Geomagnetic disturbances may be environmental risk factor for multiple sclerosis: an ecological study of 111 locations in 24 countries

Abstract

BackgroundWe noticed that a hypothesis based on the effect of geomagnetic disturbances (GMD) has the ability to explain special features of multiple sclerosis (MS). Areas around geomagnetic 60 degree latitude (GM60L) experience the greatest amount of GMD. The easiest way to evaluate our hypothesis was to test the association of MS prevalence (MSP) with angular distance to geomagnetic 60 degree latitude (AMAG60) and compare it with the known association of MS with geographical latitude (GL). We did the same with angular distance to geographic 60 degree latitude (AGRAPH60) as a control.MethodsEnglish written papers with MSP keywords, done in Europe (EUR), North America (NA) or Australasia (AUS) were retrieved from the PubMed. Geomagnetic coordinates were determined for each location and AMAG60 was calculated as absolute value of numerical difference between its geomagnetic latitude from GM60L. By an ecological study with using meta-regression analyses, the relationship of MSP with GL, AMAG60 and AGRAPH60 were evaluated separately. MSP data were weighted by square root of number of prevalent cases. Models were compared by their adjusted R square (AR2) and standard error of estimate (SEE).Results111 MSP data were entered in the study. In each continent, AMAG60 had the best correlation with MSP, the largest AR2 (0.47, 0.42 and 0.84 for EUR, NA and AUS, respectively) and the least SEE. Merging both hemispheres data, AMAG60 explained 56% of MSP variations with the least SEE (R = 0.75, AR2 = 0.56, SEE = 57), while GL explained 17% (R = 0.41, AR2 = 0.17, SEE = 78.5) and AGRAPH60 explained 12% of that variations with the highest SEE (R = 0.35, AR2 = 0.12, SEE = 80.5).ConclusionsOur results confirmed that AMAG60 is the best describer of MSP variations and has the strongest association with MSP distribution. They clarified that the well-known latitudinal gradient of MSP may be actually a gradient related to GM60L. Moreover, the location of GM60L can elucidate why MSP has parabolic and linear gradient in the north and south hemisphere, respectively. This preliminary evaluation supported that GMD can be the mysterious environmental risk factor for MS. We believe that this hypothesis deserves to be considered for further validation studies.

Is a hypothetical melanoma-like neuromelanin the underlying factor essential for the aetiopathogenesis and clinical manifestations of multiple sclerosis?

“…Moreover, the concept sheds light, in principle, on a number of epidemiological observations on factors possibly involved in the aetiology of MS, in particular EBV infection, the HLA system, geomagnetic disturbances/cosmic radiation, vitamin D levels, and smoking, as well as several others listed in Table 1. The possible involvement of cosmic radiation [77,78] is an aspect in which interest has been revived [1] and it has been investigated recently in a mouse model of Alzheimer’s disease [79]. Although definitive answers cannot be given to any of the many specific questions raised on possible relations to the hypothetical MLN, it should be noted that the concept as a whole is unique amongst the hypotheses on MS in not contradicting the birth cohort trends [2].…”

“…The recent paper by Sajedi and Abdollahi in this journal [1] on geomagnetic disturbances as a risk factor for multiple sclerosis (MS) emphasises the complexity of the pathogenesis of this disease but also encourages a search for an underlying factor that could be affected by such disturbances and other risk factors. A recent broad-ranging epidemiologic study also focuses attention on the aetiology of multiple sclerosis and facilitates a reappraisal of the putative risk factors [2].…”

“…An oscillating process of oxidative charging and discharging of neuromelanin appears to be promoted by the combination of two equally important environmental effects, charging triggered by geomagnetic disturbances/cosmic radiation [1] and discharging by reduction equivalents that must be generated by the cells in a vitamin D-dependent manner [35] ●●●.…”

“…The possible importance of geomagnetic disturbances/cosmic radiation is supported by a recent meta-analysis that showed a significantly closer association of MS to 60° magnetic latitude as compared with 60° geographic latitude [1] ●●. One consequence of this important study is that cosmic radiation on Earth’s surface, although of low intensity (about 0.1 r/year) cannot be described as biologically completely harmless.…”

How can proteomics elucidate the complexity of multiple sclerosis?

“…sunlight exposure, diet, infections, and lifestyle) have been associated with multiple sclerosis risk to some extent. However, none of these factors alone have shown a high odds ratio [2,12]. Thus, genetic and epidemiological studies have indicated that the disease must be a result of a complex genetic predisposition combined with an environmental trigger [7,13,14].…”