March 10th, 2010
04:28 PM ET

Longtime smoking cuts Parkinson’s risk dramatically

By Matt Sloane
CNN Medical Producer

[cnn-photo-caption image=http://i2.cdn.turner.com/cnn/2010/images/03/10/story.smoking.gi.jpg]

It's a catchy headline – smoking cuts Parkinson's risk dramatically – and it appears to be true, but researchers at the National Institute of Environmental Health Science don't want you to start smoking.

"Nobody should advocate smoking to prevent Parkinson's disease," said Dr. Honglei Chen, a tenure-track investigator at the Institute. "It’s important to make that very, very clear."

The study, released today in the journal Neurology looked at the lifetime smoking history of more than 300,000 people, and confirmed the inverse relationship between smoking and Parkinson's disease, established in earlier scientific studies. But, researchers say they've found a critical new piece to the puzzle: It appears to be the length of time one has been a smoker – not the number of cigarettes smoked – that has the most effect on disease risk reduction.

"People who smoked more than 40 years had a 46 percent decrease in Parkinson's disease risk," said Chen. "Whereas people who smoked between one and nine years had only an 8 percent decrease in risk."

Chen, the lead study author, and his colleagues cannot yet identify the reasons behind this staggering link, but say when they are able to determine which chemicals in the cigarettes seem to be have a protective effect, they hope to be able to develop a drug that can mimic the effects of smoking, without the harmful risks.

"I think the findings are very important, but it is time now for scientists to search for the active chemicals, and to understand biological mechanisms."

Smoking continues to be the leading cause of preventable death in the United States and has been linked to an increase in heart-disease risk, stroke risk, and several types of cancers.

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soundoff (104 Responses)
  1. Maria H-Miami

    I'm confused, I thought they said that Stem Cell Research was the answer to finding a cure to Parkinson's and Alzheimer's disease. Didn't John Kerry say that Stem Cell Research would also find the cure to spinal injury? So, why are they looking into smoking?

    March 10, 2010 at 18:53 | Report abuse | Reply
  2. Carol

    Tourettes, now Parkinson's? Hmmm... Seems the witch hunt and ridiculous taxation of cigarettes will soon be over.

    I'm sure food additives, especially diet foods cause more health problems than cigarettes... Maybe some day they'll figure it out!?!

    It's about time!

    March 10, 2010 at 19:01 | Report abuse | Reply
  3. obvious sue

    well, exactly how many people with 40 or more years of smoking have had a chance to exhibit Parkinson's disease? Maybe they're all dying from heart disease, stroke, and several types of cancers?

    March 10, 2010 at 20:05 | Report abuse | Reply
  4. kittlepops

    yeah, but that whole "cancer" thing is a real drag too.

    March 10, 2010 at 20:06 | Report abuse | Reply
  5. Amanda Whitcraft, PT

    The incidence of Parkinson's Disease and other Parkinsonian Syndromes increase with age. Did this study control for age? I wonder if people who smoke 40 years have a decreased life span and thus a lower incidence of PD?

    March 10, 2010 at 20:40 | Report abuse | Reply
  6. Jim G.

    So when I die of lung cancer, at least it wasn't Parkinson's?

    March 10, 2010 at 20:43 | Report abuse | Reply
  7. Charles

    I'm not quite sure I can grasp what they're saying, because I smoked for forty years and quit cold turkey. I have been a diagnosed Parkinson's patient for three years. My symptoms are progressing rapidly and I don't have limitations, just challenges. I believe that like Parkinson's patients where no two progress the same, the studys results are a fluke or luck or kismet.

    March 10, 2010 at 20:47 | Report abuse | Reply
    • Griffin Meyer

      Like any study, the results are based on averages. Obviously, not everyone falls into the 'average' category.

      July 13, 2010 at 03:03 | Report abuse |
  8. Robin

    As a long time smoker – 35+ years – I know that this new information can be a way to justify continuing. I also know it should not be – any more than consuming red wine (which I also do in abundance) should be a good thing despite scientific research that red wine (in moderation) can be good for health.

    We all risk our lives every day – smokers more perhaps than others. I'm glad I may not get Parkinson's disease on top of emphysema and lung cancer. I know my risks, I choose to continue to take those risks and hope that I will be able to take my own life (since I am already doing that anyway) when these things consume me.

