Association between multiple sclerosis and dietary patterns based on the traditional concept of food nature: a case-control study in Iran.

INTRODUCTION It remains a matter of debate whether traditional concepts regarding the nature of food affect the development and progression of multiple sclerosis (MS).To date, there are limited studies that have investigated the association between MS and dietary patterns based on the categories of food nature (hot, cold, or balanced) defined in traditional medicine. METHOD This case-control study was conducted from October 2019 to February 2020. In total, 60 patients diagnosed with MS within the preceding 6 months and referred to our neurology outpatient clinic were included in our case group. The control group included 180 patients who were referred to the same center for general or orthopedic surgery. Dietary intake was assessed in both groups through a reliable and valid semi-quantitative food frequency questionnaire. Data were assessed using principal component analysis. RESULTS The mean age of the participants was 44.9 ± 17.33 years. The analysis showed that four food patterns were distinguished (eigenvalue > 1), namely "additives and cold-natured foods", "hot and balanced foods and nuts", "dairy and legumes", and "hot and balanced starches". These food patterns explained 57.8% of the total variance. After adjusting all confounding factors, individuals in the highest quartile and medium quartile of "additives and cold-natured foods" had an elevated MS risk compared with the lowest quartile (OR = 7.21, 95%CI = 2.01-12.38 and OR = 3.37, 95%CI = 1.02-11.35, respectively). Furthermore, individuals in the highest quartile of the "hot and balanced foods and nuts" group were protected against MS compared with its lowest quartile (OR = 0.28, 95%CI = 0.08-0.90). Moreover, a protective effect against MS was seen in the highest quartile of the "hot and balanced starches" group relative to its lowest quartile (OR = 0.34, 95%CI = 0.12-0.98). No significant association was found between "dairy and legumes" and the risk of MS. CONCLUSION This study revealed that dietary patterns based on the traditional concept of food nature might be associated with the risk of developing MS. This represents the first work in this area, so further research is recommended.