High-quality diets with large intakes of fruits, vegetables, and whole grains and low intakes of sugar and red meat are associated with lower levels of
disability in people with multiple sclerosis (MS), a new large registry study shows.
In addition, a generally healthy lifestyle was also linked to lower prevalence of severe depression, pain, fatigue, and cognitive problems.
"As diet and other lifestyle factors are modifiable, they offer a promising, safe
avenue to ameliorate MS-associated symptoms and influence
disease course," investigators, led by Kathryn C. Fitzgerald, ScD, Johns Hopkins School of Medicine, Baltimore, Maryland, write.
The study was published online December 6 in Neurology.
A First Look
"There are pretty limited data on diet and MS, and this is one of the largest studies to have looked at this issue," Dr Fitzgerald told Medscape Medical News.
"However, because our study is cross-sectional — it just investigated the association at one time only — it has to be considered as a first look. I wouldn't say our results are enough to make definite clinical recommendations for MS patients, but they are a good starting point for further research."
"We can't know for sure if the better diet is having a direct effect on MS itself or whether just eating healthily is generally good for you and so has an indirect positive effect. But it could affect oxidative stress and other basic processes involved in the disease.
"But we know that people with MS have an increased risk of cardiometabolic comorbidities, such as diabetes and high cholesterol, so a high-quality diet will help reduce those conditions. And we all know that eating a high-quality diet has many health benefits, so what is there to lose from doing this?"
The current study was part of the North American Research Committee on MS (NARCOMS) registry. For the study, conducted in 2015, 11,000 active participants were sent a dietary questionnaire and were asked to evaluate MS symptoms and disability levels using the Patient-Determined Disease Steps scoring system, developed and validated by the NARCOMS group.
A diet quality score was constructed for each individual based on intake of fruits, vegetables, legumes, whole grains, added sugars, and red/processed meats, with higher scores denoting a healthier diet.
Associations between diet quality score and MS symptoms and disability levels were estimated by using proportional odds models, adjusting for age, sex, income, body mass index, smoking status, and disease duration.
Results showed that 6989 patients responded to the survey and provided dietary information. Participants with diet quality scores in the highest quintile had 20% lower levels of "more severe disability" than those in the lowest quintile of diet quality scores: proportional odds ratio (OR), 0.80 (95% confidence interval [CI], 0.69 - 0.93). Patients in the highest dietary score quintile also had lower depression scores (OR, 0.82; 95% CI, 0.70 - 0.97). But diet quality was not associated with severity of fatigue, pain, or cognitive symptoms.
Because poor dietary quality tends to correlate with other unhealthy lifestyle characteristics, the researchers assessed whether a similar association existed in people with MS using indicators of a composite healthy lifestyle, defined as maintaining a healthy weight (body mass index < 25 kg/m2), routine physical activity, no smoking, and having a better than average diet (above the median diet quality score).
Results of this analysis suggest that individuals who adhered to a composite healthy lifestyle were at substantially lower odds of severe depression (OR, 0.53), pain (OR, 0.56), fatigue (OR, 0.69), and cognitive symptoms (OR, 0.66) after adjustment for disease duration, disability level, age, and sex. A composite healthy lifestyle was also associated with lower odds of severe disability (OR, 0.45).
The researchers caution that causal inferences cannot be made from this study because poor physical or mental health may lead to poorer diet quality, food choices, or other lifestyle factors.
"Longitudinal studies are needed to gain a better understanding of the directionality of the association between diet, a composite healthy lifestyle, and disease outcomes," they add.
Food for Thought
Commenting on the study for Medscape Medical News, Jeffrey Cohen, Cleveland Clinic, Ohio, said there is increasing recognition of the role of wellness and general health issues in MS care.
"We do counsel patients about diet, although the data on which to base those recommendations are currently rather limited. This study provides valuable data supporting the importance of diet. Further studies are needed to identify the specific aspects of diet to emphasize," he said.
In an accompanying editorial, James F. Sumowski, PhD, Icahn School of Medicine at Mount Sinai, New York City, and coauthors write that "the field of diet in MS has served up courses of a priori opinions garnished with anecdotes and small samples, to which Fitzgerald et al. add substantive and robust empirical data. This sets the table for subsequent work on mechanisms of action and causal relationships."
They note that the next steps are to perform randomized controlled trials of diet to yield causal evidence for dietary interventions and to identify specific dietary factors and mechanisms of action driving protective effects.
But until the results of such trials are available, "encouraging a healthy lifestyle (healthy eating, a normal weight, routine physical activity or exercise, and avoiding smoking) should be a fundamental message we give to all newly diagnosed patients with MS."
NARCOMS is supported in part by the Consortium of Multiple Sclerosis Centers (CMSC) and the Foundation of the CMSC. Dr Fitzgerald receives research funding from the CMSC.
Neurology. Published online December 6, 2017. Abstract, Editorial
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Cite this: High-quality Diet, Healthy Lifestyle May Reduce MS Disability - Medscape - Dec 08, 2017.