MSG and Headache – A Myth?

Late last year, an article in Lifehacker caught my attention – Stop Being Afraid of MSG. People with headaches and migraine may either be relieved or shocked by the claims that follow:

If you’re still afraid of the seasoning MSG giving you headaches, you should know you’ve bought into a decades-old myth.

Words like “afraid”, “bought into” and “myth” certainly make one feel like they should change their opinion immediately, and order a bottle of MSG (affiliate link conveniently provided in the above article).

But on the other hand, many headache sufferers swear that, every time they eat MSG, they get a headache.

So what’s the truth? First, in spite of the fact that MSG has sometimes pretty much been blamed for the imminent fall of civilization, it doesn’t seem to have an obvious, immediate effect on most people. And long term effects of that kind are extremely difficult to measure.

So the real question is, does it bother some people, perhaps those predisposed to migraine?

Almost anything bothers somebody, so we’re actually looking for something more widespread than 6 people in Berlin who get sick if they eat MSG.

So here’s what many of you really want to know. Yes, there are many people who feel that MSG gives them headaches. You will hear lots of stories. That doesn’t make it a fact, but it’s widespread enough that it seems to be more than a coincidence.

However, the clinical trials have not been conclusive. So why is that? Are the “right” people simply not in the trial?

Part of the challenge is that MSG is noticeable. That means placebo effect. So a well designed study is difficult to do with MSG, and trials in the past have often been poorly designed from a scientific point of view.

In 2016, a useful review of the studies of MSG was published in the Journal of Headache and Pain (Does monosodium glutamate really cause headache? : a systematic review of human studies). The study pointed out some of the problems with previous studies.

Falling short of claiming that MSG headaches are “myth”, the researchers concluded that the evidence was not strong enough from clinical trials to prove a direct causal relationship:

Because of the absence of proper blinding, and the inconsistency of the findings, we conclude that further studies are required to evaluate whether or not a causal relationship exists between MSG ingestion and headache.

Interestingly, the study actually interacted with the beta edition of the International Classification of Headache Disorders 3rd edition (ICHD-3 beta), which listed monosodium glutamate (MSG)-induced headache as one type of “Headache attributed to a substance or its withdrawal”. The cited studies were investigated more closely, and again, the studies did not seem robust enough to prove the relationship between MSG and headache.

The editors of ICHD-3 seemed to agree, dropping the mention of MSG altogether when the document came out of beta.

If someone gets a headache after eating foods with MSG, what does that mean? Is it possible that other issues (such as high salt content in general) could be causing the headache? In some cases, yet. It is easy for individuals to assume that one thing is causing their headache, when it’s something else altogether – and that’s something that happens frequently.

On the other hand, it would seem difficult to use these studies to “prove” that there is no causal relationship. So that leaves us with two practical issues.

First, you are the only one who is going to “test” the relationship on yourself. Keep an open mind, and if you’re convinced that MSG is a problem for you, stay away from it. If you’ve read the evidence and would like to give it another try, go ahead.

We should probably be a little cautious before we start labelling the MSG headache as a con or myth. And laughing at the silly woman who still lives in the bronze age and thinks that MSG causes her headache would seem to be counter-productive. We really don’t have the evidence to know if MSG bothers her or not. And when new research comes out, who knows if our minds will change.