Can diet affect the course of your MS?


16 November 2016

The study in brief

This pilot study aimed to test the effect of diet in a group of people with relapsing remitting MS. 61 people took part in a year-long study; 29 continued with their usual diet while 32 followed the McDougall diet, a plant-based diet which is very low in saturated fats.

There was no difference in the number of lesions seen on MRI scans or disability between the two groups, suggesting that diet might not influence the course of MS. People who followed the diet did show improvements in measures of fatigue, lost significantly more weight than the control group and had significantly lower cholesterol levels. People who followed the diet also had higher scores on a questionnaire that measured their quality of life and overall mood.

The small numbers of people in the study and the relatively short duration of the study make it difficult to draw firm conclusions from the results. Improvements in fatigue seen in the diet group may have resulted from weight loss, a finding which has been seen in other studies. The researchers also point out that simply participating in the diet group, with the expectation of benefits, could have contributed to lower fatigue levels.

The study in detail

Background

Many people are interested in the potential to manage their MS through diet. This is a controversial topic and opinions range from denying any benefit to claims that particular diets can effectively cure MS. Several dietary approaches to managing MS have been proposed, usually as a part of a wider programme of lifestyle changes, including Overcoming multiple sclerosis, the Swank diet and the Best Bet diet.

This pilot study aimed to test the McDougall diet, a very low fat vegetarian diet based on starchy vegetables, plus fresh or frozen fruits and other vegetables.

How this study was carried out

61 people with relapsing remitting MS took part in the year-long study; 29 (control group) continued with their usual American diet while 32 (diet group) followed the McDougall diet. This diet is based on starchy plant foods (beans, breads, corn, pastas, potatoes, sweet potatoes, and rice with the addition of fruits and non-starchy vegetables). Meat, fish, eggs, dairy products and vegetable oils (such as corn and olive oil) are prohibited.

At the start of the study, the diet group attended a residential diet training course. The control group had no diet training but did attend an exercise seminar. All participants had clinic visits at the beginning of the study and then at months 1, 3, 6, 9, and 12. Most of the participants in both groups were already taking a disease modifying drug and continued with this throughout the study.

What was found

There was no difference between the two groups in the number of lesions detected on MRI scans, in relapse rate or level of disability measured by EDSS. However, people who followed the study diet showed improvements in measures of fatigue, lost significantly more weight than the control group and had significantly lower cholesterol and fasting insulin levels. People who followed the diet also had higher scores on a questionnaire that measured their quality of life and overall mood.

What does it mean?

There was no difference in MRI or disability between the two groups, suggesting that diet might not influence the course of MS, but the small numbers of people in the study and the relatively short duration of the study make it difficult to draw firm conclusions from the results.

The improvement in fatigue levels seen in the diet group was associated with weight loss, a finding which has been reported in other studies. The researchers point out that simply participating in the diet group, with the expectation of benefits, could have contributed to this effect. This highlights one of the key problems with carrying out research into dietary modifications; that it is impossible to prevent participants from knowing which group they have been assigned to, which then introduces a potential bias in the results.

Yadav V, et al
Low-fat, plant-based diet in multiple sclerosis: A randomized controlled trial
Multiple Sclerosis and Related Disorders 2016; 9: 80-90
Abstract
Read the full text of this paper

More about diet

Our healthy eating page looks at the elements of a healthy diet and summarises and reviews evidence about diet in MS.

More recently, research has suggested that low levels of vitamin D are associated with an increased risk of getting MS. In established MS, low levels of vitamin D have been associated with relapses and increased disability. At the moment, there is limited evidence to show that taking vitamin D supplements will reduce the severity of MS.  Studies are underway to evaluate vitamin D supplementation. Some MS neurologists recommend that people with MS and their family members take 4000-5000 IU vitamin D per day, some propose lower doses of between 800-3000 IU/day, while others advise waiting for more evidence of effectiveness from clinical trials before taking supplements.

While research into diet and multiple sclerosis has been limited, there has been considerable research into a healthy diet for other conditions. Following a healthy, balanced diet which is low in fat and includes plenty of fruit and vegetables is important for maintaining general health and reducing the risk of developing other conditions such as heart disease, stroke and diabetes. Your GP or MS nurse can give you advice on how to achieve and maintain a healthy weight through diet and exercise.

NHS Choices has some excellent resources on living well.

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