Celiac disease. Odds are you know someone who suffers from it, but the odds are even higher that they don't even know it. An autoimmune disorder that is characterized by damage to the absorptive surface of the small intestine, celiac symptoms are triggered by exposure to gluten, a protein found in wheat, barley and rye. Abdominal pain, constipation, diarrhea, gas, bloating and extreme fatigue are all symptoms of exposure to gluten, while long-term consequences can range from anemia and bone loss to thyroid dysfunction and even cancer. With an occurrence rate of just over one in 100, it's estimated that only 5-10% of sufferers have actually been diagnosed.

Regardless of prevalence, treatment for celiac disease is always the same: a gluten-free diet for life. Sounds simple enough, but those who live by this strict standard quickly realize that gluten lurks in a number of foods, and even trace amounts of gluten can cause a reaction.

WHEAT-FREE AND GLUTEN-FREE ARE NOT THE SAME THING

Since gluten is found in wheat, barley and rye, following a gluten-free diet means avoiding any food that contains one or more of these grains as an ingredient. That means no wheat-based breads, pastas, pitas, crackers and cereals, no barley-based soups or beers, and no rye bread. It also means no wheat bran, couscous, kamut, matzoh, triticale, and spelt -- even though some (like spelt) are marketed as wheat-free, they all contain gluten, and therefore must be avoided completely.

More challenging is avoiding gluten-derived ingredients that lurk as seemingly innocuous ingredients or additives in a huge range of foods. For example, malt extract, malt vinegar and malt syrup are all barley derivatives, and therefore are verboten. Soy and teriyaki sauces are also no-no's for celiac sufferers.

GLUTEN-FREE EATING: WHAT'S ALLOWED

The list of foods that contain gluten seems daunting, but there are far more foods that are gluten-free, including all unprocessed fruits and vegetables, milk, cheese, beans, meats and fish, eggs, nuts and seeds. Rice, corn, potatoes and sweet potatoes are also safe, as are a number of ancient grains and seeds, like quinoa, buckwheat, millet, flaxseed, hemp and chia. And while glutenfree breads, cereals and baked goods used to be nutritional weaklings that tasted remarkably like cardboard, the quality, variety and availability of gluten-free products has improved enormously in recent years.

Historically, oats were not permitted in a gluten-free diet, but based on more updated research, the Canadian Celiac Association now endorses the inclusion of up to 50-75 grams (or about ½ to ¾ cup) of pure, uncontaminated oats per day (or 25 grams for children). The key, however, is that farming and manufacturing processes must be strictly controlled to prevent cross-contamination with wheat; unfortunately, few companies can boast this level of control (Lara's Oats from Creamhill Estates and Only Oats by Avena -- formerly Farm Pure -- are two of the only known producers of pure, uncontaminated oats in Canada).

GLUTEN-FREE EATING: WHAT'S MISSING

While a wide variety of foods are permitted in a gluten-free diet, the reality is that it is gluten-free diets tend to lack a variety of nutrients, including iron, calcium and dietary fibre, which occurs because of the common practice of replacing gluten-containing foods with unfortified white rice and other low-nutrient starches. Fortunately, several gluten-free companies are now enriching their foods with vitamins and minerals, and the rise in popularity of the ancient grains and seeds listed above has the potential to improve the quality of the gluten-free diet substantially.

A GLUTEN-FREE LIFESTYLE

But what about those who choose to follow a glutenfree diet for other reasons? Gluten-free diets are a common prescription from some health care practitioners, not to mention a growing number of celebrities and fitness experts to treat everything from fatigue to weight gain.

Not so fast, says Shelley Case, registered dietitian, celiac expert and author of Gluten-Free Diet. Because celiac disease is vastly undiagnosed, Case strongly encourages anyone who suspects they might have the disease to undergo the appropriate testing first. "One of the problems I'm seeing in my practice is that people have heard about gluten-free diets from celebrities, have started it, and now they aren't sure if they want to follow this diet forever," Case says. "The biggest harm [with experimenting with a gluten-free diet] is that if you really do have celiac but don't know it, you will not follow it to the red letter. You will have the occasional piece of pizza, or drink the occasional beer. Then you run the risk of complications, including osteoporosis, other immune disorders and possibly lymphoma. Plus your kids and family won't get screened." As a result of all of these challenges, Case argues that it's critical to get good advice from a dietitian specializing in celiac disease when starting any gluten-free diet.

- Jennifer Sygo is a dietitian in private practice at Cleveland Clinic Canada (clevelandclinic.ca),which offers executive physicals, prevention and wellness counselling and personal health care management in Toronto.

jsygo@rogers.com