MS is a neurological condition of the brain and spinal cord. It affects muscle control, vision and balance and causes fatigue, loss of sensation, and numbness.
MS is an autoimmune disease in which the body's immune system wrongly turns on itself, attacking the covering of nerves, called the myelin sheath. This means that signals to and from the brain can be disrupted.
There are 5 types of MS. The most common – affecting around 85% of patients – is relapsing remitting MS, in which symptoms appear and then disappear completely or partially.
MS affects around 100,000 people in the UK.
The study led by John Hopkins School of Medicine, Baltimore, involved 6,989 people with all types of MS who had completed questionnaires about their diet.
Participants were assessed as having a healthier diet if they ate more fruits, vegetables, pulses, and wholegrains. Unhealthier diets focused more on sugary foods and drinks, and red and processed meat.
The participants were divided into 5 groups based on the healthiness of their diet.
Those involved in the study were also assessed on the health of their lifestyle, including their weight, exercise levels, and whether they smoked.
The participants were also asked whether they had a relapse of MS symptoms or a gradual worsening of symptoms in the previous 6 months. They were also asked to report their level of disability and how severe their symptoms were, including fatigue, mobility, pain, and depression.
The study found that people in the group with the healthiest diet were 20% less likely to have more severe physical disability than those in the least healthy diet group.
Higher intakes of wholegrains and dairy products were particularly associated with lower disability, while higher overall diet quality was linked with less severe depression.
An overall healthier lifestyle, including better diet, was associated with less severe depression, pain, fatigue, cognitive impairment, and disability, the researchers report.
The authors acknowledge several limitations to their study. They say it is not possible to predict whether a healthy diet can change MS symptoms in the future. Also, participants tended to be older, mainly white, and had been diagnosed with MS for an average of nearly 20 years.
A spokesperson for the MS Trust tells us: "This study provides good evidence that a healthy diet and lifestyle is associated with lower levels of MS disability and symptom severity, although it is not able to demonstrate that a healthy diet causes lower levels of disability.
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