The optimal gluten-free diet

Lifelong adherence to a gluten-free diet is the only treatment for coeliac disease. Dietitian, LORI WELSTEAD from the University of Chicago Celiac Disease Centre shares with us her tips on how to follow a gluten-free diet, that’s good for you too.

Currently, the only treatment for coeliac disease is a life-long avoidance of gluten-containing foods. Strict adherence to the gluten-free diet often minimises bloating, diarrhoea, weight loss, fatigue and begins the healing process. I have known patients who have begun to feel improvements within days of eliminating gluten from their diet. However, complete intestinal healing may take up to a year depending on the degree of intestinal damage, as well as intermittent, unintended gluten ingestion.

The uppermost section of the small intestine is called the duodenum. Here small finger-like protrusions known as villi, increase the surface area to maximise vitamin absorption. The villi themselves have microvilli on their tips; it is their job to break down proteins and a variety of sugars, including lactose.

If an individual with coeliac disease consumes gluten, the immune system responds by damaging the small intestine and particularly the villi. At the time of diagnosis, the villi may be partially shortened or completely flattened. Without villi, the ability to properly digest and absorb nutrients diminishes considerably. Prior to diagnosis people with coeliac disease typically have malabsorption issues. This is why it is important your doctor checks for nutrient deficiencies at the time of your diagnosis.

Vitamins, Minerals and You

The most common nutrient deficiencies in patients with newly diagnosed coeliac disease are iron, vitamin B12, folate, calcium, vitamin D and zinc. The risk of nutrient deficiency is related to the degree of malabsorption, inflammation and intestinal damage at the time of your diagnosis.

The duodenum is the main site of iron absorption and it also happens to be the place where most damage to the villi occurs. Unsurprisingly, many newly diagnosed coeliac patients suffer from iron deficiency anaemia as a result of malabsorption.

It can take time for iron stores to normalise after diagnosis. In most adults, haemoglobin levels (the iron-containing protein found in red blood cells) will return to normal within a year and within two years iron stores should have stabilised. Eating foods rich in iron will help. Be sure to include beef, turkey, liver, egg yolks, sardines and oysters in your diet.

Vitamin B12
Vitamin B12 plays an important role in the production of red blood cells. In people newly diagnosed with coeliac disease, the rates of B12 deficiency vary. Studies have reported deficiencies in between 8 to 41 percent of patients. It correlates with extensive disease, as most absorption takes place in the ileum (the third portion of the small intestine).

A gluten-free diet, along with a multivitamin, is often sufficient for repletion of vitamin B12, although occasionally additional supplementation may be necessary. Dietary sources of vitamin B12 include shellfish, liver, dairy, beef and eggs. Due to their avoidance of all animal products, vegans are at risk of developing a vitamin B12 deficiency.

Studies have shown that 35–49 percent of newly diagnosed coeliac patients have a folate deficiency. Your GP should check your folate levels at the time of diagnosis and during annual follow-up visits. Unlike their gluten-containing counterparts, gluten-free foods are not fortified with folate. Women of childbearing age must be especially mindful of adequate folate levels and intake due to the importance of folate to the development of the foetus.

Vitamin D and Calcium
The connection between bone health and coeliac disease has been the basis of numerous studies. A review by Italian researchers suggests 75 percent of untreated adult patients with coeliac disease suffer from a loss of bone mass. Bone mineral density is related to inflammation from active disease as well as poor absorption.

Calcium and vitamin D are both absorbed in the duodenum, explaining why malabsorption is such an issue for those with undiagnosed coeliac disease. Strict adherence to a gluten-free diet will enable the damaged villi to heal. Once healed, the body begins to absorb essential vitamins and minerals like calcium and vitamin D. Adult patients with coeliac disease should have a calcium intake of at least 1000 mg per day. Dairy products, including milk, cheese, yoghurt are the best natural sources of calcium. Non-dairy sources include broccoli, sardines and canned salmon. Supplementation options exist when necessary.

While the villi are damaged, people with coeliac disease may experience lactose intolerance as the tips of the villi are home to lactase enzymes. For readers who experience gas and bloating from lactose, the good news, is that as your intestine heals these GI-symptoms should diminish.

