Healthy diet, lifestyle tied to less disability in MS

Last Updated: 2017-12-12

By Marilynn Larkin

NEW YORK (Reuters Health) - An active, healthy lifestyle and a diet emphasizing fruits, vegetables, legumes, and whole grains are associated with lower levels of disability in people with multiple sclerosis (MS), researchers say.

Dr. Kathryn Fitzgerald of Johns Hopkins Medical Institutions in Baltimore told Reuters Health, "Previous studies have shown that people with MS are at an increased risk of several cardio-metabolic comorbidities, such as hypertension and high cholesterol, and that having these comorbid conditions may adversely affect MS outcomes."

"In people without MS, a multitude of studies show that eating a healthy diet lowers risk of these comorbidities," she said by email. "So, it's possible that a healthy diet may impact MS disability through its beneficial effects on cardio-metabolic risk."

"In addition," she observed, "it's possible that diet can also alter the levels of oxidative stress, mitochondrial function, or the composition of the gut microbiome, which are hypothesized biological mechanisms that have been linked with MS."

Dr. Fitzgerald and colleagues used data from MS registry participants who completed a dietary questionnaire to construct a diet-quality score based on intake of fruits, vegetables and legumes, whole grains, added sugars, and red/processed meat. Higher scores denoted healthier diets.

The team assessed the association between diet quality and disability status using Patient-Determined Disease Steps (PDDS) and symptom severity, with adjustment for age, sex, body-mass index, smoking status, disease duration and income.

They also assessed the association between disability status and composite healthy lifestyle, defined as "one where an individual maintains a healthy weight (BMI <25), routinely engages in physical activity, abstains from smoking, and consumes a better than average diet (> median diet quality score)."

As reported in Neurology, online December 6, close to 7,000 individuals (mean age, 60; 92% white) participated in the 2015 survey. Overall diet-quality scores averaged 11.9 on a 20-point scale. Individuals with higher scores tended to be older, had higher income levels, were less likely to be smokers or overweight, and were more likely to participate in physical activity. Diet-quality score did not vary across clinical MS characteristics.

Participants with diet-quality scores in the highest quintile had lower levels of disability, as measured on the PDDS, and lower depression scores. However, diet quality was not associated with severity of fatigue, pain, cognitive symptoms or symptom severity.

In individual food group analyses, participants in the top quintile for whole grains and total dairy intake were at lower odds of severe versus mild disability than those in the bottom quintile of each food group. Other dietary components were not associated with disability status.

Respondents who reported a composite healthy lifestyle had significantly lower odds ratios (ORs) for severe fatigue (0.69), severe depression (0.53), pain (0.56) or cognitive impairment (0.67), after adjustment for disease duration, PDDS scores, age and sex.

A composite healthy lifestyle also was associated with significantly lower odds of severe versus mild disability (OR, 0.45).

Dr. Fitzgerald noted, "Because of the design of the study, we can't determine if having a healthy diet impacts risk of future disability or how exactly diet could impact MS - i.e., the mechanism through which this occurs - only that there appears to be an association."

Dr. James Sumowski of The Mount Sinai Hospital in New York City, coauthor of a related editorial, said by email, "There is a lot to cover in a typical visit with an MS clinician, and diet may or may not come up during the typical busy session."

"Fitzgerald and colleagues provide the strongest evidence to date that a healthy diet is important for avoiding disability in MS, which merits a change in how diet is addressed clinically - encouraging a move from (a) occasional mention of diet to (b) active patient education, goal-setting, and monitoring of diet," he told Reuters Health.

"This epidemiological study . . . lays the scientific groundwork for critical subsequent studies aiming to delve more deeply into the biological mechanisms underlying this effect, and more-specific recommendations about specific dietary patterns," he observed.

"Clinical trial research on diet is challenging to conduct," Dr. Sumowski acknowledged, "but will provide the highest level of evidence for dietary effects."

SOURCES: http://bit.ly/2C7cb6e and http://bit.ly/2iTjOow

Neurology 2017.