Multiple sclerosis (a disorder of the central nervous system resulting in symptoms such as weakness, numbness, loss of muscle coordination, problems with vision, speech and bladder control) is believed to occur in people who are genetically predisposed to the disease. However, to develop multiple sclerosis even genetically susceptible individuals need to be exposed to certain factors in their environment such as infection, diet related factors etc. One of the factors, which has been recently investigated, is smoking. A study conducted on 20,000 Norwegians has shown a significant association between smoking and the risk of developing Multiple Sclerosis (MS).
During the study all the participants were clinically examined and given a questionnaire, which enquired about any current/past history of smoking, the age at which they started smoking, as well as if an individual had MS and if so, when exactly were MS symptoms first noted. After reviewing all the questionnaires the researchers concluded that those participants who were currently or formerly smoking were two times more at risk of developing Multiple Sclerosis as compared to those who never smoked. It was observed that it took on an average about 15 years (from the time one started smoking) for symptoms of MS to develop.
Although a few studies have established a link between smoking and Multiple sclerosis, further studies are required to explain the exact mechanism, which is responsible for a possible link between the two. The researchers conclude that although this study does not prove that current or past smoking can aggravate MS in people already having the disease, there is evidence enough to prove that smoking does cause shortness of breath, increase susceptibility to lung infections and predisposition to heart diseases. All these conditions may cause a mild or moderate neurological limitation to develop into a severe disability. Hence, smoking is best avoided as it not only increases the risk for MS but also adds up to the burden of risk of many other diseases such as COPD, asthma, angina, heart attack etc.