If you overdo the calories and lay off the exercise, it isn’t just your belly that will become loaded with fatty tissue, the airways deep in your lungs could also become jam-packed with fat cells.
Scientists from the University of Western Australia (UWA) in Perth have found evidence that fat can gather in the lung tissue of overweight and obese people for the first time.
It’s pretty well known that overweight people are more likely to wheeze and have trouble breathing, however, it was thought that this was due to excess fat applying pressure on the chest. As the new study shows, a whole other mechanism could be at play. In turn, this could also shed light on the understudied link between obesity and asthma.
A new study published in the European Respiratory Journal carried out a post mortem on the lungs of 52 deceased people – 16 had died of asthma, 21 had asthma but died of unrelated causes, and 15 had never experienced any symptoms of asthma. Researchers studied the samples under a microscope and quantified the levels of fatty adipose tissue present in the walls of the lungs’ airways. They then compared this to each person's body mass index (BMI).
To their surprise, the researchers found a direct correlation between BMI and levels of fat in the lungs: the more overweight a person was, the more adipose cells could be found in the walls of their airways. They also found that an increase in fat alters the normal structure of the airways and leads to inflammation in the lungs, which could lead to serious health problems.
Fat, scientifically known as adipose tissue, is a bright yellowy-orange bobbly tissue composed of thousands of adipocytes, or fat cells. Its main job is to store energy for later use, but it also plays a role in insulating the body and providing protective padding. As you can imagine, having this inside your airways can make it harder to breathe and perhaps explains why asthma is often associated with being overweight.
“We’ve found that excess fat accumulates in the airway walls where it takes up space and seems to increase inflammation within the lungs. 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,” Associate Professor Peter Noble, study co-author from UWA’s School of Human Sciences, explained in a statement.
It could also offer some practical help for people battling with asthma. Although it has yet to be proved, these findings suggest that asthma could be treated or even reversed with weight loss.
"We need to investigate this finding in more detail and particularly whether this phenomenon can be reversed with weight loss. In the meantime, we should support asthma patients to help them achieve or maintain a healthy weight," Professor Thierry Troosters, president of the European Respiratory Society, who was not directly involved in the study, commented on the findings.