Research suggests that gluten can cause headaches and other neurological symptoms.

Gluten is a protein found in various varieties of wheat, including spelt, barley, and rye.

Q: I get frequent, sometimes debilitating headaches. I'm also often depressed and have other baffling symptoms such as balance problems and numbness and tingling in my feet and toes (my physicians told me this is peripheral neuropathy). I have seen many doctors, and they say they can't find any reason for my chronic headaches or other symptoms. Is there any kind of nutritional treatment that might help? - Monica S., Atlanta

A range of dietary factors-from regular consumption of aspartame to eating foods that contain monosodium glutamate-can trigger headaches. However, one of the most common yet least-known ones is sensitivity to gluten, the problematic protein found in wheat, rye, and barley.

The other maladies you list have also been associated with gluten sensitivity. Unfortunately, many doctors--including neurologists--aren't up-to-date on research in this area, and thus aren't aware that neurological symptoms are often linked to adverse reactions to gluten.

Neurological Reactions to Gluten

Celiac disease is the most severe type of reaction to gluten: it's an autoimmune condition characterized by damage to the lining of the small intestine. Nonceliac gluten sensitivity also causes adverse symptoms, but not the intestinal damage seen in celiac disease.

Many different neurological symptoms have been documented and are much more common in patients with celiac disease. They include headaches and migraines; dizziness and balance issues; pain, numbness, or tingling in the extremities; and even cognitive impairment.

Scientists long assumed that celiac disease had to develop first before neurological issues manifest themselves. However, in 1996, a study by researcher Marios Hadjivassiliou of England found that neurological dysfunction can not only precede celiac disease, but can also be its only manifestation. More recent research by Hadjivassiliou showed that nonceliac gluten sensitivity is also associated with neurological dysfunction.

In fact, gluten sensitivity can be primarily-and at times, exclusively-a neurological disease. In other words, people with gluten sensitivity can have issues with brain and nerve function without having any digestive problems. In addition, the longer a gluten-sensitive individual with these conditions continues to eat gluten, the worse his or her condition tends to become. However, when gluten is eliminated from the diet, neurological issues often improve dramatically.

Studies Linking Gluten to Headaches

In one study, Hadjivassiliou examined 10 patients with gluten sensitivity and headaches. All of the patients had abnormal MRI tests that showed white matter characteristic of cerebral inflammation.

A gluten-free diet resulted in full or partial relief from headaches in nine of the patients over time. (One patient would not try the diet.)

In 2012, a year-long study by researchers at Columbia University Medical Center in New York documented chronic headaches among 56 percent of people who were gluten-sensitive and 30 percent who had celiac disease. The researchers also found that 23 percent of those with inflammatory bowel disease had chronic headaches.

The researchers alluded to inflammation as being the perpetrator of the headaches. The exact reason is still not known, what is known is that there is a higher prevalence of headaches, including migraines, in gluten-sensitive individuals.

In his book, Brain Maker, David Perlmutter, MD, makes the case that all of us may be gluten-sensitive to some degree, and gluten sensitivity increases the production of inflammatory cytokines, chemical messengers that contribute to neurological dysfunction and disease. The effects might start with headaches and later worsen into more dire disorders such as depression and dementia.

Rodney Ford, MD, of the Children's Gastroenterology and Allergy Clinic in New Zealand, agrees. He considers gluten sensitivity a neurological disease, and like Perlmutter, thinks everyone should avoid gluten for brain and nervous system health.

Testing for Celiac Disease and Gluten Sensitivity

If you suffer from unexplained headaches and other neurological symptoms, get a blood antibody test to screen for celiac disease and gluten sensitivity. Even if the tests are negative, try eliminating gluten from your diet and see if symptoms respond.

For some people, a gluten-free diet can result in a complete resolution of headaches. Many others report dramatic improvements in the frequency and severity of their headaches. With their condition so much better, they can then concentrate on finding other individual triggers.

A wide range of dietary triggers-including gluten-can cause headaches and other neurological symptoms.

Avoiding Gluten

There's a glut of gluten in modern food, and you have to go against the grain to avoid it. The gluey protein is found in foods that contain wheat, kamut, spelt, barley, rye, and triticale, and it's hidden in countless processed foods, including breads, baked goods, broths, soups, gravies, marinades, meatballs/meatloaves, soy and teriyaki sauces, seitan, and veggie burgers.

Among naturally gluten-free foods, it's important to know that gluten-free grains, seeds, and flours are most at risk for unwanted gluten contamination. If you choose to eat these foods, look for those that are processed in a dedicated gluten-free facility and have been batch-tested for gluten-or for products certified by the Celiac Support Association or the Gluten Intolerance Group (which certify foods that test below 5 or 10 ppm gluten).

The safest way to steer clear of gluten is to eat fresh fruits and vegetables and unprocessed meat, fish, and poultry (that are not injected with broth). They contain no gluten at all.