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 ideathat those who have
spent years as smokers don’t get PD as often as non-smokers.
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
centers in the United States, saysCornelia
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 studyfrom 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.