I recommend my patients who suffer from gas, bloating and diarrhoea at diagnosis avoid lactose initially to reduce these symptoms. Then after several weeks to months following a strict gluten-free diet, lactose containing products can be reintroduced without overt symptoms of intolerance.

Bone mineral density is related to inflammation from active disease as well as poor absorption. Calcium and vitamin D are both absorbed in the duodenum, explaining why malabsorption is such an issue for those with undiagnosed coeliac disease.

The Gluten-Free Diet

The gluten-free diet can be balanced and healthy with the inclusion of foods that are naturally gluten-free before processing. However, it is easy to be drawn to the convenience of processed gluten-free foods that are high in fat, sugar and sodium without vitamin and mineral enrichment or fortification. Just because a product is labelled gluten-free, it does not mean it is healthy or better for you.

Instead, look for foods that are nutrient-dense. These are naturally good sources of vitamins and minerals and provide a balanced and adequate intake. These include fruits, vegetables, beans, nuts, seeds, fish, lean meat, poultry and dairy.

The first step in managing the gluten-free diet is to understand which foods contain wheat, rye, barley and oats so you can eliminate them from your diet, to allow intestinal healing to begin. “If in doubt, leave it out,” is what I tell my patients. Fresh foods, without any processing or additives, including fruit, vegetables, dairy products, fish and meat are all naturally gluten-free.

Gluten is versatile, as it provides a variety of functions in foods. Removing gluten results in a denser finished product. Sugar and fat are often added to provide a similar mouthfeel, which can result in higher calories. A recent study in Spain analysed the nutritional content of gluten-free and gluten-containing products and it revealed significant differences. Gluten-free products contained more fat (predominantly saturated fat), more sodium and less fibre and protein than their gluten-containing counterparts.

The good news is that many manufacturers have started to introduce bean and nut flours into their gluten-free products. Not only has this improved the texture of the products, but it has also increased their nutritive value and may aid in reducing the effect of weight gain on a gluten-free diet.


Cross-contamination is said to occur when gluten-free food comes into contact with food containing gluten. Unfortunately, gluten exposure from cross-contamination may lead to ongoing disease activity. Due to a higher risk of cross-contamination, it is recommended to avoid grains and flours from bulk bins and only to purchase flours and grains labelled gluten-free. While in shared kitchens condiment containers that allow the use of spoons or other utensils may be at risk of cross-contamination along with cutting boards, toasters and colanders.

A gluten-free diet has become easier to follow with the explosion of gluten-free products and increasing options available when eating out. However, when dining outside of your own home, you must remain cautious. While the venue may have the very best intentions, cross-contamination risks are high. Despite offering a gluten-free menu, many restaurants do not follow strict guidelines to avoid cross-contamination. Communication between the wait staff and the kitchen is crucial to the safe preparation of your gluten-free meal.

Fortunately, chefs have become more aware of the gluten-free diet and concerns regarding cross-contamination over the past decade. In 2003, researchers interviewed chefs in the UK city of Sheffield to gauge their awareness of gluten-related disorders. In 2013, the researchers went back to Sheffield and posed the same questions to chefs in the area. In the follow-up study 10-years later the researchers found a significant increase in the chef’s awareness. Recognition of coeliac disease went from 17.1 percent in 2003 to 78.1 percent in 2013, while awareness of gluten sensitivity grew from just 9.3 percent in 2003 to 87.5 percent ten-years-later.

The Role of the Dietitian
With so much misinformation online, it is not uncommon to experience feelings of anxiety or confusion when trying to navigate the gluten-free diet. An accredited practising dietitian (APD) can help you adhere to the diet, particularly in the early stages after diagnosis. By closely reviewing your diet and lifestyle an APD can identify any potential sources of gluten exposure. The areas they will focus on include possible cross-contamination in your home, the frequency and locations of places you dine out and products purchased that may be cross-contaminated. An APD can also help direct you to reputable sources of information to empower you to live each gluten-free day with confidence.

This article first appear in Australian Gluten-Free Life magazine Issue 7 as The Optimal Gluten-Free Diet.

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