Parkinson's disease occurs due to a loss of brain cells that produce a chemical messenger called dopamine. The symptoms of the disease include loss of balance, slower movement and tremors and stiffness in the face and limbs. There is currently no cure for the disorder.
The observation that cigarette smokers have a reduced risk for Parkinson's disease has long been known, and has raised the idea that nicotine may reduce the risk for the illness.
Tobacco belongs to a plant family called Solanaceae and some plants in this family, such as peppers and tomatoes, are edible sources of nicotine.
In general, vegetable consumption had no effect on Parkinson's risk. The more vegetables from the Solanaceae plant family that people ate, however, the lower their risk of Parkinson's disease.
This association was strongest for peppers, according to a study published online in the journal Annals of Neurology. This study included nearly 500 people who were newly diagnosed with Parkinson's and another 650 unrelated people who did not have the neurological disorder, which is typically marked by tremors and other movement problems.
The apparent protection offered by Solanaceae vegetables occurred mainly in people with little or no prior use of tobacco, which contains much more nicotine than the foods included in the study.
More research into the role of nicotine in Parkinson's disease is already underway; a nicotine skin patch is currently being tested in patients with early Parkinson's disease.
The above story is based on the May 09, 2013 news release by Wiley.
The research has been published in the Annals of Neurology, a journal of the American Neurological Association and Child Neurology Society :
Searles Nielsen S, Franklin GM, Longstreth Jr WT, Swanson PD, Checkoway H. Nicotine from Edible Solanaceae and Risk of Parkinson Disease. Ann Neurol, May 9, 2013 DOI: 10.1002/ana.23884
The U.S. National Institute of Neurological Disorders and Stroke has more about Parkinson's disease.