    March 10, 2010 at 20:48 | Report abuse | Reply
  9. pam

    it really annoys me that this article does not discuss and breakdown the simplicity that nitotine patches acheive similar results as well as reduction in symptoms in patients with active parkinsons. it has to do with the metabolic pathways that the chemicals are processed in via the body. how about expanding this to inform the general public not just those with medical educations? if you are at risk genetically or symptomatically, use a patch and keep a tally of your response, and do some research for your own benefit, god bless you!

    March 10, 2010 at 20:51 | Report abuse | Reply
  10. Interesting

    The length of time a person has been smoker is the important factor here which means that a longtime smoker who is less susceptible to smoking related diseases such as cancer and the like is not only less susceptible to Parkinson's disease, but others diseases as well. In other words, it is not the fact the person is a smoker, but rather the fact the person is genetically well equipped to handle, or fend off diseases that other can't.

    March 10, 2010 at 20:52 | Report abuse | Reply
  11. JJ

    So you don't get Parkinson's but you die an interesting death with lung cancer or emphysema or some other disease. Frankly, if anyone thinks this is a justification to continue smoking, we're talking Darwin here, classic gene pool elimination for the benefit of the species.

    March 10, 2010 at 20:52 | Report abuse | Reply
  12. James Little

    It has long been suspected that tobacco use (especially cigarettes) seems to calm many people whom suffer certain mental illnesses. One strongly suggested link may be the way nicotine reacts with neurotransmitters in the brain, especially dopamine, which is usually deficient in Parkinsons sufferers. Perhaps one day science will prove whether this is in fact true, and that in time, nicotine, or another substance in tobacco, may one day be used to prevent or treat Parkinsons disease or even one of the many other neurlogical illnesses that plague society.

    March 10, 2010 at 21:01 | Report abuse | Reply
  13. Bren

    Interesting news indeed, except that it doesn't apply to this ex smoker who, despite smoking for 50 years, was diagnosed with Parkinson's ten years ago and only quit smoking three years ago. . On the other hand, perhaps smoking may explain why my disease is progressing relatively slowly. No mention is made though of the effects of smoking once one has PD. In my case I found that I would shake uncontrollably while smoking the cigarette and for a short while after, despite taking my medications which work very well otherwise.. But regardless of the positive effects smoking may have, it should come as no surprise that I also suffer from COPD which is a far more debilitating disease for me than my Parkinson's......

    March 10, 2010 at 21:09 | Report abuse | Reply
  14. commonsense

    I guess it's hard to develop Parkinson's if you are dead from lung cancer.

    March 10, 2010 at 21:12 | Report abuse | Reply
  15. Ann

    My mother who started smoking Camels at age 16 and continued in to her 70's died at age 94 from advanced Parkinsons

    March 10, 2010 at 21:20 | Report abuse | Reply
  16. DJ

    Didnt Michael J. Fox smoke for many years?

    March 10, 2010 at 21:27 | Report abuse | Reply
  17. Dustin G. Basham

    Perhaps it's not a protective effect...maybe it is the challenge to the immune system posed by cigarettes that causes the immune system to ramp up forces against damaged tissue.

    March 10, 2010 at 21:30 | Report abuse | Reply
  18. Bill

    Since long term smokers had the lowest incidents of Parkinson's.

    It could be that many smokers prone to Parkinson's died from cancer or other diseases attributed to smoking before Parkinson's could manifest itself. Thus, they were never counted.

    March 10, 2010 at 21:36 | Report abuse | Reply
  19. Joe

    Is anyone considering that these people are dying of cancer before they develop Parkinson's?

    March 10, 2010 at 21:41 | Report abuse | Reply
  20. Alex

    Remember, this study only shows an association between cigarettes and decreased risk of Parkinson's, not a causal relationship between the two.
    Perhaps, it is not a chemical in the cigarettes that reduces the risk of Parkinson's, but instead an underlying genetic makeup of the brain, which causes one to have both an addictive personality (hence more smoking) and at the same time less chance of developing Parkinson's.
    Afterall, Parkinson's disease is partly due to decresed levels of dopamine, a brain chemical which is known to play a role in addiction. Therefore, those that smoke may have been born with genes that cause higher levels of dopamine, which cause their addiction, and at the same time protect them from Parkinson's.
    Just a thought. Don't start smoking yet.

