Food allergies may be linked to more MS relapses

• Due to the immune system playing a role in both MS and allergies, researchers investigated whether there are any links between allergies and MS disease activity.
• Results from this study, which involved more than 1,300 people with MS, showed that people with food allergies have more clinical attacks and lesions in the brain than those with other forms of allergies or those without allergies.
• These findings point to future avenues of research to develop our understanding of how the immune system works in MS. The mechanisms behind MS onset and progression involve a complex mix of genetic and environmental factors, which researchers are continually trying better understand.

The immune system is a particular focus in MS research, as we know that it mistakenly attacks the protective myelin sheath which coats the nerve fibres in people with MS. However, it is what triggers this autoimmune response is not clear.

In addition to its involvement in MS, the immune system also plays a role in other conditions. Therefore, researchers are investigating whether there are links between MS disease activity and other conditions involving the immune system, such as allergies.

In a recently published study, scientists at the Brigham and Women’s Hospital, Boston, USA, studied the link between allergies and MS. This investigation was part of a large, long-term study taking place at the MS clinic (known as the Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women’s Hospital or CLIMB).

More than 1,300 people with MS completed a questionnaire outlining their food, environmental and/or drug allergies. Each person’s MS activity was assessed by recording the number of clinical attacks experienced throughout the entire course of their disease. The severity of clinical symptoms during the most recent visit to the clinic was also recorded.

Additionally, the lesions in the brains of participants were monitored using Magnetic Resonance Imaging (MRI). The study used a specific MRI technique known as Gadolinium (Gd) enhancement, which helps experts spot the active inflammatory phase of lesion development. The number of new lesions in the brain observed 90 days before and after the completion of the allergy questionnaire were monitored and used as indicators of MS disease activity.

Results showed that people with MS who have food allergies have a significantly higher number of MS attacks, and more than twice the likelihood of developing new lesions compared to those without allergies. People with other forms of allergies (not related to food) showed no significant difference in their MS symptoms.

While this study demonstrates an association between food allergies and MS disease activity, it does not necessarily confirm that food allergies cause MS or cause more frequent attacks in MS. Moreover, the study also relied on people’s recall and self-report of food allergies, rather than clinically confirmed allergies. Despite this, the results do suggest that there is a potential link. The research discusses the possibility that food allergies may affect the balance of gut bacteria which in turn can affect the immune system, or that the allergies may directly affect the regulation of the immune system.

While more studies are needed to confirm these findings and identify the biological mechanisms involved, the results open a new avenue to develop our understanding of how the immune system works in MS.

For people with MS who suspect they may have food allergies, it is important to consult health professionals for a clear food allergy diagnosis and for support in identifying appropriate strategies to avoid the allergens. Cutting out broad food groups without a diagnosis and nutritional advice could result in deficiencies in important nutrients.

With thanks to MS Research Australia – the lead provider of research summaries on our website.