Asthma and obesity: Linked by high fat diet?

Asthma is one of the most common chronic diseases we face, and one whose prevalence is rising. Most of us know someone suffering from the condition, and most of us are probably familiar with the common list of triggers and risk factors. Obesity is another major health care and public health challenge, encouraged at least in part by a global shift towards eating high fat, high calorie meals. Now Australian researchers are reporting an interesting confluence of factors that may link the two, and potentially adding a more obscure item to the asthma-triggers list. In a small "food challenge" study, the Aussies found that feeding asthma sufferers high fat meals threatened them in two ways: Increasing inflammation in their airways, which could potentially trigger an asthma attack, and inhibiting the effects of the common asthma medication albuterol.

Meanwhile, researchers from the Netherlands report that telemonitoring asthma patients can improve their care. In a small study of 89 patients, half were given monitors that measured exhaled nitric oxide, a measure of how well controlled your asthma is, and access to a web site to document these measurements, and other symptoms. Using these data, doctors could easily and constantly monitor their symptoms and make medication adjustments. Compared to the other half, who received usual treatment, telemonitored patients maintained control of their asthma using fewer doses of steroids.

German researchers, meanwhile, have found that chronic exposure to particulate air pollution responsible for exacerbating asthma and other conditions may also increase blood pressure. After following a cohort of 5,000 people between 2000 and 2003, they found that those exposed to higher levels of fine particulate matter had, on average, higher systolic and diastolic blood pressure than those enjoying cleaner air. Previous research has linked shorter term fluctuations in air quality to short term fluctuations in blood pressure, but this is some of the first evidence showing the potential for a chronic, long term effect.

These findings underscore the importance of using public health approaches to reduce risk factors and underlying causes of ill-health, rather than simply focusing obsessively on health care interventions for specific diseases. In this case, reducing the consumption of high fat foods may reduce not only obesity, and the fleet of diseases that it inspires, but also asthma. Change the diet, reduce many diseases, treat asthma and you control only one disease.

This international patchwork of research is being presented at this years American Thoracic Society meeting, held this year in New Orleans, a city that knows something about environmental and social impacts on health.