Cigarettes and Tobacco News

Apr 9, 2007 -- People who smoke cigarettes and drink coffee are less likely to have Parkinson's disease. The same can't be said of those who take aspirin.

Those are the conclusions of a new study co-authored by a researcher at the University of Miami School of Medicine.

Despite the irony of seeming to say something nice about smoking, it's a perfectly serious study, says William Scott, Ph.D. epidemiologist at the UM medical school. And he's not suggesting you start, or continue, smoking.

"Oh, no. Certainly not," he says. "The negative effects of smoking would greatly outweigh any benefits in terms of Parkinson's disease. What we hope is to isolate what it is about smoking and design treatments that will give people the good things without the bad."

Nor is he telling you to move your personal effects to a table at Starbucks.

"We don't know whether the differences are from a direct impact of coffee on Parkinson's or something else that's indirectly linked," he says.

"These things are complicated."

Parkinson's is a degenerative neurological disease that affects one in 100 people over the age of 60, although 5 to 10 percent of cases occur in people 40 or younger, according to the National Parkinson Foundation.

In the study, done with Duke University, researchers selected 356 people with Parkinson's disease and 317 family members without the disease to serve as a control group, since they would have similar genes and live in similar environmental conditions. They found that:

People with Parkinson's were only about half as likely to ever have smoked and about one-third as likely to be current smokers, as people without the disease.

The more coffee people drank, the less likely they were to have Parkinson's.

Aspirin, Ibuprofen, Naproxen and other drugs in the class called "non-steroidal anti-inflammatory (NSAID) medications" provided no protection against Parkinson's.

Earlier studies had hinted at cigarette-coffee-aspirin links to Parkinson's, but this was the first formal one comparing family members, including siblings, parents, children and cousins, Scott said.

The researchers do not claim that cigarettes and caffeine act alone in fighting Parkinson's. They suspect the two factors interact with an individual's genetic makeup.

"Given the complexity of Parkinson's, these environmental factors likely do not exert their effects in isolation, thus highlighting the importance of gene-environment interactions in determining susceptibility. Smoking and caffeine possibly modify genetic effects in families with Parkinson's," the study says. Researchers don't know whether nicotine is the compound that protects against Parkinson's, Scott says. Other researchers have tried treating the disease directly with nicotine without conclusive effect, he says.

"The problem is there are over 4,000 compounds in cigarette smoke," he says.

One theory: Both caffeine and smoking increase the body's supply of the "pleasure hormone" dopamine. And typically, as people develop symptoms of Parkinson's disease, they begin to lose the neurons that produce dopamine.

"There's a connection among all these things," Scott says.

A next step is to further explore the interaction of caffeine and nicotine with an individual's genetic makeup to see who is and isn't protected from Parkinson's by the two substances, Scott says.

"We're taking these data and overlaying genetic data to see if we can identify ways in which genes and the environment can work together to reduce Parkinson's disease." The study is in the April issue of Archives of Neurology, a publication of the Journal of the American Medical Association.

Study subjects were recruited by doctors at Duke University Medical Center, and Duke researcher Dana B. Hancock was a co-author of the study.

Individuals with Parkinson's were evaluated in clinics. They and their relatives were then interviewed by telephone about use of cigarettes, coffee and aspirin. Dosages were recorded in "pack-years" for cigarettes, "cup-years" for coffee and "tablet-years" for aspirin.