    March 10, 2010 at 21:46 | Report abuse | Reply
  21. Iva

    What effect does smoker's living shorter lives have on the study. If you smoke for 40 years you have a lower chance of living to old age and hence a lower chance of getting Alzheimers

    March 10, 2010 at 21:56 | Report abuse | Reply
  22. Jay

    So the National Institute of Environmental Health Science hasn't yet been able to identify the reasons behind the staggering link. Could it possibly be that Parkinson's occurs in direct relation to decreased dopamine levels in the brain and that nicotine stimulates dopamine production? You'd think this would be the obvious link and that someone familiar with Parkinson's would put to two together.

    March 10, 2010 at 22:14 | Report abuse | Reply
  23. Sven

    Could it be that smokers just die too young to exhibit Parkinson's? That would explain (on a statistical basis) the statement:

    ["People who smoked more than 40 years had a 46 percent decrease in Parkinson's disease risk," said Chen. "Whereas people who smoked between one and nine years had only an 8 percent decrease in risk."]

    46% decrease in Parkinson's relative to 8% because the long-term smokers mostly died before!

    It could not be that obvious, right?!?

    By the way, I am a 5-year smoker trying to quit! Wish me luck!

    March 10, 2010 at 22:18 | Report abuse | Reply
  24. Ahmad Hajj, M.D., FCCP

    Is it possible that smokers die sooner and therefore they don't have a chance to develop full fledged Parkinson's disease?. I bet you that despite the warning by the authors for people not to smoke in order to reduce the risk of Parkinson's disease the findings of their study will definitely be used by some smokers to justify their deadly habit.

    March 10, 2010 at 22:40 | Report abuse | Reply
  25. Mary Eye

    My mother smoked for 50 years. Her smoking may have slowed the onset of Parkinson's, but it definitely didn't stop the disease. I sincerely hope that not one person will try smoking as a preventive measure. As with most diseases, genetics play the biggest part in the what happens. Mom had so many other illnesses related to her smoking that the truth is that it's amazing she lived to eventually have Parkinson's. Smoking reduces the quality of one's life in every way.

    March 10, 2010 at 22:40 | Report abuse | Reply
  26. Manny Hillman

    What is missing from your article is the number of nonsmokers who got Parkinsons disease and the number of smokers who got Parkinsons disease. Without these numbers. it is impossible to evaluate if the 46% decrease is statistically significant. The total sample size is irrelevant to the statistics. For example, a reduction from 11 to 6 would be about 46%, but statistically insignificant. Within two standard deviations, these numbers are the same.

    March 11, 2010 at 06:30 | Report abuse | Reply
  27. Cheryl Green

    I think you are on to something here. I have read other articles alluding to a connection between smoking and PD.
    I am a 60ish female who had smoked about 40 years (not alot-sometimes more non smoking than smoking) and diagnosed with PD about 15 yrs ago–considered early-onset. My disease has remained somewhat mild but I am on some pretty high doses of medication for PD.
    In my experience, I KNOW that there is a direct correlation between smoking and PD and/or meds because I used to use a cigarette sometimes to help me control tremors which worked. I also know first-hand the correlation between smoking and dropping my blood pressure (which is already low).
    I am howwever, an entirely smoke-free person for about a year now and love being so but I would also love to find that ingredient that could help with my PD symptoms (in the past).
    I stopped smoking for completely different reasons and consider myself lucky to have escaped long term damage (so far). I also must say that I do not find a difference (except perhaps in my blood pressure ) in my PD.
    Two conclusions: smoking for a long time did NOT protect me against PD (but I do think that it was a help in not getting a worse case than I have; and, I believe, there is a correlation. I do wish for a cigarette only when I am experiencing tremors though I have not taken one and have managed to handle my tremors but it takes much longer. I do not have the same craving nor effect with the rigidity. Please keep me posted.

    March 11, 2010 at 06:36 | Report abuse | Reply
  28. Rob

    So the older you are without Parkinson's, the less likely you are to get Parkinson's. Translation: Parkinson's manifests itself primarily as a disease of older people, not of younger people. The role of smoking or not smoking the hypothesis? Probably nothing, but the study was funded nonetheless.

    March 11, 2010 at 08:02 | Report abuse | Reply
  29. David Montez

    The more likely explanation for this finding is that long time smokers die of CANCER before they would have otherwise have developed Parkinson's Disease. Cancer develops earlier in general,especially for smokers, so these longtime tobacco addicts simply died before the Parkinson's Disease they would have otherwise later developed had time to take hold.

