High Vegetable Intake May Reduce MS Symptom Burden

Patients with multiple sclerosis (MS) with a plant-rich diet had less symptom burden, according to a study of dietary habits. The research, published in Neurology and Therapy, found an inverse association. As intake of vegetables increased, symptom burden decreased.

The study identified 3 dietary clusters using real-world observational data on food intake and MS-related symptoms for patients in Denmark.

There has been limited previous research on food intake and disease expression, the authors explained, and the results have been conflicting. “High-quality clinical trials are rare within the field of MS and diet, not least due to challenges in maintaining [persons with MS] on a specific diet during a long period of time,” they wrote.

In this study, patients logged daily notes on their food intake and MS symptoms over the course of 100 days, from November 2017 to March 2018. A total of 550 participants registered, although only 413 downloaded the diet tracker app, set up the app and the study server so they can exchange data, and had at least 1 active day, defined as a day they registered food intake and reported their symptom burden. The median number of active days was 25. Less than 1% had 100 active days.

Ultimately 163 participants met inclusion criteria and were included in the analysis. Individuals were placed into dietary clusters based on at least 85% of observation days to identify a consistent diet. The 3 dietary clusters identified were Western (elevated intake of red meant and processed meat products), plant-rich (elevated intake of vegetables, vegetable oils, and fruit), and varied (balanced between the other two clusters).

Based on the background information, participants in the Western dietary cluster were less educated and mainly lived in rural areas, while those in the plant-rich dietary cluster were younger, highly educated people living in the capital region.

All of the participants in the plant-rich dietary cluster had relapsed/refractory MS (RRMS). None of the participants in the plant-rich dietary cluster used aid equipment compared with 67.4% in the Western cluster and 64.9% in the varied cluster. Those in the Western dietary cluster were the least likely to be on disease-modifying therapy (67.4% vs 80.7% in the varied cluster and 76.5% in the plant-rich cluster).

The study evaluated the impact of diet on 9 pre-defined MS symptoms: bladder dysfunction, bowel dysfunction, dizziness, fatigue, muscle weakness, pain, sensory disturbances, spasticity, and walking difficulty.

For the 9 MS symptoms, there was a significant reduction in symptom burden for the plant-rich dietary cluster compared with the Western dietary cluster. A high intake of vegetables was associated with a 32% to 74% reduction in symptom burden compared with a low level of vegetable intake.

Both high and low meat intake were both associated with increased muscle weakness. However, medium levels of meat intake were associated with reduced muscle weakness.

The researchers noted that this study’s observational nature may result in bias due to uncontrolled confounders, although they tried to reduce the impact of this limitation by using inverse probability weighting. In addition, since food intake and symptom levels are both self-reported, recall bias may be a challenge; however, it was thought that the daily digital input of this information may reduce this challenge.

“Although the research design limits the possibilities of establishing causal inference, the results indicate that general guidelines for healthy diet may be relevant as a tool in coping with MS symptoms,” the authors concluded.