Under the microscope: The good and evil gluten

But what is gluten, and why did it suddenly become the enemy?

Gluten is a protein found in wheat and other grains like barley and rye, and it’s one of the reasons why baked goods are so delicious. When we bake with gluten the individual proteins link together to form a mesh – and it’s this mesh that gives dough its elasticity and chewy texture. It’s also what stops bread and cookies from simply crumbling apart – gluten is the glue that holds them together.

And if you like a nice moist cake you can thank gluten for that as well. Gluten helps to absorb and retain water within food, preventing it from drying out.

Gluten makes food great – and if you don’t believe, just try a slice of gluten-free bread. The downside to gluten is that it makes some people really sick. 

My friend Richard has coeliac disease. It’s an autoimmune disease – which means it’s caused by his own immune system. Our immune system is designed to help protect us against infection by bacteria, viruses and other pathogens. One of the ways it does this is by producing antibodies which stick to these pathogens, neutralising them and targeting them for destruction.

When people with coeliac disease eat gluten, their immune system decides that gluten is a threat, and launches an all-out attack. It produces a bunch of antibodies to try and neutralise the gluten. But unfortunately these antibodies don’t just attack gluten – they also attack the cells lining the small intestine.

This damages the intestine, which is painful, and also a problem since the intestine is where we absorb most of the nutrients from our food. One of the ways coeliac disease is diagnosed is by taking a biopsy of the intestine and looking to see if the tissue is damaged. 

For people like Richard eating gluten doesn’t just make them feel bloated or a little nauseous – it makes them seriously unwell and can land them in hospital. So it is really important that they have a gluten-free diet.

But should the rest of us be jumping on the gluten-free bandwagon? 

There’s no evidence that gluten-free diets are a healthier alternative. Let’s face it, a gluten-free cake can contain just as much sugar and fat as a version containing gluten. Every café has a long list of gluten-free options, and supermarkets now have whole isles dedicated to gluten-free foods. There are even a few recent studies suggesting that long-term gluten free diets might be linked to other health issues, like an increased risk of developing type 2 diabetes.

And gluten-free food is definitely not healthier for your wallet – it can cost up to 17% more than similar foods containing gluten.