    The same stat is surely true for long-time heroin addicts or AIDS victims - they no doubt have a reduced occurrence of Parkinson's too! it doesn't mean there is any link or causality between AIDS and Parkinson's.... the reason is, unfortunately, that they die of the earlier onset diseases first! Duh.

    Scientists and the media need to think carefully and see the big picture before publishing such uncorrelated nonsense.

    March 11, 2010 at 08:06 | Report abuse | Reply
  30. Hillcoguy

    Hey! Maybe alot of those smokers wouldn't have gotten parkisons anyway...and the smokers most vulnerable died early?

    March 11, 2010 at 08:10 | Report abuse | Reply
  31. Kristal

    Interesting, since Parkinson's runs in my family (grandfather, mother and brother), although, oddly enough my grandfather and my brother (50 yrs old) both have smoked most of their lives. I'm also a smoker and am hopeful that perhaps one good thing will come from this horrible habit that I seem to have a terrible time kicking.

    March 11, 2010 at 08:17 | Report abuse | Reply
  32. Raille Witshiz

    Perhaps it's not the smoking. They say long term smoking. Maybe watever stops the person from being killed from the smokign also stops them from getting Parkinsons. Maybe it's not a causal relartionship but a dual immunity.

    March 11, 2010 at 08:33 | Report abuse | Reply
  33. Yogi

    This disturbs me – "Chen, the lead study author, and his colleagues cannot yet identify the reasons behind this staggering link"

    Medical science needs to PROVE things. It is very unfortunate that we start taking empirical evidence as the scientific evidence and believe it to be true. I can prove to you a very high correlation between the number of times a dog barks in Korea with the number of times a donkey brays in Nigeria – will that PROVE anything?

    I was a smoker for 22 years and just quit 5 months ago. Best period of my life has begun now. And as re the Parkinson's – after all, what is it? Shaking of one's hands? Mine shook when I was a smoker especially when I didn't get my drug for many hours at a time – didn't I have Parkinson's when i was a smoker?

    March 11, 2010 at 08:35 | Report abuse | Reply
  34. Jenny

    Michael J. Fox smoked for years leading up to his Parkinson's diagnosis- obviously, he didn't smoke for 40 yrs or longer, but it's interesting that the man who is probably known as the "face" of the disease was himself a smoker at one time. I know there are exceptions to every study and it's not a hard rule that smoking will prevent the disease...Fox just stood out in my mind, though. Interesting.

    March 11, 2010 at 08:48 | Report abuse | Reply
  35. NE

    Did the studies include other eating and/or drinking habits of the long-term smokers? There could be other factors that help reduce the risk of Parkinson's besides the smoking factor.

    March 11, 2010 at 08:52 | Report abuse | Reply
  36. Klaatu

    well well well....smokers just moved up on the social ladder just below crack addicts......Im not sure how smokers became the demons of the decade, but they have.....obesity and alcohol are far more dangerous and kill more people than smoking ever has...but you dont see people making drinkers have their martinis in the alleys or the fat people eat the parking lot 50 feet from the door....

    March 11, 2010 at 08:59 | Report abuse | Reply
  37. Joyce

    Well isn't that something. I smoked heavy for over 30 yrs before quitting. I'm healthy. My dad had Parkinsons Disease and never smoked. Looks like there may be something to this study.

    March 11, 2010 at 09:01 | Report abuse | Reply
  38. Maurine

    This is the biggest bunch of hooey I've ever heard.

    My mom smoked constantly for over 40 years, and has been smoke-free for 14 years. A few years after she quit she developed very mild emphysemia (which could have been MUCH worse if she had kept smoking), but it was her being diagnosed with Parkinson's that got to me. I've heard that continual exposure to insecticides can help instigate Parkinson's, and cigarettes contain a natural poisonous insecticide called NICOTINE. She has to take several different medications, and has had several falls from weakness in her muscles. Oh, and she still to this day chews nicotine gum.

    This is like that "research" several years ago (15 or so?) that decreed people did not need 400 IU of vitamin D, whereas vitamin makers reduced their "D" levels to 100 or 200 IU and rickets began to come back. Bull.... Now we know for a fact through several different research programs over many years that people indeed need more than 400 IU daily, and often 1000 IU to maintain health.

