Diet Tips:Are gluten-free foods actually better for you?

Journal review by Shirley Webber (Research dietitian)

The gluten-free diet has been getting a lot of attention for a number of years now. However, there is still some confusion about whether or not this is actually a healthy diet.

A gluten-free diet restricts wheat, barley, rye and oats. Following this diet is essential for those who are diagnosed with coeliac disease. For this small portion of the population, gluten can be damaging to the gastrointestinal tract. 

There are many other people following a gluten-free diet, whether it be due to suspected sensitivity to gluten, or just because they think it is a healthier way to eat. Studies have shown that gluten intolerance without coeliac disease is rare, so for many people following a gluten-free diet for other reasons, what impact does choosing gluten-free products have on their nutritional status?

A study by researchers from the University of Sydney recently considered the nutrient differences of major gluten containing food groups which included: dry plain pasta, breads, and ready-to-eat cereals. Comparisons were made by analysing the nutrition information panel on gluten-free products (those stating on the packaging that it is gluten-free certified) and gluten containing foods in this category. Nutrients were also compared using the Health Star Rating - a nutrient profiling initiative implemented by the Australian Government. 

Analysis of the three food categories showed that there was, in fact, a very similar nutritional profile for both the gluten-free and gluten containing foods, however, with one notable difference in the protein levels: gluten-free foods contained consistently less protein than gluten containing foods, in particular in pasta and bread. There was also variation in the fibre content of gluten versus gluten-free foods.

This study also considered discretionary foods which cover: cereal bars, cake mixes/cakes, sweet biscuits, ice cream, corn and potato chips, cured meats, sausages and hot dogs, and sugar based confectioneries. For four of these discretionary foods (cereal bars, cake mixes/cakes, sweet biscuits, and cured meats, sausages and hot dogs), the Health Star Rating did not change for gluten versus gluten-free products. In three of the categories (ice cream, corn and potato chips, and sugar based confectioneries) the total energy density was lower in gluten-free products than in gluten containing products. Despite slightly better nutritional quality in gluten-free options, overall discretionary foods are all high in sodium, saturated fat, and sugar.

This study highlighted that gluten-free doesn't mean healthier, particularly when looking at some commonly used cereals, pastas, and bread, which make up a big component of the Australian and western diet. More research needs to be conducted to assess the vitamin and mineral differences of these gluten versus gluten-free products.

Wu, J. H. Y., et al. (2015). “Are gluten-free foods healthier than non-gluten-free foods? An evaluation of supermarket products in Australia.” British Journal of Nutrition 114: 448-454.
 

Diet Tips:Research studies: Testing zonulin as a potential biomarker of gastro issues and investigating the neurobehavioral effects of gluten in NCGS patients

By Mary Ajamian (US Fulbright Scholar)

       

Alterations in zonulin as a potential biomarker of gastrointestinal dysfunction

and

Investigating the neurobehavioral effects of gluten in non-celiac gluten sensitivity

The research: Many individuals with non-coeliac gluten sensitivity (NCGS) have reported positive behavioural health benefits of following a gluten-free diet. Exorphin peptides derived from the digestion of gluten in the gut are a possible explanation of food’s ability to modulate brain function. These peptides exert marked effects on stress response, anxiety, memory, and emotionality as evidenced by behavioural tests in animal models, yet little is known about their role in human systems. These studies are exploring gluten and casein’s role in the neurobehavioral and extra-intestinal symptoms of NCGS. Furthermore, Mary is investigating whether zonulin, a protein involved in modulating intestinal tight junctions and micromolecule trafficking, is a useful biomarker of dysfunction in NCGS and gastrointestinal disease.

How it affects the public: Unlike celiac disease, biomarkers for NCGS are lacking and the underlying biological mechanisms are poorly understood. Globally accepted, definitive clinical criteria do not currently exist. Despite a lack of scientific understanding, international awareness of NCGS continues to grow. Millions around the world are believed to be gluten sensitive. Many self-diagnose by following a gluten-free diet and subsequently reporting amelioration of symptoms as well as an overall increase in feelings of well-being and positive behavioural health outcomes. These projects address the much needed scientific inquiry to understand how gluten affects neurobehavioral symptoms and to search for biomarkers of dysfunction in NCGS.

All of the profits from the Monash University Low FODMAP Diet app purchases go to further research studies at Monash Unviersity's Department of Gastroenterology.