A new study found patients who ate mostly fruits and vegetables had improved disability scale scores and fewer relapses compared to patients on a traditional Western diet.
Mario Clerici, MD
Switching to a high-vegetable, low-protein diet could be beneficial for patients with relapsing-remitting multiple sclerosis (RRMS), according to a new study.
The dietary changes appear to work by regulating the gut microbiome, which in turn modulates the immune system and produces anti-inflammatory bacteria. The findings are based on a small study of 20 patients with RRMS who tried 2 alternate diets for a year.
Study co-author Mario Clerici, MD, professor of immunology and immunopathology at the University of Milan, said they chose to initially study RRMS patients because it provided the clearest picture of potential dietary impacts.
“We first worked on RRMS because it is the most common form of the disease and because, from an experimental point of view, it is a perfect model to verify whether a therapy or, in this case, a dietary regimen can have a positive effect (i.e. a reduction of the active phases of disease),” Clerici told MD Magazine.
The researchers lined up 20 patients from the Don Carlo Gnocchi Foundation, where Clerici heads the Department of Molecular Medicine and Imaging in Rehabilitation. Each patient had disease stability for at least 6 months prior to enrollment, and none had disease-modifying therapy (DMT) during that time period.
The scientists also excluded patients who had taken immunosuppressants or teriflunomide, and those with significant comorbidities.
The cohort was split in half and given a new dietary assignment. One group was told to focus on fruits and vegetables and strictly limit animal products. Participants were told to eat fish no more than twice a week, chicken no more than once per week, no more than 4 eggs per week, and dairy no more than once per week.
These patients also were told to limit processed and fried foods, and abstain from alcohol, red meat, and trans fats.
The other patients were put into a “Western diet” group, which was given free reign to eat foods like refined grains, sweets, and red meat.
The patients met face-to-face with a nutritionist every four months to ensure adherence.
Blood and fecal samples were taken at the start of the study and after 12 months. Neurological examinations were performed at the same intervals.
Over the course of those 12 months, researchers noted that the patients with the high-vegetable, low-protein diet had higher levels of Lachnospiraceae bacteria, which are believed to strengthen the immune system and fight inflammation.
Moreover, those with the plant-based diet had improved scores on the Expanded Disability Status Scale (EDSS), whereas those eating a Western diet saw their EDSS scores fall.
By follow-up, 9 of the 10 patients on the Western diet experienced relapses, while only 3 of the plant-based diet experienced relapses.
Clerici said more study is needed to better understand the mechanisms at play with the clinical benefits. He also hopes to find out if the dietary changes would have a positive effect on patients with primary progressive MS (PPMS).
“I would not be surprised if this diet could modulate disease progression in PPMS as well: in PPMS degeneration is prominent, but a degree of inflammation is observed as well,” Clerici said. “The diet could be beneficial by reducing inflammation and by augmenting the production of neurotropic factors.”
The researchers are already in the midst of a follow-up study, this time including 12 patients with PPMS.
The study, "Immunological and Clinical Effect of Diet Modulation of the Gut Microbiome in Multiple Sclerosis Patients: A Pilot Study," was published online in Frontiers in Immunology.