Does A Low-Gluten Diet Mean Higher Diabetes Risk?

| March 31, 2017

Gluten-free diets have become very popular and, as I explained in an earlier post here, there are good reasons why avoiding wheat and other gluten grains could be beneficial for blood sugar control. So, I was surprised to see a recent headline “Low gluten diets linked to higher risk of type 2 diabetes”.

This referred to a Harvard University study that made the connection after examining food questionnaires and health records from more than 300,000 people. The researchers, who presented their findings to a meeting of the American Heart Association, found that individuals with the highest gluten consumption had a 13 per cent lower risk of developing type 2 diabetes, compared to those eating the least gluten.1

The popular press seized on these findings, which appear to support the view that following a gluten-free diet without a good medical reason can be a dangerous fad. But you can’t always believe what you read in the newspapers. A closer look at this study shows that it was “observational” – in other words, it examined records that dated back more than 30 years and attempted to make correlations between specific dietary factors and disease. This kind of study can never give clear results, it can only suggest possible links.

In this case, there was plenty of room for error. Those participants in the study whose diet was low in gluten were probably not consciously choosing low-gluten foods. Remember, all this was happening long before low-gluten diets became popular and supermarket shelves became stacked with gluten-free alternatives. So, what were they eating that made their diets lower in gluten?

Well, a typical fast-food meal of a burger, chips, ice cream and a regular soda, doesn’t contain a lot of gluten. On the other hand, a plate of wholemeal pasta could give your gluten intake quite a boost. In fact, the Harvard researchers themselves were quick to point out that “Gluten-free foods often have less dietary fibre and other micronutrients, making them less nutritious”.

So, could it just be that the people in this study who ate the most gluten had a healthier diet that included plenty of fibre-rich wholegrains, while those eating the least gluten were stuffing down the fries and sugary drinks? Hey, presto! A low-gluten diet suddenly becomes the suspect in type 2 diabetes, when the real culprit is far more likely to be low-fibre, high-sugar (and high-fructose) junk food.

This sort of distorted conclusion can easily be made when one dietary component is taken in isolation, without considering other aspects of the diet. This study does not demonstrate that gluten has a protective effect against type 2 diabetes, and it should not make you worry if you are following a low-gluten or gluten-free diet.

The reality is that, even for people without coeliac disease, gluten can cause serious digestive problems, migraines, chronic fatigue, joint and muscle pain, brain fog and depression. Gluten may play a role in the development of type 1 diabetes – and, in animal models of type 2 diabetes, a gluten-free diet has been found to improve glucose tolerance and increase the volume of insulin-producing beta cells in the pancreas.2,3

Keeping your gluten intake low as part of a healthy, low-carb diet really is the best way to go. And new findings show that, for men at least, making the last meal of the day a low-carb one can make a big difference to blood sugar control, as I report in my next blog post.

Wishing you the best of health,

Martin Hum
PhD DHD Nutritionist
for Real Diabetes Truth

Bear in mind we are not addressing anyone’s personal situation and you should rely on this for informational purposes only. Please consult with your own physician before acting on any recommendations contained herein.


1. Zong G, Lebwohl B, Hu F et al. Associations of gluten intake with type 2 diabetes risk and weight gain in three large prospective cohort studies of us men and women. Circulation. 2017; 135(Suppl 1):A11.

2. Antvorskov JC, Josefsen K, Engkilde K, Funda DP, Buschard K. Dietary gluten and the development of type 1 diabetes. Diabetologia. 2014; 57(9):1770-1780.

3. Haupt-Jorgensen M, Buschard K, Hansen AK et al. Gluten-free diet increases beta-cell volume and improves glucose tolerance in an animal model of type 2 diabetes. Diabetes Metab Res Rev. 2016; 32(7):675-684.

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Category: Diabetes Risks

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