Wednesday, 10 January 2018

Is a gluten-free diet healthy if you don't have coeliac disease?

Coeliac disease, an allergy to gluten that causes damage to the intestine, affects 1% of Australians. But more than ten times this number, or around 11% of the population, follows a gluten-free diet by choice.

Gluten-free foods are frequently perceived as a healthier alternative, because of alignment with a “wellness lifestyle”. But is there scientific evidence to support this?


Are gluten-free diets healthier?
Recent large studies have not found health benefits for a gluten-free diet, and in fact the opposite may be true.

Researchers followed a group of more than 100,000 people in the US for nearly 30 years and found a gluten-free diet was not associated with a healthier heart. Another study suggests gluten may be beneficial because it lowers levels of triglycerides in the blood. These are “bad” fats that increase the risk of heart disease. Another large study has found an inverse association between gluten intake and type 2 diabetes. People with a lower gluten intake had higher rates of type 2 diabetes.

Why are gluten-free diets so popular?
Non-coeliac gluten sensitivity is different from coeliac disease. In coeliac disease, gluten intake causes damage to the intestine’s lining, which reverses with a gluten-free diet. In non-coeliac gluten sensitivity (also called “gluten intolerance”), symptoms like bloating and wind are common, but no intestinal damage or long-term health effects occur. One study of self-identified gluten-sensitive people showed there was no evidence for gluten alone being responsible, but potentially implicated a class of sugars called FODMAPs.  

Another reason people may report improvement when commencing a gluten-free diet is the exclusion of many other foods that are known not to be healthy, such as cakes, biscuits, crackers and beer. These dietary changes may also contribute to overall wellbeing.

So where to from here?
For people without coeliac disease, there’s no evidence to support claims a strict gluten-free diet is beneficial for health. It’s even possible the opposite is true, and the avoidance of dietary whole grains resulting in a low fibre intake may be detrimental.

Given gluten-free foods cost around 17% more, perhaps it’s time to reconsider a strict gluten-free diet chosen for health benefits alone, and instead include a diversity of gluten and gluten-free foods, with dietary variety as the key.

Dr Suzanne Mahady is a Gastroenterologist and Senior Lecturer in Epidemiology at our School.  This blog post is an abbreviated version of her 8 January 2018 article in the The Conversation.