There is no cure (yet!) for multiple sclerosis, so it is instead managed with drugs to help mitigate the effects of the disease. Lifestyle adjustments, including a healthy diet, can also help. Now research finds that some healthy foods might be a problem for certain people who have MS.

It’s already known that certain environmental factors can trigger MS and/or make it worse. But until now, the association between one environmental factor—allergies—and MS has not been clear.

So researchers at Brigham and Women’s Hospital and Harvard Medical School had 1,349 adult MS patients fill out questionnaires about their current history of three kinds of allergies—environmental (dust, mold or hay fever), food (eggs, dairy, wheat, soy, fish, shellfish, fruits, nuts or other food) and/or drugs. The patients also had gadolinium-enhanced MRIs of their brains. These scans are taken to show lesions, which confirm that inflammatory cells have crossed into the central nervous system, as happens during an MS attack.

Results: Compared with patients who had no known allergies, patients with food allergies had 27% more MS attacks. The brain scans of these patients also were more than twice as likely to have MS lesions in their brains as patients without food allergies. No association was shown for environmental or drug allergies and either MS attacks or brain lesions. Note: The study authors point out that they did not distinguish between true food allergy and food sensitivity.

Researchers believe that inflammation may be one reason for the association between food allergy and MS activity and lesions. Since environmental and drug allergies did not have the same effect, the researchers believe that there may be a unique mechanism associated with food allergies and MS relapses. The researchers also suggest that having a food allergy may alter the gut microbiome and produce changes in brain chemicals that affect the central nervous system. This study did not investigate whether active avoidance of the allergen reduced risk. They hope to pursue this important question in future research.

MS is a progressive autoimmune disease of the central nervous system that destroys myelin, the protective covering of nerve fibers, and eventually destroys the nerves themselves. Symptoms include numbness or weakness on one side of the body, vision problems, tingling, pain, tremor, unsteady gait, slurred speech, fatigue, dizziness and bowel and bladder problems.

Typically, the disease is characterized by periods of relapse, when symptoms worsen and disease severity increases…followed by periods of remission, when symptoms typically clear at least partially. Besides taking drugs that can speed recovery from attacks and slow progression of the disease, certain supplements and lifestyle changes—such as avoiding stress, smoking, heat, infection and fatigue—can also help lessen its severity.

More research is needed to better understand the results of this latest study. But in the meantime, if you or a loved one has MS and a known food allergy (or sensitivity), in light of this research it makes sense to be even more scrupulous about avoiding your allergen. And if you have MS but aren’t sure whether you have a food allergy or sensitivity, it’s a good idea to discuss with your doctor whether you should be tested. Most adults with food allergies have had them since childhood—but food allergies can also start in adulthood.