Nutrition research can make for attention-grabbing headlines. Here, we cut through the hype – and clarify the real take-home message – for you.
Does going gluten-free mean a higher risk of type 2 diabetes?
Gluten-free diets have surged in popularity recently. Yet most people who follow them lack any valid medical reason to be cutting gluten-containing foods from their diet. A recent observational study from the United States has now raised the spectre that following a gluten-free diet could elevate the risk of developing type 2 diabetes.
Coeliac disease is linked with a higher risk of type 1 diabetes, but type 2 diabetes is a very different disease in its causes. So, research finding that a gluten-free diet raises the risk of type 2 diabetes is important for the broader population who do not need to follow such a diet. What surprised me most about the study was the level of media attention it garnered for what was a conference presentation at the American Heart Association conference, rather than a full published paper.
The hype: How the media conveyed the news
The media ran with headlines putting the risk of diabetes by going on a gluten-free diet firmly in their crosshairs. A gluten free diet could increase your risk of diabetes (Huffington Post), Gluten-free diet increases the risk of getting type 2 diabetes, according to a new study (News Ltd) and Gluten-free diet could be linked to type 2 diabetes risk, study suggests (ABC News). Digging past the headlines, though, I found more balance and context. Each of the stories made the distinction between people who need to follow a gluten-free diet because of having coeliac disease and those that choose to avoid it more as a lifestyle choice. The stories also linked the likely explanation for the higher type 2 diabetes risk to less cereal fibre being eaten which is plausible.
The truth: The research findings
The research study that generated so much media interest combined data from three long-running cohort studies. From food frequency surveys of almost 200,000 people, estimates of gluten intake were made every 2 to 4 years. People with the highest intake of gluten had a 13 percent lower risk of developing type 2 diabetes, compared to those eating the least.
If having less gluten does increase the risk of type 2 diabetes, it is unlikely to be from any inherent protective effect of gluten. The most likely explanation is that gluten is a marker for many of the nutrients found in foods containing it. Wholegrains stand out here. Consuming plenty of wholegrain foods appears a key factor in reducing the risk of type 2 diabetes when eaten in place of highly refined grains.
We will need to wait for the full paper to be published for deeper analysis. But it may go on to show that a low-gluten diet was a marker for more discretionary foods or a diet that was lower in fibre.
The reality: Putting the findings into practice
The study is a good example of unintended consequences. For people with no clinical reason to avoid gluten, following a gluten-free diet for its perceived health benefits could do more harm than good if it is not done with the whole diet in context. If gluten-containing foods are excluded, then swap them for similar wholegrain foods such as corn, brown rice, buckwheat, quinoa and millet. This brings in the key role of a dietitian in advising what foods to have more of, as a substitute for gluten-containing foods, if a person is set on following such a diet without a clear medical reason.
Tim is an Advanced Accredited Practising Dietitian, and career nutrition research scientist and media communicator. Connect with him at www.thinkingnutrition.com.au.