Over 400,00 people in the United States have multiple sclerosis (MS), an autoimmune disease that attacks the protective covering around nerve fibers, potentially causing enough nerve damage to leave a person severely disabled. While the cause of the disease is not known and there is no treatment beyond slowing the progression of the disease and managing symptoms, new research suggests that a healthy diet may result in fewer symptoms and less disability.

“People with MS often ask if there is anything they can do to delay or avoid disability, and many people want to know if their diet can play a role, but there have been few studies investigating this,” study author, Kathryn C. Fitzgerald, of Johns Hopkins School of Medicine, said in a statement.

People who led an overall healthy lifestyle had less depression, severe fatigue and pain than those whose lifestyle was not considered as healthy.

Nearly 7,000 people with all types of MS took part. After completing questionnaires about what they ate, participants in the study were divided into five groups corresponding to the healthfulness of their diet. A healthy diet was considered one that included plenty of fruits and vegetables, legumes and whole grains, with far smaller amounts of sugar, red meat and processed meat.

The participants' lifestyles were also evaluated. Those who were a healthy weight, got regular exercise, had a better-than-average diet and were not smoking were considered to have a healthy lifestyle.

Finally, the MS patients in the study were questioned about the symptoms of multiple sclerosis they had experienced during the previous six months. Had they had a relapse of symptoms? Had their symptoms worsened? What was their level of disability? How severe was their fatigue, mobility issues, pain and depression?

Despite adjusting for factors that could impact disability like age and length of time with MS, researchers found the people who ate the healthiest were 20 percent less likely to have more severe disability and depression than those who had the least healthy diets.

The healthiest diets contained approximately two servings of whole grains per day and three servings of fruit, vegetables and legumes, while the least healthy diets consisted of only a third of a serving of whole grains and 1.7 servings of fruits, vegetables and legumes. French fries were not counted as a vegetable.

People who led an overall healthy lifestyle had less depression, severe fatigue and pain than those whose lifestyle was not considered as healthy.

While the study doesn’t prove that healthy eating or a healthy lifestyle reduce the symptoms of MS, it does suggest eating and living healthy may offer some protection from severe disability.

The study is published in Neurology.