Can A DNA Test Reveal Food Intolerances? I Took One To Find Out

A lot of the common signs of food intolerance ― rashes, fatigue, bloating ― can feel a little bit vague and hard to pin down. 

After all, everything from our hormonal changes to the weather can affect how puffy and itchy we feel. 

With that said, I’ve always thought my (regular) stomach troubles might be down to something like gluten intolerance or lactose intolerance. My mother struggled with the former, and my dad had the latter problem. 

But are food intolerances genetic in the first place ― especially when we know being introduced to foods at an early age can help to prevent them?

I took a test from MyHealthChecked to see what my score told me, and spoke to an expert about why it worked.

How do genes affect food intolerances?

Speaking to HuffPost UK, MyHealthChecked nutritionist Isabella Ramos said their test’s aim isn’t to definitively confirm an intolerance or sensitivity but to see whether you’re predisposed to developing it. 

“The test looks at your genes to see if you’re more likely to have trouble with certain nutrients, like dairy, gluten, caffeine, alcohol, and sodium,” she said.

For instance, celiac is a genetic disease, but non-coeliac gluten intolerance can be harder to trace. However, Isabella says “variations in the HLA genes, which are linked to how your body reacts to gluten” can be measured. 

That means that if you have those variations (which I do ― my test found that I’m very likely to have a gluten sensitivity), “it means you might experience symptoms like diarrhoea, cramps, and fatigue when eating foods with gluten.” 

If you don’t have those variations, it’s pretty unlikely you’ll have an issue with gluten ― the test can’t definitively diagnose gluten intolerance, but it can help to rule it out.

So far as lactose intolerance goes, Isabella says that “most people who are lactose intolerant have a variation in a gene called MCM6, which affects the production of lactase (the enzyme that helps digest lactose in dairy products).” 

Their test checks for this variant too.

What’s the advantage of that? 

Testing your genes (it only requires a quick swab of the inside of your cheek) means you’ll have a better-informed starting point if you suspect something’s wrong.

For instance, my results said I’m not sensitive at all to booze or caffeine (makes sense ― I don’t think I’ve ever gotten a coffee buzz), but that I have a medium risk of sensitivity to lactose and sodium and a high risk of gluten sensitivity. 

So if I want to get to the bottom (no pun intended) of my tummy troubles, I have a list of foods and other triggers to try eliminating. 

Of course, you can also test for allergies via a regular allergy test through your GP if needed too, and some conditions like coeliac can be diagnosed via blood test.