There's no question that gluten can affect your neurological system: people with both celiac disease and gluten sensitivity report symptoms that range from headaches and brain fog to peripheral neuropathy (tingling in your extremities).
Neurological illnesses such as epilepsy, depression and anxiety also are common in those who react to gluten. In addition, a serious autoimmune condition called gluten ataxia affects a small number of people.
Finally, there are some hints that conditions such as schizophrenia and bipolar disorder also may be affected by gluten intake in a few individuals. However, it's not yet clear from the research who might be affected, and whether a gluten-free diet can help some people.
Here's a rundown of the neurological conditions impacted by gluten.
Depression, Anxiety Lead The List
Research shows that people with celiac disease suffer from much higher-than-average rates of depression and anxiety. In fact, one study found that about one-third or more of celiacs suffer from depression, and 17% may have an anxiety disorder.
People who test negative for celiac disease but who have been diagnosed with gluten sensitivity also report higher levels of depression and anxiety, although the links between the conditions are less clear because they haven't been studied.
It's not clear why gluten ingestion leads to these two neurological conditions. Researchers have speculated that gluten-related intestinal damage might lead to nutritional deficiencies that cause depression and anxiety in people with celiac disease (deficits in certain B vitamins can cause some symptoms). However, that wouldn't explain why people with non-celiac gluten sensitivity (who don't get intestinal damage from gluten) also suffer from those two mental conditions.
Some gluten sensitivity experts notably, New Zealand pediatrician Dr. Rodney Ford have hypothesized that gluten affects your brain directly to cause these conditions, but this theory hasn't been proven. Regardless, you're far from alone if you experience depression and anxiety from gluten.
More on gluten-related depression and anxiety:
Insomnia, Brain Fog, ADHD Also Commonplace
Many people with celiac disease and gluten sensitivity can tell quickly when they've accidentally been glutened: their brains cloud up and they feel less effective, even stupid and clumsy. This phenomenon, known as brain fog, hasn't been studied, but it's another extremely common symptom for both celiac and gluten sensitivity.
Attention deficit-hyperactivity disorder is another frequent complaint, in both adults and children those of us who have kids with gluten problems can attest that school performance is much better when their diets are free of gluten!
Headaches? Yes, absolutely. In fact, migraines are commonly mentioned as both celiac disease symptoms and gluten sensitivity symptoms up to one-third report experiencing this sometimes debilitating headache pain.
Finally, getting a good night's sleep may depend on whether you can steer clear of gluten-containing foods insomnia and sleep problems seem to crop up in regularity in many of us.
More on brain fog, ADHD, migraine and sleep problems:
Peripheral Neuropathy Also Common; Epilepsy, Vertigo Reported
Gluten also may affect whether your nerves and balance system function properly.
People who have celiac disease or gluten sensitivity suffer from high levels of peripheral neuropathy, which causes a tingling or "pins-and-needles" sensation in your feet and fingers. The sensation stems from damage to the nerves in your extremities, and the condition may improve once you go gluten-free.
Epilepsy, meanwhile, results when your neurons fire incorrectly, leading to seizures and potentially even unconsciousness. Celiac disease also has been associated with a rare constellation of epilepsy and bilateral occipital calcifications.
Finally, vertigo or a sensation of dizziness and spinning occurs due to a malfunction in the balance system housed in your inner ear. There are only two studies potentially linking Meniere's disease (a form of vertigo) with celiac disease, but anecdotal complaints of vertigo are frequent among celiacs.
More on peripheral neuropathy, epilepsy and vertigo:
Serious Psychiatric Illnesses: Schizophrenia, Bipolar
There have been many reports suggesting gluten could be implicated in two very serious psychiatric conditions: bipolar disorder and schizophrenia.
In bipolar disorder, there are a few studies that indicate people with celiac or gluten sensitivity may suffer from higher rates of the mental condition. There's also an intriguing study that looked at levels of antibodies to gluten in the bloodstream of people with bipolar, and found high levels in those in the midst of a manic episode.
In schizophrenia, meanwhile, there have been decades of speculation that eliminating bread from the diet of schizophrenics (which of course would eliminate gluten) can help. However, there's little solid evidence for this, and no indication of which schizophrenia patients might benefit. Most psychiatrists believe the percentage of people who might see an improvement of their schizophrenia symptoms while eating gluten-free is very small.
More on bipolar and schizophrenia:
Gluten Ataxia: Autoimmune Brain Damage
When gluten consumption causes your body to attack its own tissues, you suffer from a gluten-induced autoimmune condition. There are three of these: celiac disease (damage in the small intestine), dermatitis herpetiformis (damage to the skin), and gluten ataxia (damage to the brain).
When you have gluten ataxia, your immune system attacks your cerebellum, the part of your brain responsible for coordination. In many cases, the damage is irreversible, although a strict gluten-free diet can halt the progression of the condition.
Gluten ataxia is a relatively newly-recognized condition, and not all physicians agree it exists. In addition, the number of people who have it is thought to be very small. However, many more people with celiac or gluten sensitivity suffer from symptoms similar to those seen in gluten ataxia.
More on gluten ataxia:
Bottom Line: The Gluten-Free Diet May Help Your Neurological Symptoms
There's no question that celiac disease and gluten sensitivity can lead to a wide array of neurological problems and conditions. However, in most cases, you can reduce or even resolve your gluten-related neurological symptoms by following a strict gluten-free diet.