An intermittent fasting (IF) diet may lead to immune and metabolic alterations that ease multiple sclerosis (MS) symptoms and improve quality of life, a recent review of published studies suggests.

While evidence from these few small clinical trials indicate an IF diet might help manage “this intricate neuroimmune disorder,” larger clinical trials “are urgently needed” to better establish the relationship, said researchers in “The effects of intermittent fasting for patients with multiple sclerosis (MS): a systematic review,” which was published in Frontiers in Nutrition.

Various dietary practices have emerged as possible interventions for reducing inflammation and easing MS symptoms. In IF, periods of caloric restriction are interspersed with periods of normal calorie intake.

Preclinical research has supported its possible benefits. For example, such a diet was found to ease disease severity and reduce inflammation in the early stages of a mouse model of MS.

Building on those preclinical findings, a number of small clinical trials investigated the possible benefits of IF protocols in MS patients, but each differed in terms of the diet protocol and patient groups.

Different regimens of intermittent fasting

 Here, researchers reviewed previously published clinical studies related to IF in MS to “elucidate the potential therapeutic efficacy and implications of IF strategies in the comprehensive management of MS,” and identified four randomized controlled clinical trials and one pilot study. Each involved 12 to 70 participants, with a mean age range of 37.4 to 46. The participants practiced IF anywhere from 15 days (about two weeks) to 56 days (about two months).

The studies used various IF regimens, including the 5:2, time-restricted eating (TRE), and alternate-day fasting (ADF) approaches. With 5:2, calories are restricted for two nonconsecutive days of the week but remain normal the other five. TRE involves consuming calories during a set period of the day and limiting them outside that period, while ADF entails alternating daily between normal calorie intake and calorie restriction.

Only one of the five studies investigated ADF in relapsing-remitting multiple sclerosis (RRMS) patients. Findings from the pilot randomized clinical trial found an ADF diet led to protective metabolic alterations in the blood and certain microbe changes in the gastrointestinal tract. It was also associated with reductions in immune cell populations that are implicated in MS.

Another research group found that both daily calorie restriction and a 5:2 IF diet led to weight loss and improvements in emotional health among RRMS patients. In a follow-up study, IF was associated with significant changes in immune cell subsets that weren’t observed with daily calorie restriction.

One publication noted a significant challenge with implementing calorie restricted diets in MS: patient adherence. The analysis indicated that a TRE diet might be the most user-friendly approach.

Consistently, the final study found TRE was feasible and acceptable for adult RRMS patients who reported reductions in fatigue and improvements in sleep and overall well-being with the diet.

“The cumulative evidence from these studies suggests that IF protocols could potentially serve as an effective dietary strategy for managing symptoms and improving the quality of life in individuals afflicted with MS,” the researchers wrote. “The landscape of dietary interventions for MS—each with its distinct merits and challenges—requires careful consideration, particularly regarding the sustainability of long-term adherence.”

Still, conclusions can’t be drawn from these few small studies, the researchers said. Large, well-controlled trials are needed to establish the possible benefits of various IF regimens for MS.

“Expanding the breadth of research in this area will not only affirm the findings from preliminary studies but also enhance our understanding of the intricate mechanisms by which dietary interventions may influence disease trajectories in autoimmune conditions such as MS,” they wrote. “There is a pressing need for large-scale clinical trials designed to rigorously investigate the therapeutic potential and mechanistic underpinnings of IF in the context of MS.”