Are gluten free diets just a fad?
Gluten is a protein that's found in wheat, rye and barley and can also be found in some oatsi. For people with coeliac disease, all foods containing gluten must be avoided because their immune system reacts to the protein, attacking the lining of the gut wall in a way that can result in serious small bowel damageii.
Less than one per cent of Australians have been diagnosed with coeliac disease, although from the amount of gluten free products on supermarket shelves one could guess it was much moreiii. The fact that the supply of gluten free products is increasing drastically may imply that lots of Australians who aren't coeliac are choosing to cut out gluten for other reasons.
Results of the 2011-12 National Nutrition and Physical Activity Survey (NNPAS) suggest that almost 2.3 million Australian adults reported being on a diet and almost four million people reported avoiding a food type, with cow's milk and gluten being the two most commoniv.
What does gluten intolerance mean?
Some recent studies have suggested that many people who are not coeliac may not be able to tolerate gluten. People with gluten sensitivity don't have an immune system response to gluten the way that individuals with coeliac disease do, and they also don't have an allergy to wheat, but they do experience some very unpleasant symptomsvi.
If someone has gluten intolerance, after eating anything containing gluten they'll experience issues ranging from abdominal cramping to bloating, diarrhea and flatulencevii. Researchers have also suggested that people with gluten sensitivity or intolerance may experience side effects from eating gluten that go beyond digestive reactions. These include headaches, fatigue and depressionviii.
There are lots of explanations for the sudden growth in the number of people who experience gluten intolerance - one possible cause is the fact that selective breeding of wheat has created wheat varieties that are higher in gluten than ever before. This is because high-gluten crops attract less pests and also produce bread which is lighter and fluffiervi.
Controversy surrounding gluten sensitivity
There has been much controversy surrounding gluten sensitivity and a number of studies have been conducted with differing results. Take Australian scientist Peter Gibson's research for example. In a 2011 study, Gibson found that gluten could cause gastrointestinal distress in people without coeliac disease.
However, a new 2014 study by Gibson found no direct link between increased gluten intake and gastrointestinal distress for subjects identifying as gluten intolerant. In fact, each diet used in the 2014 study, whether it included gluten or not, caused subjects to report a worsening of symptoms including pain, bloating, gas and nausea. These results could indicate a nocebo effect - the subjects expected to feel worse and so they didix.
Gibson's team is now exploring the possibility that the subjects reacted badly to the short-chain carbohydrates that form the group of compounds commonly known as FODMAP - or Fermentable, Oligo-, Di-, Mono-saccharides and Polyols -, which could also explain the unpleasant symptoms people with gluten sensitivity experience. If FODMAPs are what people are reacting to, then a gluten free diet may make them feel better because the largest source of FODMAPs in our diets is found in bread productsix.
Does gluten free mean healthier?
The Australian gluten-free industry is projected to be worth $105 million by 2015 . With so much money to be made from the gluten free "craze", it can be difficult to separate facts from marketing when you're trying to make healthy choices in the supermarket. Some companies are even labelling foods that never contained gluten as being "gluten free", for example, you can find the gluten free symbol on packets of rice and olives.
For those who don't have coeliac diseases or gluten sensitivity, choosing one of the gluten free options - which are becoming increasingly common - is unlikely to have any benefit. Many packaged and processed foods that are marketed as being gluten free, like pizza crust or brownies, are still high in sugar, fat and calories. So gluten free does not necessarily mean healthy. There's also no reason why cutting gluten out of your diet should help you lose weight, without making other changesvii. With that said, the current popularity of gluten free food is great news for anyone with coeliac disease or gluten sensitivity, who have more options when they go grocery shopping than ever before.