The Gluten Free Diet: for better or for worse?

I'm still processing last month's anti-gluten Twitter campaign from ex-Dragon Duncan Bannatyne - a man who, remember, warned hundreds of thousands of followers against accepting nutritional advice from dietitians trained to give it, and in the same unqualified breath dished it out himself. Failing to see the irony - perhaps due to a surprisingly mediocre intellectual capacity which revealed itself along with an almost comic unpleasantness - he refused attempts to be reasoned with, as countless coeliacs and nutrition experts learned. The futility of trying to make him see sense eventually dawned: we were challenging someone to a battle of wits - but who turned out to be unarmed.

In the discussions which followed, the question of whether the gluten free diet (GFD) was better or worse than the gluten-containing diet (GCD) cropped up a fair bit. This is a vexed issue, because no two people's diets are identical, and although we all need the same nutrients to stay alive, different individuals need different levels, depending on size, age, sex, health profile, etc.

GFD vs GCD - which wins? 
I fell into an exchange with someone who argued, because he'd been following a GFD for years, with no ill effects, that the diet was not nutritionally poorer. This was a flawed argument, because it was a conclusion drawn from the experience of just one person - himself. I'm always surprised when people fail to grasp they don't get to decide on the truth or falsehood of a medical matter, any more than their vote gets to determine the outcome of an election. I may as well argue that because I didn't vote Conservative in May, Cameron didn't win. You see this failure of logic regularly in discussions about food intolerance tests: 'I took a test and it worked for me therefore these tests work'. Wrong.

It's the big picture we need to explore - lots of people. And we need measurements. An election is easy: everyone gets one vote. But nutrition is complicated. What to measure?

There are two things:
1/ The nutrient content in GF foods versus comparable GC foods;
2/ The nutritional intake of GFD followers versus GCD followers.

Let's look at the first of these.

This study in a Canadian Journal of 130 GF and GC foods concluded that packaged GF foods were higher in fat and carbohydrates, and lower in protein, iron and the B vitamin folate, which a study by nutritionist Tricia Thompson also foundThis study found that GF breads were higher in fat, lower in protein, and higher in glycaemic index values than GC breads.
GF foods: on average, higher in fat and sugar

Let's look at the second.

This study found half of those on a GFD for 10 years had a poor vitamin status. This one, on children, found GF kids had higher carb intake and lower folate. 'Dietary inadequacies are common' reported this UK study (which recommended fortification of GF foods). This German research found that coeliacs on the GFD had lower than national average intakes of B vitamins, iron and magnesium. 'Following a diet based on GF foodstuffs could suppose a nutritional imbalance in celiac patients as well as non-celiacs who follow a diet that includes many GF rendered foodstuffs' - was the conclusion of this Spanish research, and this one found that trace mineral intake was worryingly low in men and women on the GFD. The GFD may even negatively impact the microbiome and your immunity.

There are more out there.

So what do such studies mean? 
Here's what they don't mean.

They don't mean that your GFD is necessarily bad, or that your best friend's GCD necessarily good. They don't mean my GCD is better, the same or worse than your GFD or your neighbour's GFD. They don't mean that a nutritionally adequate or even excellent GFD is impossible.

They do mean that, given our particular food culture, and typical diets, and available products on our shelves, and lifestyles, the average GFD is less likely to be nutritionally complete, more likely to have unhealthy quantities of sugars and fats, less healthy overall, and tougher to follow, than a GCD.

These are the consistent findings of many Western studies, of the many researchers and scientists who have conducted them, and on which experts such as dietitians' opinions are based.

They get to decide - not you nor I - and until Western diets alter drastically and the nutritional profiles of the free-from foods on our shelves improve via fortification or otherwise, this is the way it will remain.

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