Scientists and physicians have noticed that the rates of asthma have been increasing in recent decades.
Several national reports call it an epidemic: a 74 percent increase in self-reported asthma over the past two decades, says the federal Centers for Disease Control and Prevention.
"There's no specific test for asthma," although there are plenty of clues, says Dr. Neil Schachter, a lung specialist at Mount Sinai Medical Center in New York City and author of "Life and Breath," a patient-friendly book about asthma, emphysema, chronic bronchitis and other lung diseases.
"We have much better treatments now, a much better understanding of this disease" than 25 or 30 years ago, Schachter, says.
"We didn't understand then, for example, that this was an inflammatory disease, that it was frequently triggered by allergy and by irritants. We didn't know that if you don't manage it correctly, that it can go on and produce a chronic and sometimes irreversible lung disease," he continued.
Although the long-term effects of some medications aren't known, most doctors now agree that asthma patients should be on long-term inhaled corticosteroids to reduce inflammation, and perhaps a long-acting bronchodilator, to relax smooth airway muscles.
Research into the causes of this striking increase in asthma has led to a number of possible explanations being proposed, but there has yet to be unanimous agreement on the reasons.
A study reported in the American Journal of Respiratory and Critical Care Medicine evaluated a group of patients at two points in time, 30 years apart. The study performed by doctors in Scotland detected a significant increase in symptoms of allergic asthma and levels of antibodies to environmental allergic factors, such as dust mites, pets, and air pollutants over the three decades.
Importantly, the researchers noted that there was an increase in the signs and symptoms of allergy, even in people without a family history of allergy.
The authors conclude that the factors within the environment seem to be contributing to an increased rate of asthma, regardless of a family history of allergy.
There are already known to be genetic (inherited) factors that predispose people to the development of asthma. This new study suggests that factors in our environment are most likely to be the culprits in the rise of allergic disease. Further investigations into the elements of these airborne factors could bring very significant advances into how many allergic conditions including asthma are treated.
The bottom line of this study seems to alter the old saying "you are what you eat" to something like "you are what you breathe."