Tuesday, October 27, 2009

Gluten free

Trend, friend or foe?

Towards the top of food trend prediction lists over the past few years, gluten free products have made a grand entrance, but are they here to stay? This once niche market, come latest food trend, is taking up more space than ever on supermarket shelves with statistics from the US suggesting the gluten free market has grown exponentially by 30% each year, for the past 5 years.
A gluten free diet is an essential part of the management of coeliac disease (pronounced seel-ee-ak) and non-coeliac gluten intolerance, but it offers no specific benefit for the average healthy consumer. Coeliac disease is an inherited autoimmune disorder which, in the presence of gluten, causes the small intestine to become inflamed and lose its ability to absorb nutrients from food. Gluten is the protein found in foods containing wheat (and wheat-related grains such as spelt), barley, oats and rye.
Around 1 in 100 Australians have coeliac disease, but many more may be unaware they have it - the Coeliac Society of Australia estimates 75% of people with the condition remain undiagnosed. Correct medical diagnosis by small bowel biopsy is the first step in deciding if a life-long strict gluten free diet is necessary.
In addition to those with coeliac disease, the number of people believing they are gluten intolerant appears to be growing. Whether this represents a true increase, or is due to more people being tested, better technology, and/or larger numbers of people being misdiagnosed or self-diagnosed remains unclear.
Gluten free diets are often claimed to assist in the treatment of disorders such as autism, multiple sclerosis and attention deficit disorder. While there are proponents of such treatments, the scientific evidence to support the use of gluten free diets for situations other than coeliac disease or gluten intolerance is generally lacking.
Whatever the reason, interest in gluten free diets has 'boomed', fuelled by the combination of much greater availability of gluten free products (resulting from food manufacturers responding to market opportunity) and increased media attention on the issue. This increasing interest may be falsely interpreted to imply that gluten free foods are better for us, whereas in fact, these products do not offer any additional health benefits over regular products for people who are not gluten intolerant.
From a dietary perspective, gluten free products can be expensive, are often lower in dietary fibre and wholegrains, and bread made from these grains will not be fortified with folic acid. Gluten free grains such as rice, corn, quinoa (pronounced keen-wa), buckweat and amaranth provide dietary fibre, vitamins and minerals, (especially in their wholegrain form) but it can be challenging to achieve a nutritionally adequate diet using ingredients that are less familiar and that may not have the same functionality in cooking. Check out the recipes section of the Go Grains website for some delicious recipes using rice and quinoa.
Australian dietary guidelines recommend that a diet for healthy adults, teenagers and children should include 'Plenty of cereals (including breads, rice, pasta and noodles), preferably wholegrain'. Whether you are four, fourteen or forty, aim to include at least '4+serves a day' of grain-based foods in your diet.
If you suspect you may have coeliac disease, it is best not to self-diagnose. Don't go 'gluten free' before you see your doctor to confirm the diagnosis. If the diagnosis is positive, arrange to see an accredited practising dietitian (APD) who will help plan a balanced diet.
Useful references:

Bread to boost brain performance

Bakers required to use iodised salt in bread

In last month's E-News we wrote about the new mandatory addition of folic acid to wheat flour for bread-making, introduced to help reduce the incidence of neural tube defects in babies. This month we can report that bread has also become a source of iodine - 3-4 slices (100g) of bread now provides around 46ug of iodine. A seemingly micro amount, this is actually almost one third of the daily requirement of iodine for Australian adults and over one third of the recommended amount for children. This is a step in the right direction to help combat the world's most preventable cause of mental retardation - iodine deficiency.

Mandatory fortification of all commercial breads (except organic bread) with iodised salt came into force on 9th October 2009. No additional salt is being added to bread, bakers will simply use iodised salt instead of standard salt hoping to reduce a re-emergence of iodine deficiency amongst many Australians. We only need about 1 teaspoon in a lifetime, however iodine is an essential trace mineral needed for regulation of normal growth and metabolism and is crucial at certain stages of foetal development during pregnancy and early childhood. The body can only store a small amount and regular top ups are needed from a variety of foods in a healthy balanced diet. Iodine is naturally found in foods such as oysters, fish, tuna, sushi (seaweed), dairy products and eggs.

A recent study published by Gordon et al in the American Journal of Clinical Nutrition, found that iodine supplementation can improve cognition in even mildly deficient children. This is good news considering the National Iodine Nutrition Study conducted in 2003-04 found that mainland Australian children on average are borderline iodine deficient, with NSW and Victorian children being mildly iodine deficient. Although the amount supplemented in this study was three times greater than the amount now found in 100g of bread (fortified with iodised salt), Food Standard Australia New Zealand (FSANZ) expects mandatory iodine fortification to reduce inadequate iodine intakes from 43% to less than 5% in the Australian population.

Useful references:


Creswell et al. Are Australian children iodine deficient? Results of the Australian National Iodine Nutrition Study. MJA 2006;184:165-169.

Gordon et al. Iodine supplementation improves cognition in mildly iodine-deficient children. AJCN 2009;90(5):1264-1271.