June 24, 2009

Study: Smoking linked to brain damage

A compound in tobacco provokes white blood cells in the central nervous system to attack healthy cells, leading to brain damage, researchers in India said.

Study leader Debapriya Ghosh and Dr. Anirban Basu of the Indian National Brain Research Center said the research centers on a compound known as NNK, common in tobacco.

NNK is a procarinogen, a chemical substance which becomes carcinogenic when it is altered by the metabolic process of the body, the researchers said.

Unlike alcohol or drug abuse NNK does not appear to harm brain cells directly; however, the research team said it may cause neuroinflammation, a condition that leads to disorders such as multiple sclerosis, the study said.

Considering the extreme economical and disease burden of neuroinflammation related disorders, it is extremely important from a medical, social and economic point of view to discover if NNK in tobacco causes neuroinflammation, Ghosh said.

The study, scheduled to be published in the July issue of the Journal of Neurochemistry, suggests NNK provokes an exaggerated response from the brain's immune cells, known as microglia. Microglia cells act as destroyers for the brain by attacking damaged or unhealthy cells. However, when provoked by NNK these cells start to attack healthy brain cells rather than the unhealthy cells they are supposed to attack, the study said.

The study also suggests that second hand smoking may lead to the same neuroinflammation conditions, the researchers said.