Fruits and vegetables intake may be associated with a reduced odds of multiple sclerosis: a systematic review and dose-response meta-analysis of observational studies.

INTRODUCTION: Multiple sclerosis (MS) is an immune-mediated condition of the central nervous system (CNS). Intake of fruits and vegetables high in vitamins, minerals, fiber, and active molecules contributes to the body's overall health, immunity, and physiological function. This study sought to review the literature and investigate the relationship between fruits and vegetables consumption and MS odds.

METHODS: In the current systematic review and meta-analysis, a systematic search of original databases from inception to 21 Dec 2022 was conducted based on the PRISMA 2020 statement. Human observational studies examining the association between fruits or vegetables consumption and MS prevalence were included if they reported and provided effect size with 95% confidence intervals (CIs).

RESULTS: The systematic review and meta-analysis included eight studies. Random effect model showed the protective effect of fruits ( I 2  = 81.0%, P for heterogeneity < 0.001; pooled OR = 0.52, 95%CI = 0.27, 0.97, P -value = 0.042) and vegetables consumption ( I 2  = 73.5%, P for heterogeneity = 0.002; pooled OR = 0.61, 95%CI = 0.38, 1.00, P -value = 0.050) on MS odds. According to a linear dose-response meta-analysis of four case-control studies, an increase of 100 grams of fruits per day reduced the odds of MS by 9% ( I 2  = 0.0%, P for heterogeneity = 0.77; pooled OR = 0.91, 95%CI = 0.83, 0.99, P -value = 0.021).

CONCLUSION: Consumption of fruits and vegetables may be associated with a potential protective effect against MS. However, further confirmation is required through prospective longitudinal studies and randomized clinical trials.