Many of you will be aware of how fatty deposits in the arteries can increase the chances of developing heart problems, but now scientists have found early evidence that the same kind of obstruction can occur in the lungs – and this can be related to asthma.
It is already known that overweight people have a higher risk of asthma. Until now, it was believed that the connection could be caused by extra pressure on the lungs or additional inflammation in the body. There is now evidence that fat deposits can also play a role.
Using material gathered from an earlier study, researchers examined lung tissue samples from 52 dead people: 15 without reported asthma, 21 with reported asthma, but died from something else, and 1
Nearly 1400 samples were analyzed using dyes to emphasize respiratory structures.
What they found was surprising – the accumulation of fat (fat cells) in the walls of the airways.
Moreover, the level of adipose tissue associated with an individual's body mass index (or BMI) – more weight means more fat.
"We have found that excess fat builds up in the walls of the respiratory tract where it takes place and seems to increase inflammation in the lungs," says physiologist Peter Noble of the University of Western Australia.
" this causes thickening of the airways, which limits the flow of air into and out of the lungs. This could at least partly explain the increase in asthma symptoms. "
This is the first fatty accumulation seen in the lungs, although they occur in organs other than the heart, including the liver.
this does not rule out previous hypotheses about how extra weight makes asthma more likely, it may be another consideration, as it seems that fat actually changes the structure of the airways and increases inflammation, which is again associated with asthma.
The exact mechanism, co it causes the appearance of fat in the respiratory tract, it is currently not clear – this is something that we will have to wait for the next batch of research, and it will also be important to test more people out of the 52 participating here.
Another question is whether the effects can be reversed with weight loss – whether with regular exercise and a healthy diet, the levels of fat inside the lungs will begin to decrease as the total weight of a person decreases.
What is certain is that we need a better understanding of obesity and its effects, as well as better ways to deal with it and quickly – by 2025 it is estimated that 18 percent of men and 21 percent of women worldwide will be classified as obese.
A recent study compares obesity with infectious disease in a way that we can "catch" unhealthy behavior by these people around us.
What has been done in the last study offers another reason why maintaining a healthy weight is so important for the proper functioning of the human body – and the more we know about it, the better we can strive for it.
"This is an important finding about the relationship between body weight and respiratory illness because it shows how being overweight or obese can worsen symptoms in people with asthma," says Thierry Troosters, president of the non-participating European Respiratory Society.
"This goes beyond simple observation in obese patients needing to breathe more with activity and exercise. Observation points for real changes in the airways that are associated with obesity. "
The study was published in European Respiratory Journal .