In a five-year animal study from The Parkinson's Institute suggests that nicotine treatment protects against the same type of brain damage that occurs in Parkinson's disease.

Nicotine's protective effect found in this study may explain the lower incidence of Parkinson's disease among smokers and suggests that nicotine may be useful as a potential therapy in the treatment of early-stage Parkinson's patients.

"While we would never recommend that people smoke, these results suggest that nicotine promotes the survival of dopamine-producing cells in animals with no overt Parkinson's symptoms," said David A. Schwartz, M.D., director of the National Institute of Environmental Health Sciences, the federal agency that provided funding for the study.

"These findings also have implications for its use in slowing the progression of Parkinson's."

"These studies were giving us clues that something in the smoke was reducing the incidence of Parkinson's," said Maryka Quik, Ph.D., a senior research scientist with The Parkinson's Institute and lead author on the study.

There is no explanation yet for the this effect of nicotine but the researchers believe that nicotine may stimulate the release of naturally occurring proteins called growth factors that play a key role in nerve cell growth and repair. Nicotine also may activate the immune system to protect the cells from MPTP-induced damage.

MPTP is an agent that produces a gradual loss of brain function characteristic of Parkinson's. In this study, experimental animals receiving chronic administration of nicotine over a period of six months had 25 percent less damage from the MPTP treatment than those not receiving nicotine.

Parkinson's disease, a progressive neurodegenerative disease caused by the death of small clusters of cells in the midbrain whose gradual loss results in reduction of a critical transmitter called dopamine (chemical messenger responsible for normal movement).

Study results are published in an on-line early release in the Journal of Neurochemistry (doi:10.1111/j.1471-4159.2006.04078.x).

Read more at The Parkinson's Institute.