Anyone old enough to have watched the Marathon Man starring Dustbin Hoffman will remember these words as the Evil Dentist Szell drilled holes into the teeth as a bit of torture to get info from the hero of the film. I didnt have anaesthetic for my fillings until I was eighteen but have loads before then and remember the drill very vividly. The drilled hole was filled historically with amalgam fillings, which are mercury based. Do they affect the development of MS. Apparently but the risk for people with 6 or more p
Guo J, Olsson T, Alfredsson L, Hedström AK. Dental-amalgam exposure and the risk and progression of multiple sclerosis. Int J Epidemiol. 2026 Apr 17;55(3):dyag059.
Background: Concerns about the neurotoxic potential of dental amalgam in multiple sclerosis (MS) persists but its impact on disease risk and progression remains unclear.
Methods: We used data from a Swedish population-based case-control study (2386 cases, 4849 controls) to investigate the association between dental amalgam exposure and MS risk. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated….and interaction with smoking was evaluated. Relapsing-onset MS cases born between 1965 and 1985 (n = 1191) were followed longitudinally by using clinical data from the Swedish MS registry. The time to confirmed disability worsening (CDW) and Expanded Disability Status Scale (EDSS) 3 and 4 were assessed by using Cox regression; EDSS trajectories were analysed by using linear mixed-effects models.
Results: Amalgam exposure was associated with increased MS risk in a dose-dependent manner (OR for trend 1.14, 95% CI 1.08-1.20). A significant interaction with smoking was observed (attributable proportion due to interaction 0.25, 95% CI 0.10-0.40). In the longitudinal cohort, those with at least six fillings had increased risk of CDW [hazard ratio (HR) 1.35, 95% CI 1.07-1.71] and progression to EDSS 3 (HR 1.48, 95% CI 1.07-2.05) and EDSS 4 (1.68, 95% CI 1.01-2.83). Associations were stronger among current smokers, those diagnosed after age 40 years, and individuals on low-efficacy therapies. The EDSS trajectories also showed faster progression in the high-exposure group (P = .044).
Conclusion: Dental amalgam exposure may be associated with both increased risk of MS and faster disability progression. Findings support a potential synergistic effect with smoking and raise the hypothesis that mercury may contribute to MS-related neurodegeneration.
what’s the next risk factor?
Source: multiple-sclerosis-research.org