Expert Review of Neurotherapeutics
March 2010, Vol. 10, No. 3, Pages 421-440 , DOI 10.1586/ern.10.7
Environmental risk factors in multiple sclerosis
The etiology of multiple sclerosis is, at present, not definitely known, but genetic and environmental
factors play a role in its causation. Environmental causes have a predominant impact. Epidemiologic
research has contributed considerably to the identification of external risk factors in this multifactorial
setting, but methodological constraints still play a major part. Viral and other microbial agents have
drawn much attention, although none of them is a necessary condition for the disease. This is true
also for the Epstein–Barr virus, for which most data, including prospective data, supports a role in
the majority of multiple sclerosis patients. In parallel, the hypothesis is still attractive in that it is not
the virus per se, but rather more the age when it infects the human being that is the crucial matter.
Other risk factors, such as tobacco smoking and vitamin D deficiency, which have immunomodulating
properties, may also play some role, although the latter is not compatible with all data of the
descriptive epidmiology of multiple sclerosis. Diet might be of considerable importance, all the more
since multiple sclerosis can be ecologically attributed to a certain food patterns and is inversely
associated with others (e.g., the ‘Mediterranean diet’). The hypothesis that the preservation of meat
by nitrite and wood smoke plays a role, and the protective influence of a fish and, possibly, a vegetable
diet, are supported by some studies, but methodological constraints limit, at present, definite conclusions.
A new avenue is the search for an interaction between genetic and environmental causes, and also
between several environmental factors that might lead to new approaches for prevention and, perhaps,
for the treatment of multiple sclerosis.
Sausage Preservation Methods and the Prevalence of Multiple Sclerosis: An Ecological Study
http://www.informaworld.com/smpp/conten ... 053&db=all
Sausage preservation methods (smoking vs. drying), as classified by Hippisley Coxe and Hippisley Coxe
(1986), were compared with the prevalence of multiple sclerosis (MS) in 26 countries. Meat, pork, and
animal fat consumption, divided by food energy intake, were taken as covariates. In logistic regression
smoke preservation, meat consumption and animal fat consumption showed a significant association
with MS in univariate analysis. In multiple logistic regression, smoke preservation was associated with
MS independently from meat and pork consumption, whereas animal fat contributed with borderline
significance. The data suggest an association between sausage preservation by smoking and MS.
A possible causal link should be studied further by individual-based epidemiological approaches.