Dietary Intake of Sodium and Other Minerals and the Risk of Multiple Sclerosis (S37.001)

Abstract

Background: Higher dietary sodium intake has been associated with more severe disease activity both in experimental autoimmune encephalomyelitis (EAE) and in patients with multiple sclerosis (MS). However, the role of sodium and other minerals as risk factors of MS is unclear. Objective: To investigate the association between dietary intake of sodium, potassium, magnesium, calcium, phosphorus, iron and the risk of MS. Methods: We prospectively assessed the intake of the different minerals from diet and supplements by a validated food frequency questionnaire (FFQ) administered every four years to 81 757 nurses in the Nurses’ Health Study (NHS) (1984-2004), and to 95 452 in the Nurses’ Health Study II (NHSII) (1991-2009). In both cohorts combined we confirmed 479 new MS cases during follow-up. The risk of developing MS was analysed using Cox proportional hazard models and reported as hazard ratios (HR) and 95[percnt] confidence intervals (CI). The analyses were adjusted for age, latitude of residence at age 15, ethnic background, body mass index at age 18, supplemental vitamin D intake, cigarette smoking and total energy intake. Subsequently, the results in both cohorts were pooled using fixed effects models. Results: Higher dietary intake of sodium at baseline was not associated with MS risk (highest [median 2.2 g/d NHS; 2.6 g/d NHSII] vs. lowest [median 1.4 g/d NHS; 1.7 g/d NHSII] quintile: HRpooled=0.95, 95[percnt] CI: 0.72-1.27, p for trend=0.84). Nor was the intake of potassium (p trend=0.38), magnesium (0.12), calcium (0.21), phosphorus (0.99) and iron (0.81) associated with the risk of developing the disease. The analyses of the cumulative intake of these minerals (i.e. average intake from all FFQs up to the time of MS onset) yielded similar results. Conclusions: Our findings suggest that neither higher dietary sodium intake nor intake of the other investigated minerals is related to the risk of developing MS.

Disclosure: Dr. Cortese has nothing to disclose. Dr. Chitnis has received personal compensation for activities with Novartis and Biogen. Dr. Chitnis has received research support from Merck-Serono and Novartis Pharmaceuticals. Dr. Ascherio has received personal compensation for activities with Almirall, Bayer HealthCareRoche, Sanofi-Aventis, and Serono. Dr. Ascherio has received research support from the NIH and NMSS. Dr. Munger has nothing to disclose.