Environmental risk factors and multiple sclerosis: an umbrella review of systematic reviews and meta-analyses

Environmental risk factors and Parkinson's disease: An umbrella review of meta-analyses

“…5 The F o r P e e r R e v i e w 5 methods of the umbrella review are standardized and follow exactly the same principles as a previous umbrella review on risk factors for multiple sclerosis. 6 We systematically searched PubMed from inception to April 16, 2015 to identify systematic reviews and meta-analyses of observational studies examining associations of environmental (non-genetic) factors and biomarkers with PD. The search strategy used the keywords Parkinson* AND ("systematic review" OR meta-analysis).…”

“…From each eligible article, we recorded the first author, journal, year of publication, the examined risk factors and the number of studies considered. If a quantitative synthesis was done, we also extracted the study-specific relative risk estimates (mean difference, risk ratio, odds ratio, hazard ratio or incident risk ratio) along with the F o r P e e r R e v i e w 6 corresponding CI and the number of cases and controls in each study for each risk factor. Furthermore, we recorded the study design of individual studies.…”

“…Some of the caveats, pertaining to the interpretation of tests for statistical bias and the potentially effect inflation even in the largest studies, are applicable to all umbrella reviews of risk factors, as we have discussed on a previous umbrella review about risk factors for multiple sclerosis. 6 We did not appraise the quality of the individual component primary studies, because this was beyond the scope of this umbrella review. This was the aim of the original systematic reviews and meta-analyses, which should include an assessment of study quality and whether the study should be included in the quantitative calculations.…”

Aetiology: Neighbourhood watch

“…These meta-analyses have investigated infections, vaccinations, other diseases, surgery, accidents and exposure to toxins. Tzoulaki's team has conducted a review of these meta-analyses 9 . "They looked at every trend or player in these environmental factors, " says Røsjø, who was not involved in the review, which he calls the "pinnacle" study of these factors.…”

Western lifestyle and immunopathology of multiple sclerosis

“…The industrial revolution and the contemporary age in Western countries gave rise to the fast‐food industry and widespread consumption of excessive salt, refined vegetable oils, and sugars and also led to reduced physical activity, exposure to artificial light at atypical biological times, and insufficient and poor‐quality sleep. The influence of other environmental factors, such as Epstein–Barr infection, vitamin D levels, smoking, obesity, and geographical location, has already been extensively reviewed 3, 4, 5. Here, we mainly focus on how Western diet and sleep‐circadian disruption may contribute to our understanding of MS etiology.…”