Heavy drinkers are at a much greater risk of developing lung problems, like pneumonia and life-threatening acute respiratory distress syndrome (ARDS), according to new research from Philadelphia's Thomas Jefferson University. Researchers suspect those with the disease of alcoholism are more susceptible to these lung diseases because the immune system in the lung is no longer strong enough to protect from infection and damage, the June 30 report concludes.
Similar to how alcohol begins to destroy the liver, researchers discovered that one of the keys to immune system failure in the lung is a build-up of fat. “We call it the alcoholic fatty lung,” says lead researcher Ross Summer, M.D. “The fat accumulation in the lungs mimics the process that causes fat to build up and destroy the liver of alcoholics.” The unique finding offers the possibility of a new treatment.
When people drink, liver cells begin to produce fat, possibly as a defense mechanism against the toxicity of the alcohol or because the body fuels itself on alcohol calories rather than fats. Over extended and frequent alcohol exposure, the fat accumulates and heavy drinkers develop “fatty liver disease.” The fat impairs liver function but can also cause scarring that eventually leads to liver failure.
The lungs also contain cells that make fat to coat the inner lining of the lung to keep the airways properly lubricated during breathing. Dr. Summer and colleagues explored whether these cells might behave in a similar way to liver cells after extended alcohol exposure by also accumulating fat.
After extended exposure to alcohol in rats, the researchers noticed that lung's fat-secreting cells doubled their production of triglycerides (a cholesterol) and increased free fatty acids by 300 percent compared to rats fed a non-alcoholic diet. The researchers also observed more fats in lung macrophages, which are immune cells that normally rid lungs of bacteria and sick cells. “It’s likely that the macrophages try to engulf the excess fat in order to protect the cells in the lung, but in doing so, they become less effective sentinels against infection and disease,” said Summer.
If the same process can be observed in humans – research that Dr. Summer is currently exploring – it would suggest that lipid-lowering “fibrate” drugs could be useful in treating alcohol-related pneumonia and in preventing the development of ARDS. Fibrates are not the same as the commonly-prescribed cholesterol-lowering statin drugs such as the brand Lipitor. Fibrates reduce the production of triglycerides and can increase HDL (good) cholesterol. Examples include the brands Atromid, Tricor and Lopid.