Flavonoid rich dark cocoa may improve fatigue in people with multiple sclerosis, yet has no effect on glycaemic response: an exploratory trial

CONTEXT: Current research suggests that dark cocoa may reduce fatigue; however, the effect on fatigue in people with MS (pwMS) has never been established. The objective of this feasibility study was to explore the acute effect of high flavonoid cocoa on measures of fatigue and glycaemic response. METHODS: This was a randomised crossover participant blind exploratory study in 12 participants (2 male and 10 female) with MS-related fatigue (>4 on the Fatigue Severity Scale; FSS). After fasting overnight, participants consumed the high flavonoid cocoa drink (350 mg gallic acid equivalents {GAE}/g) or a low flavonoid cocoa control (120 mg GAE/g), consuming the alternative drink on the next visit. Fatigue was self-reported on a 100 mm visual analogue scale at 30-min time intervals for 2 h post cocoa consumption and every 2 h for the rest of the day. Fatigability was monitored using a 6 min walk test (6MWT) at the end of the visit (2 h), and activity monitors worn for 24 h commencing at 12 noon on the day of testing. The feasibility of performing the trial including outcome measures was documented. RESULTS: A moderate effect was found in self-reported fatigue throughout the day in favour of the high flavonoid group (Cohen's d 0.32, 95% non-central t CI -0.57 to 1.20). Fatigability measures did not change. Participants consumed and enjoyed the cocoa, all participants completed the study and outcome measures were accepted. CONCLUSION: The results of this study support further trials to investigate the feasibility and efficacy of pure cocoa as a dietary supplement for fatigue in pwMS.