The Link Between Gluten and Migraines

I began experiencing migraines and persistent headaches in my late 20s — one of the earliest signs of what I would later discover to be gluten sensitivity. The pain was most often triggered by sunlight, especially harsh sun glares that entered directly through my eyes. It would begin as a tension behind my eyes and gradually intensify, escalating into a throbbing, sometimes debilitating headache that could last for over a day. These migraines were not only intensely painful but would also lead to nausea and vomiting, making it impossible to carry on with daily activities.

In those moments, the slightest movement of my head would result in a deep throbbing pain. The only thing that could dull the pain was paracetamol and not moving my head completely. Sleep, which typically helps the body recover, wouldn’t help either, as the pain would persist through the night, leaving me exhausted and helpless.

Photo: woman holding her temples.

At first, I assumed these migraines were caused by excessive screen time. And while prolonged computer use did cause eye strain and dryness, it never led to full-blown headaches. Over time, I realized the migraines were specifically tied to sunlight exposure, not digital fatigue.

By my mid-30s, sunglasses became a permanent fixture in my life. I wouldn’t leave the house without a pair. At work, where wearing sunglasses wasn’t an option, I made a point to avoid sitting near windows or facing direct sunlight. Even a few seconds of glare through glass could trigger a migraine. If I were meeting someone for coffee or lunch in a glass-panelled café, I would always request a seat with my back to the window, because light filtered through glass seemed to make the pain even worse.

Driving during the day became another hurdle. I couldn't drive without sunglasses, not just because of the brightness, but because sunlight had become a very real health threat to me. Living in Singapore, with its intense year-round UV levels, I chalked it up to sensitivity to the climate. I did not know that something deeper was going on.

The Gut-Brain Axis: A Hidden Link

Everything began to shift when I started my unglutening journey. One of the first changes I noticed was the disappearance of my migraines and headaches. For the first time in years, I could step outside without shielding my eyes. I could drive without sunglasses, go to the beach without fear, and sit in a glass-panelled café overlooking the beautiful city view of Singapore. I could do all these without worrying about a sudden, stabbing pain behind my eyes.

This prompted me to dig deeper. As I researched the relationship between gluten and neurological symptoms, I discovered the role of the gut-brain axis - a two-way communication network between the gastrointestinal tract and the central nervous system. But what truly changed my understanding was learning how gluten can damage 3 critical protective systems in the body: the gut immune barrier, the gut-brain axis, and the blood-brain barrier.

Gluten and the Breakdown of the Body’s Protective Barriers

In individuals with celiac disease or non-celiac gluten sensitivity, gluten triggers an immune response that disrupts the gut lining. It increases the production of zonulin, a protein that loosens the tight junctions between cells in the intestines, leading to what is known as “leaky gut.” This allows gluten fragments, bacteria, and inflammatory molecules to pass into the bloodstream - breaching the gut immune barrier.

Once in circulation, these inflammatory molecules can compromise the blood-brain barrier (BBB), the brain's security system that protects it from harmful substances. A weakened BBB allows toxins and immune signals to enter the brain, triggering neuroinflammation. For people like me, this inflammation manifests as extreme light sensitivity and debilitating headaches. What I once thought was just “sunlight sensitivity” was actually the symptom of deeper immune dysfunction caused by gluten.

Over time, I also came to understand that gluten sensitivity affects more than just immune pathways - it also interferes with nutrient absorption. For instance, magnesium, a mineral critical for calming nerve impulses and stabilizing blood vessels, is often poorly absorbed by those with gluten-related disorders. A deficiency in magnesium can make the brain far more reactive to stressors like light. This likely explained why sunlight, something so benign for most people, became a migraine trigger for me.

Gluten sensitivity can also interfere with the absorption of other nutrients, such as B vitamins, vitamin D, and omega-3 fatty acids. These nutrients are all vital for nerve function and inflammation control, and a deficiency can lower your brain’s resilience, making it more prone to environmental triggers like UV light.

Compounding the problem is the inflammatory response gluten sets off; systemic inflammation from gluten doesn’t just affect the gut, it primes the entire nervous system. UV exposure contributes to oxidative stress, and when combined with gluten-triggered inflammation, this leads to heightened sensitivity of the trigeminal nerve - the nerve most involved in migraines. When this nerve is inflamed, even brief exposure to sunlight can result in intense headaches.

Another major player in this puzzle is neurotransmitter imbalance. Gluten sensitivity disturbs the gut microbiome, which produces most of the body’s serotonin and helps regulate melatonin. Serotonin is key to mood and migraine regulation, while melatonin governs our sleep-wake cycle. A disrupted microbiome means fluctuating neurotransmitter levels, which when combined with sunlight exposurel can create a perfect storm for migraines.

Benefits of Unglutening

The combination of gut barrier damage, nutrient malabsorption, chronic inflammation, and disrupted brain chemistry creates a hypersensitive nervous system. When you add sunlight exposure into this mix, it becomes a major trigger. In this inflamed and overstimulated state, even three seconds of harsh sun glare could push me into a full-blown migraine.

Addressing my gluten sensitivity not only resolved my migraines but also gave me a new understanding of how interconnected our systems are. I certainly did not know that the brain and gut were connected prior to my unglutening journey - or that all inflammation truly begins in the gut.