    March 11, 2010 at 09:12 | Report abuse | Reply
  39. Jim

    The effects of smoking have been praised and slammed for a number of reasons. When first identified an a hazard, formaldahyde was the additive that was so deadly. We have seen the Government condemn mobile homes based on the forfaldahyde presence, declaring them to be unsafe for habitation by the homeless. The whole cigarette statistics game is gerbage science aimed at protecting the chemical industry. Get some solid statistics and not this crap.

    March 11, 2010 at 09:12 | Report abuse | Reply
  40. julieh

    Is it possible this link could be because smokers are more "risk takers" and there is a known link between Parkinsons disease and type A personalities or people who are generally more uptight, controller personalities or "rules" people? I have read several articles with these findings... my mom has parkinsons and definitely fits that profile. Just a thought....

    March 11, 2010 at 09:14 | Report abuse | Reply
  41. Eric R

    It's a fascinating connection, and certainly very provocative. My main question would be whether it was only cigarette smoking that showed this link, or whether other types of smoking (pipes, cigars, etc) also showed the connection.

    March 11, 2010 at 09:26 | Report abuse | Reply
  42. Rodney

    Is it possible that it is not smoking that is decreasing the risk, but the act of smoking that does. I am refering to the two to five minute stress relief that having a smoke provides.

    March 11, 2010 at 09:34 | Report abuse | Reply
  43. john

    Could it be that the majority of people with Parkinson's that did smoke were already dead from smoking and not represented in the study group?
    The surviving pool of people would then be skewed due to a disproportionately stronger genetic constitution.

    March 11, 2010 at 09:44 | Report abuse | Reply
  44. John Rajkumar

    Isnt it logical to assume that people who can survive a life time of smoking are probably capable of surviving most anything, and you cant get a statistically relevant sample size of life time smokers( when compared to all life time smokers) because most of us die before Parkinsons can set in?

    March 11, 2010 at 09:45 | Report abuse | Reply
  45. Tanya

    And this is what millions of dollars in research money gives us? Seriously? Pretty soon smoking will be healthy again!

    March 11, 2010 at 09:47 | Report abuse | Reply
  46. Katie

    My mom was diagnosed with Parkinson's about four years ago. She had been a smoker for 36 years at the time of diagnosis. Her symptoms have progressed rapidly, so I don't think that smoking has slowed the progression of the disease, either.

    March 11, 2010 at 09:48 | Report abuse | Reply
  47. Bilbo Billsworth

    Maybe the genes that confer risk for Parkinson's disease also lead to lung cancer, COPD,vascular disease, etc. so that smokers who are predisposed to Parkinson's disease die from smoking-related lung disease before they have a chance to develop Parkinson's disease

    March 11, 2010 at 09:48 | Report abuse | Reply
  48. Brandt

    Yes, and they (doctors) also used to say that smoking one cigarette per day was the equivalent of exercising. It would take a lot more proof to convince me that any of this has true merit in saving lives. This is just hearsay and tabloid trash as far as I am concerned.

    March 11, 2010 at 10:10 | Report abuse | Reply
  49. Evan

    To clear up a couple things:
    Yes, the study "controlled for age", meaning that the lower risk of Parkinson's is not just because those who smoke die earlier.

    Also, smoking is extremely common and Parkinson's is relatively common. This study just discusses a relative risk reduction so there will still be hundreds of thousands of people who smoke AND still get Parkinson's. Don't be surprised by this.

    And no, you should not use the reduction in risk of Parkinson's to justify continued smoking.

    March 11, 2010 at 10:13 | Report abuse | Reply
  50. Stephen Polin

    My mother smoked two packs of cigarettes a day from the time she was 16 until she turned 40. At 37, she was diagnosed with Parkinson's Disease. Having quit at 40, she was able to live until the age of 82 shaking out of control for much of the time until she was around 78 when her muscles froze and she remained motionless and unable to communicate with even a grunt until the time of her death.
    Research surveys such as these are questionable in many respects. The saddest observation is that the time for this study could have and would have been better spent looking for cures, not "possible" links. Whether one smokes or not should not be the criteria for the cause or sooner or later, smokers may be denied treatment. Many people develop PD that do not smoke, just as many non-smokers develop lung cancer.

    March 11, 2010 at 10:14 | Report abuse | Reply
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