Parkinson's disease (PD) is a neurodegenerative disease that involves the loss of a specific group of neurons in the substantia nigra that produce dopamine. Sufferers experience a range of symptoms, including a tremor, other motor problems, depression, and cognitive disturbance. The disease itself is not fatal, but involves severe reduction in quality of life and the symptoms can often cause complications such as choking or pneumonia in advanced PD patients.

As an undergraduate sitting in neuropharmacology lectures, I was interested to hear that smoking was inversely correlated with PD; that is, people who smoked were less likely to develop the disease. Whether that link was causative, in that nicotine was neuroprotective for PD, or correlative, in that PD-prone patients had an aversion to nicotine, was not clear. Other research has identified caffeine and nonsteroidal antiinflammatory drugs (NSAIDs) such as ibuprofen as possibly having a protective effect.

A new case study published tomorrow in the Archives of Neurology has examined the prevalence of PD, smoking, caffeine, and NSAID usage in 356 patients and 317 of their family members. The study, conducted by a team at Duke University Medical Center, found that although there was no link between PD and NSAID usage, both smoking and caffeine intake were inversely related to PD.

Now, I don't want this to sound like an advert to start smoking; not contracting PD is a little pointless when you drop dead from lung disease or a heart attack, and any neuropharmacological reason for nicotine or caffeine protecting the dopaminergic neurons remains unknown. It is possible that these drugs suppress some genetic component of the disease, but only a great deal of further research will answer that question.