Across the board, physicians agree: There’s no doubt that smoking is bad for you. But is it possible that there’s just something about a cigarette habit that might lower a person’s risk of developing Parkinson’s disease (PD)? Epidemiological data (in which patterns in comparative populations are analyzed) has long supported the idea that those who have spent years as smokers don’t get PD as often as those who do.
Of course, smoking a pack a day to maybe prevent the onset of PD hardly makes sense — the adverse effects of puffing on nicotine cigarettes certainly outweigh any potential benefits. Still, the data on smoking and PD is too intriguing to ignore: looking collectively across many studies, it’s estimated that current smokers are 60 percent less likely to get PD than those who have never smoked. Which begs the question: Could there be a drug for PD hidden somewhere within the rolling papers? Researchers believe that maybe there is, and the potential therapeutic agent that they’re intrigued by is nicotine.
This month, an exciting development toward learning more about nicotine and PD: A clinical trial sponsored by The Michael J. Fox Foundation (MJFF) is launching in the United States to explore the potential therapeutic benefits of those very same nicotine patches that people take to try and quit smoking.
NIC-PD will enroll 160 PD patients in Germany and the U.S., providing some volunteers with nicotine patches and others with placebo patches, in order to determine if the real ones might have the potential to slow the progression of PD. Eighty of these patients will be enrolled at 11 centres in the United States, says Cornelia Kamp, the project manager of the American arm of the study.
“The drug used in the trial is the same exact drug from Novartis that people have used to quit smoking for many years,” explains Kamp, which is good news in terms of clearing hurdles associated with the therapy’s safety. She is hopeful that her team could have high level results from NIC-PD by spring of 2015. A best case scenario: The results both show that disease progression is slowed, and are convincing enough to encourage a larger follow-up study which could prove to be more definitive.
Of course, there are hurdles. Most imminently, explains the U.S. study Principal Investigator James Boyd, MD, of the University of Vermont, nicotine gets a bad rap with the public because of its relationship with tobacco and addiction. In smoking, it’s the bevy of chemicals in a cigarette and the process of smoking that can cause cancers, not the nicotine itself. Still, helping prospective trial participants, and PD drug developers alike, to understand its benefits could prove to be a challenge, due to nicotine’s reputation.
The good news for people with Parkinson’s, says Boyd, is that pre-clinical studies have shown that nicotine could protect dopamine-producing neurons in the brain from dying. But we’ve yet to see this effect in people. NIC-PD will be the first clinical study to begin to get to the bottom of this disease-modifying potential.
And there’s still much to learn about possible biological connections between nicotine and PD. To date, most human-based data around nicotine and Parkinson’s has been purely epidemiological, says Maurizio Facheris, MD, MSc. This means that there might be other ways to describe the relationship between nicotine and PD that aren’t “brain chemically-based.”
Here’s one such example of how epidemiological data can return scientific twists and turns: A past study from Matthew Menza, MD, found that people with PD tend to be less likely on the whole to be “novelty-seekers,” possibly because they have less dopamine in the brain (dopamine might inspire people to be more likely to seek out emotional stimuli). These individuals were also more likely to see smoking as a bad idea. On the other hand, the study found, “novelty-seekers” were more likely to take risks such as smoking, and they were also less likely to develop Parkinson’s. In short: Maybe those who are in the early stages of PD are just less likely to smoke because of how their brains are wired.
The good news is, NIC-PD is designed to begin to clear up some of these questions and determine if it’s the addition of nicotine in the body that could really be making the difference. In addition, MJFF is funding additional pre-clinical work to learn more about the biological potential of nicotine in the brain.
And there was more intriguing news from last January, when research published in Neurology, the medical journal of the American Academy of Neurology, found that a nicotine patch may improve the memory loss common in mild cognitive impairment (MCI), a condition that is often a precursor to Alzheimer’s disease.
The next few years could be telling as to whether nicotine might help to slow or prevent PD. Stay tuned for updates.
And, please, in the meantime, says Facheris, remember, it’s never a good idea to light up if you can help it. The potential good in nicotine is always outweighed by the toxins that enter into the body when smoking a cigarette. That’s the stuff that could produce cancers.