According to this study, the number of adults suffering from asthma has more than doubled in the last 2 decades, with steroid prescriptions increasing 6-fold. According to this study:
The main reason for the asthma increase is allergies.
Among people who never smoked the rate of hay fever (a type of allergy) went up from 6% to 20% and the rate of asthma increased from 3% to 8%.
Among smokers, hay fever rose from 5% to 16% and asthma went up from 2% to 5%.
The number of prescriptions for inhaled steroid medications for asthma has increased more than 6 times in the last decade.
British Medical Journal July 8, 2000;321:88-92.
Other reasons of course include all the environmental toxins that we are exposed to, such as solvents, pesticides and heavy metals such as mercury. Vaccinations and unresolved emotional stresses are also likely significant factors in most individuals.
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