A fire-roasted veggie sandwich produced with gluten-rich wheat. Image: wEnDy/Flickr/CC BY-NC-ND 2.0
In recent decades, fat, sodium, carbohydrates, sugar and protein have all been targeted as ‘bad’ dietary factors. Right now the focus seems to have shifted to gluten: a protein found in cereal grains, especially wheat but also rye and barley. For a small proportion of consumers, such as those diagnosed with coeliac disease or wheat allergy, the avoidance of wheat and other gluten-containing foods is essential. Symptoms for sufferers can include nausea, vomiting, cramping, bloating, abdominal pain, fatigue and even very serious conditions such as liver disease.
The prevalence in the population of coeliac disease and wheat allergy, while significant, sits between 1-2%.
But the growing number of consumer foods labelled as either gluten or lactose free, and the popularity of restrictive diets like the paleo diet, would suggest more people are making the choice to go gluten or wheat-free – above what the coeliac and wheat allergy statistics would suggest.
To understand more about this trend, we conducted a nationwide survey of nearly 1200 people selected at random from the Australian electoral roll. The aim of the research was not only to quantify the prevalence of wheat avoidance in Australia but also to pioneer understanding of the drivers underpinning this decision.
Wheat avoidance in Australia
The data collected revealed that as many as 1 in 10 Australian adults, or approximately 1.8 million people, were currently avoiding or limiting their consumption of wheat-based products. Women were more likely to be avoiding wheat than men.
The survey also revealed that over half (53%) of those who were avoiding wheat were also avoiding dairy-based foods.
Why is this an issue? According to current Australian Dietary Guidelines, both grain and dairy-based foods are an important component of a balanced diet. They contribute significantly to the daily dietary fibre and calcium intake of both adults and children. They also deliver other important nutrients such as protein, vitamins and minerals, and – if eating whole grain – resistant starch.
So why are people choosing to avoid wheat?
The reasons behind this decision are complex. Some respondents reported that they were avoiding wheat due to a diagnosis of coeliac disease (1.1%), or because a family member has been diagnosed with coeliac disease. Others stated they were avoiding wheat for weight-control or taste preferences.
However, the vast majority of the survey’s wheat-avoiding respondents – which equates to 7% of (non-coeliac) Australians – were avoiding wheat-containing foods to manage a range of adverse symptoms they attributed to the consumption of these products. Symptoms were mostly gastrointestinal in nature (bloating, wind and abdominal cramps) but also included fatigue/tiredness.
When asked if they had any formal diagnosis including that of an intolerance, allergy, or coeliac disease which required them to avoid wheat, most (84%) of these symptomatic individuals said no.
So what sources are people relying on when it comes to making decisions such as avoiding wheat? There is a great deal of information which links the consumption of specific foods to adverse symptoms. According to our data, those who decide to eliminate wheat tend to do so based on advice from sources such as complementary practitioners (for example, naturopaths) family, friends, the media, and to a lesser extent their GP or a medical specialist.
Is wheat really so bad?
Up until recently it was thought that gluten was only really a problem for individuals with coeliac disease. Our findings, plus the extraordinary rise in popularity of the gluten-free diet in Australia and elsewhere, suggest that, apart from coeliac disease and wheat allergy, other conditions associated with the ingestion of wheat are emerging as health care concerns. Currently, the driver of most of the research activity in this area is the concept of non-coeliac gluten sensitivity (NCGS).
NCGS is defined as adverse reactions to the consumption of gluten, where both allergic and autoimmune mechanisms have been ruled out and where gastrointestinal symptoms improve on a gluten-free diet. Many aspects of NCGS remain unclear, including prevalence, clinical spectrum, physiological mechanism and treatment. There is also considerable debate as to whether it is in fact gluten or some other component of wheat that triggers the reported symptoms.
Fructans, for example, are short-chain carbohydrates which are found in wheat-based products, as well as other foods. For a proportion of the general population fructans, along with other short-chain carbohydrates (collectively called FODMAPS), can trigger symptoms like bloating, wind or cramps – by holding water in the gut or through the rapid production of gas by intestinal bacteria.
Our finding that people may be avoiding more than one dietary component at a time has the potential to complicate being able to know exactly which dietary components, and in what doses, are to blame for their symptoms. Further research is needed.
Until then, there is a risk that a significant proportion of Australians may be undertaking diets that are unnecessarily restrictive, with the potential danger of associated nutritional imbalances. Also of concern is the finding that the majority of symptomatic respondents appear to be bypassing conventional medical advice in their decision to go wheat-free. We would be remiss not to draw attention to the potential risk here of a serious clinical condition going undetected.
To find out more about our research into diet and lifestyle, visit our website.