorption of such nutrients as iron, calcium, and some vitamins.

Over the long term, nutritional deficiencies caused by the disease can lead to anemia (a deficiency in iron, folic acid or vitamin B12), osteoporosis (brittle bones due to a lack of calcium and vitamin D), fertility problems, and an increased risk of certain cancers.

Although we do not yet understand all the mechanisms, recent research clearly demonstrates that people with type 1 diabetes are at greater risk of developing celiac disease.

Symptoms

Sufferers can experience a wide range of symptoms. The most common are:

  • cramps, bloating, flatulence
  • constipation
  • chronic diarrhea
  • weakness/extreme fatigue
  • indigestion
  • weight loss
  • delayed growth and puberty (in children)
  • anemia
  • unexplained frequent hypoglycemia

In some cases, celiac disease is silent; that is, there are no symptoms. In other cases, sufferers develop dermatitis herpetiformis, an intense burning and itching rash characterized by blisters on the elbows, knees, buttocks and upper back.

Causes

Genetic factors have been associated with celiac disease. What’s more, the likelihood of developing the disease climbs to 10% if an immediate family member (parent, sibling) has the disease. People suffering from another autoimmune disease (type 1 diabetes, thyroid disease) or Down syndrome are also more at risk.

However, genes do not account for everything. The mechanisms that trigger the onset of symptoms are still poorly understood. In some cases, stress seems to play an important role. Indeed, the first symptoms often appear after a major physical or psychological stress, such as infection, surgery, pregnancy or emotional crisis.

Diagnosis

Celiac disease can occur at any age but is most commonly diagnosed between 30 and 60 years of age. Screening for the disease starts with a blood test to analyze the levels of disease-specific antibodies. If this test is positive, then a biopsy (tissue sample) of the small intestine is done. A biopsy that shows lesions confirms a diagnosis of celiac disease.

You should not start a gluten-free diet before having the biopsy, as this may falsify the diagnosis. In its 2018 guidelines, Diabetes Canada recommends screening people with type 1 diabetes who are experiencing symptoms related to celiac disease.

Treatment

Celiac disease is permanent, meaning it that it does not disappear over time. However, strict adherence to a gluten-free diet for life will eliminate the symptoms and help repair the intestine. Before starting such a diet, it is essential that a person with diabetes receive confirmation of the diagnosis by a physician, and get counselling from a dietitian specializing in celiac disease and diabetes. The dietitian will first ensure that the diabetes is properly controlled before starting a gluten-free diet.

Gluten-free diet and diabetes

Combing a gluten-free diet with diabetes can be a dietary challenge! If the diet is not balanced, it can lead to nutritional deficiencies and a rise in glycemia.

The difficulty arises from the fact that gluten is found in many common foods that people eat every day. In fact, this protein is found in wheat and related grains (including kamut, spelt and triticale), oats*, barley and rye. Consequently, all products made from these grains (e.g.: bread, pastries, breakfast cereals, cereal bars, cookies, crackers, pasta, couscous, bulgur, etc.) contain gluten.

By removing all these products from your diet, especially those made from whole wheat, you eliminate the main sources of dietary fibre, which help control blood glucose (sugar) levels. Moreover, alternative gluten-free products are often low in fibre, higher in carbohydrates and provide less protein.

Here are a few tips that can help diabetics with celiac disease make healthy gluten-free choices:

  • Eat foods that are as minimally processed as possible (vegetables, fruits, fish, poultry, eggs, nuts, milk, etc.)
  • Avoid fried or breaded foods (restaurant cooking oils are often contaminated with gluten, and breadcrumbs typically contain gluten)
  • Replace wheat products with naturally gluten-free starches (potatoes, rice, corn, quinoa, corn tortillas, rice cakes, rice vermicelli)
  • Choose whole grains (brown rice, quinoa, amaranth and buckwheat) and legumes (chickpeas, beans, lentils, soybeans, etc.) to optimize your intake of fibre and protein
  • Use your own toaster oven and your own jars of jams and spreads (mayonnaise, mustard, etc.) to avoid cross-contamination
  • Avoid hidden sources of gluten, such as oats *, soy sauce, seafood substitutes (pollock), grain-based alcohol (beer), certain soups and soup stocks, sausages and cold cuts.

Note that the above list is not exhaustive and should not replace personal advice from a dietitian specializing in celiac disease and diabetes.

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*According to Health Canada, a small amount of pure oats, uncontaminated by other grains, should not be a problem for most people suffering from celiac disease.

For more information:
Canadian Celiac Association
Fondation québécoise de la maladie cœliaque (French only)

To find a dietitian:

Ordre professionnel des diététistes du Québec

Research and text: Diabetes Québec Dietitian Team

Text adapted from: Bergeron, C., dietitian, (Winter 2013-2014),”Intolérance au gluten et diabète : y a-t-il un lien?, Votre diététiste vous répond,” Plein Soleil, Diabetes Québec, pp. 20-22.

Other source: Wherrett D, Ho J, Huot C et al. Diabetes Canada 2018 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada: Type 1 Diabetes in Children and Adolescents. Can J Diabetes 2018; 42 (Suppl 1): S234-S246.

Last update: July 2018

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