Scientists discovered that fat could find its way to the lungs, contributing to the hypothesis that fat deposits in the lungs can cause blocked airways, and eventually, asthma.
In the research published in the European Respiratory Journal, it details that scientists used materials collected from lung tissue samples from 52 deceased people. The 52 subjects were divided into two groups — 15 (without asthma) and 21 (with asthma) — those who died due to other diseases and those who died due to asthma.
With the help of dyes, researchers were able to analyze almost 1,400 airway structure samples, and determine, that adipose cells or fat have deposited themselves in the deceased person’s airways.
It’s the first time fatty deposits were spotted in the lungs, although they do appear in other organs besides the heart — including the liver. However, researchers are yet to determine what’s causing the fat to thrive in the airways.
Through cross-examination of the samples, researchers determined that the level of fatty tissue correlated with the body mass index (or BMI) of the individual — more weight meant more fat.
The build-up is described to be similar to what happens when fat attaches itself to the heart. Likewise, scientists believe that an increased fat build up in the lungs could lead to an increased strain in the lungs.
“We’ve found that excess fat accumulates in the airway walls where it takes up space and seems to increase inflammation within the lungs,” says physiologist Peter Noble, from the University of Western Australia.
This inflammation caused by fat deposits is also being pointed to be a cause for increased risk of asthma, especially for those with higher body weights.
Initially, scientists believed that asthma is caused by an increased pressure for the lungs to perform due to the excessive body weight. Asthma itself has been linked to being more common with people that are overweight and obese.
“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,” Noble said.
It appears the fat actually alters the structure of the airways and increases inflammation, which is linked to asthma.
On the other hand, researchers are keen to determine whether the fatty deposits can be removed with weight loss.
“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,” says Thierry Troosters, president of the European Respiratory Society, who wasn’t involved in the study.
“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.”