Is There Fat in Your Lungs?

BBC News just published an article which reported that fatty tissue has been found in the lungs of overweight and obese people for the first time. The information came from a group of Australian researchers who analyzed lung samples taken from 52 people. They found that the amount of fat increased in line with body mass index (BMI).

The researchers reported that their findings could possibly explain why your risk of asthma increases if you're overweight or obese. Lung experts chimed in and said how interesting it would be to see if weight loss could reverse the effect.

The study was published in the European Respiratory Journal. During the study, scientists examined post-mortem samples of lung donated for research. Fifteen of the fifty-two samples had had no reported asthma, twenty-one had asthma but died of other causes, and sixteen died of the condition.

The Australian scientists used dyes to help analyze the 1,400 airways from the lung samples under the microscope. Not only did the researchers find adipose (fatty) tissue in the walls of airways, but more was found in people with a higher body mass index.

The scientists also discovered that the fat altered the normal structure of the airways. This led to inflammation in the lung and could be the reason obese and overweight people are more at risk of asthma. Dr. Peter Noble, an associate professor at the University of Western Australia, in Perth who worked on the study, said: "Being overweight or obese has already been linked to having asthma or having worse asthma symptoms."

Researchers have suggested that the link might be explained by the direct pressure of excess weight on the lungs or by a general increase in inflammation created by excess weight. He said that their study, however, suggests another mechanism is at play.

"We've found that excess fat accumulates in the airway walls, where it takes up space and seems to increase inflammation within the lungs," Dr. Noble said. "We think this is causing a thickening of the airways that limits the flow of air in and out of the lungs and that could at least partly explain an increase in asthma symptoms."

Professor Thierry Troosters, president of the European Respiratory Society, said: "This is an important finding on the relationship between body weight and respiratory disease because it shows how being overweight or obese might be making symptoms worse for people with asthma. This goes beyond the simple observation that patients with obesity need to breathe more with activity and exercise. The observation points at true airway changes that are associated with obesity."

Thierry Troosters also added that more research needs to be done to determine whether losing weight can help remove fatty tissue that has already built up in the lungs. Thierry Trooster concluded by saying that asthma patients need to be helped to achieve healthy weights. This study is the first to show that bodyweight impacts the structure of the airways in the lungs said Dr. Elizabeth Sapey, chair of the science committee at the British Thoracic Society.

"Given the increasing incidence of obesity nationally and across the globe, the study could be of major importance in helping us understand why asthma remains a major health issue and identify new ways to improve asthma treatment," she said. "It is only a small study though, and we need to assess this in larger groups of patients and in other lung diseases."