Methamphetamine is currently one of the most widely used addictive drugs currently on the market, with an estimated 35 million users and counting. Its negative effects - both on communities and health of individual users - have been well-documented. It destroys brain cells, prompts tooth decay, and weakens heart muscles.

Despite all of the many reasons that meth is destructive, scientists in Taiwan have found an unlikely health benefit. Researchers from the National Health Research Institutes and Linkou and Chang Gung University School of Medicine have found that meth may have flu-fighting properties.

Because meth suppresses the immune system, it has been found that the drug increases the risk for developing human immunodeficiency virus (HIV). Researchers wanted to discover if meth's immune-suppressing qualities also can increase meth users' risk for getting sick with the flu or whether the drug increased the severity of the virus.

The researchers obtained human lung epithelial cells, which line the surface of the lungs. The cells were exposed to methamphetamine in varying quantities before being exposed to influenza A. Influenza A viruses often cause epidemics and pandemics of respiratory illnesses. Then the researchers left the cells alone for up to two days.

After 30 to 48 hours, the researchers had found that the meth-exposed cells had far fewer influenza viruses left alive, compared to the control group of regular human lung epithelial cells. This indicated that meth lowered, rather than increased, risk of infection of the disease. In addition, to the researchers' surprise, they found that the more meth to which the cells were exposed, the less the virus reproduced.

"We report the first evidence that meth significantly reduces, rather than increases, virus propagation and the susceptibility to influenza infection in the human lung epithelial cell line," the researchers write.

Obviously, no one recommends that anyone develop a meth habit during this flu season. But researchers hope to harness exactly what property meth has in order to help people fight the virus.

The study was published in PLoS One.