Asthma could be caused by pH imbalance

NEW DELHI, APRIL 2: American researchers have found that the breath of asthmatics is much more acidic than normal, reported the New York T...

NEW DELHI, APRIL 2: American researchers have found that the breath of asthmatics is much more acidic than normal, reported the New York Times. The breath pH — measuring acidity or alkalinity — becomes more acidic during an attack, they found.

Though they could not say what led to the sudden increase in acidity, they did conclude that acidity inflammed lung tissue and played a role in closing down airways. They also found that when patients having attacks were given steroids, their pH balance returned to normal.

It could be that the lungs have evolved a self-defense mechanism against airborne pathogens and could, like other organs, increase their acid content to fight pathogens. The stomach and the kidneys are known to do this, so the lung’s ability to raise or lower airway acidity should not surprise.

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Asthma may thus be a disease in which the lung’s natural defence mechanism — here, it’s ability to produce acid when challenged by a microbe — has gone awry, with the lungs producing too much acid at the wrong time.

This would also explain why asthma attacks increase in smoggy weather. “Smog has high concentration of sulphur dioxide, a strong precipitator of asthma, and forms complex compounds on reacting with other chemicals in the air,” says J N Pande, Head, Department of Medicine, All India Institute of Medical Sciences. One of the compounds produced is sulphuric acid. This excess acid can cause an imbalance in the airway chemistry and force the airways to shut down.

“Chemicals are increasing in the atmosphere, and apart from air pollution and smoking, additives and chemicals in food are aggravating the problem,” says Pande.

Asthma has increased 2-3 per cent in the last decade, and afflicts 4-8 per cent children and 5 per cent of all adults, according to conservative estimates. Rajesh Chawla, Senior Consultant of Respiratory Medicine at Apollo, puts the figure at a higher 10 per cent.

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The pH scale is measured from 0 to 14. While acidic solutions like vinegar fall in the range of 3 to 5, alkaline solutions measure above 7. People without asthma or asthmatics who have the disease under control usually have a breath pH above 7. But the asthmatics who are wheezing have a pH of about 5, found the researchers.

If asthma could be caused by this pH imbalance, non-steroidal treatments could be used to neutralise excess acid and prevent attacks, concluded Dr Benjamin Gaston, an associate professor of pediatric pulmonary medicine at the University of Virginia in American Journal of Respiratory and Critical Care Medicine. Such treatments could be cheap and non-toxic, unlike the steroids currently used.