New research from Oregon Health & Science University suggests that people with multiple sclerosis, or MS, could benefit from a low-fat diet to improve the fatigue that’s a debilitating, and often-underappreciated, symptom of the condition.

The study, published online Wednesday in the Multiple Sclerosis Journal, is the latest in a line of OHSU research dating back a decade testing the principle that diet matters, especially for people with MS.

“Fatigue is very disabling for these patients,” said principal investigator and senior author Vijayshree Yadav, M.D., professor of neurology in the OHSU School of Medicine and director of the OHSU Multiple Sclerosis Center. “There is no FDA-approved drug for fatigue, but we know that fatigue greatly affects their quality of life.”

In the new study, researchers conducted a randomized controlled trial in which 39 people with MS who experienced fatigue were divided into two groups: 19 people were placed in the control group and received diet training at the completion of the study after 16 weeks. The other 20 received nutrition counseling from dieticians and then adhered to a low-fat diet, which was confirmed through routine blood sampling revealing clear signals of reduced caloric intake.

“You cannot really fudge the biomarkers,” Yadav said.

In contrast to a 2016 study that tested a purely plant-based diet, the new study was modified to include meat while still remaining low-fat. Exercise was not part of the program, meaning the study solely focused on diet as an intervention.

Compared with the control group, the active group of participants revealed significant improvement in fatigue, which was gauged through the Modified Fatigue Impact Scale. Every four weeks, participants answered standardized questions measuring aspects such as their ability to pay attention, concentrate and to carry out routine physical activities.

“The results reinforced what we had seen before,” Yadav said. “A low-fat diet can truly make a difference in a patient’s fatigue level, even without going so far as to make it a vegan diet.”