Improving MS outcomes: The smoke in our eyes!


Many of you will have registered themselves on the UK MS registry. This is an online registry that aims to monitor the motor, mood and treatment status of pwMS based on what we call patient-reported outcomes or PRO’s. This means that pwMS voluntarily fill out simplified MS questionnaires every 6 months after being prompted by MS email spam of the most honourable kind. Based on the responses of thousands of pwMS, UK researchers have looked into the association of current, former or never smoking and MS disease course.

The UK MS register verdict: 

1. Smoking is associated with worsening of motor function and walking range compared to non-smokers. Importantly, a direct relationship between smoking and the worsening of PRO’s is hinted by the fact that heavy smokers (for all the people still in denial: > 13 cigarettes per day) experience an accelerated rate of worsening compared to light smokers (<7 cigarettes). Moreover, there was a deceleration in the rate of motor deterioration following smoking cessation and the disease course became similar to pwMS who had never smoked. One of the reasons to explain these associations might be that nicotine activates white blood cells and leads to increased inflammation throughout the body. This theory also explains why smoking is not only linked to MS as an autoimmune disease, but also to rheumatoid arthritis, lupus erythematous, thyroid disease, … 

2. Although anxiety levels did not increase in pwMS experiencing worsening motor function, anxiety was consistently higher in current smokers and improved with smoking cessation. This implies that for at least a number of smokers it would be very valuable to be referred for psychological support as part of a smoking cessation strategy in which cigarettes are replaced by other coping strategies. 

3. The frequency of smoking among pwMS is unfortunately on par with the national UK average. These numbers emphasise neurologists need to invest time in increasing awareness about the negative effects of smoking on the MS disease course. The first step would be to systematically query about smoking status in clinics and to set up collaborations with smoking cessation clinics. 

As smoking is undeniably a form of addiction, I am well aware that rational arguments (read: evidence from a large UK MS registry, stroke risk, cancer risk, costs) are unlikely to make a difference to pwMS currently still smoking. Moreover, it is confronting to realise that smoking habits are not equally distributed among pwMS, and that people from non-white ethnic background who are already more vulnerable socio-economically are also more likely to smoke. Nonetheless, it would be a good idea to put more weight on lifestyle measures such as smoking cessation in MS guidelines. As any indoor smoker would reasonably say: let’s open the window! 

Were you aware of the association? Do you consider to stop smoking? What kind of information would make a difference for you? Please share your thoughts! 

Twitter: @SmetsIde

Disclaimer: Please note that the opinions expressed here are those of dr. Ide Smets and do not necessarily reflect the position of the Barts and The London School of Medicine and Dentistry nor Barts Health NHS Trust.

Brain 2021 Oct 8;awab385. doi: 10.1093/brain/awab385. 

The impact of smoking cessation on multiple sclerosis disease progression

Jeff Rodgers 1, Tim Friede 2, Frederick W Vonberg 3, Cris S Constantinescu 4, Alasdair Coles 5, Jeremy Chataway 6 7, Martin Duddy 8, Hedley Emsley 9 10, Helen Ford 11, Lennora Fisniku 12, Ian Galea 13, Timothy Harrower 14, Jeremy Hobart 15, Huseyin Huseyin 16, Christopher M Kipps 13, Monica Marta 17 18, Gavin V McDonnell 19, Brendan McLean 20, Owen R Pearson 21, David Rog 22, Klaus Schmierer 18 23, Basil Sharrack 24, Agne Straukiene 25, Heather C Wilson 26, David V Ford 1, Rod M Middleton 1, Richard Nicholas 1 3 27, MS Register groupAffiliations expand

  • PMID: 34623418
  • DOI: 10.1093/brain/awab385


The negative impact of smoking in MS is well established, however, there is much less evidence as to whether smoking cessation is beneficial to progression in MS. Adults with MS registered on the United Kingdom MS Register (2011-2020) formed this retrospective and prospective cohort study. Primary outcomes were changes in 3 patient reported outcomes (PROs): normalised MS Physical Impact Scale (MSIS-29-Phys), normalised MS Walking Scale (MSWS-12) and the Hospital Anxiety and Depression Scale (HADS-Anxiety and HADS-Depression). Time to event outcomes were clinically significant increases in the PROs. 7983 participants were included, 4130 (51.7%) of these had ever smoked; of whom 1315 (16.5%) were current smokers and 2815/4130 (68.2%) were former smokers. For all PROs, current smokers at the time of completing their first questionnaire had higher PRO scores indicating higher disability compared to those who had never smoked (∼10 points difference in MSIS-29-Phys and MSWS-12; 1.5-1.8 point for HADS-anxiety and HADS-depression). There was no improvement in PRO scores with increasing time since quitting in former smokers. 923 participants formed the prospective parallel group, which demonstrated that MSIS-29-phy 5.03, [3.71, 6.34], MSWS-12 5.28, [3.62, 6.94] and HADS-depression 0.71, [0.47, 0.96] worsened over a period of 4 years, whereas HADS-anxiety remained stable. Smoking status was significant at year 4; current smokers had higher MSIS-29-Phys and HADS-Anxiety scores (3.05 [0.22, 5.88], 1.14 [0.52,1.76]) while former smokers had a lower MSIS-29 score of -2.91[-5.03, -0.79]. 4642 participants comprised the time to event analysis. Still smoking was associated with a shorter time to worsening event in all PROs (MSIS-29-Phys: n = 4436, p = 0.0013; MSWS-12: n = 3902, p = 0.0061; HADS-anxiety: n = 4511, p = 0.0017; HADS-depression: n = 4511, p < 0.0001). Worsening in motor disability (MSIS-29-Phys and MSWS-12) was independent of baseline HADS-anxiety and HADS-depression scores. There was no statistically significant difference in the rate of worsening between never and former smokers. When smokers quit, there is a slowing in the rate of motor disability deterioration so that it matches the rate of motor decline in those who have never smoked. This suggests that smoking cessation is beneficial for people with MS.

About the author

Ide Smets


  • I was aware. It’s something I was asked about at most appointments!

    I did come across someone recently diagnosed on Twitter, and all it took for him to stop was a doctor telling him at diagnosis why he needed to stop. What a doctor says can have a huge impact. I had one doctor who really tried to scare me. I’m not sure what the point of that was because there were no lifestyle factors I needed to change! I still think he thought I was lying and that if he scared me I would tell the truth. Given the state of my MRI he refused to believe I had no regular symptoms, I was a few days away from running my first half marathon and I ended up spending the whole race worried I was getting the heat-related symptoms he didn’t believe I don’t get. Honestly that interaction had a negative impact on my health. But doctors really do have the power to cause a positive impact, and a few carefully chosen words can cause someone to change their behaviour.

    I come from a white middle class background where I had almost never had a reason not to trust a doctor before. I’m aware that people from other ethnic she socioeconomic backgrounds can’t take that doctor-patient relationship for granted. I wish doctors had enough time to spend with these patients to build that relationship. And the training to know how and why!

    • Good to know, because sometimes I doubt whether touching upon the smoking theme in clinics is really worth it in terms of smoking cessation vs. the antagonizing effect it has for certain individuals. Obviously, it’s never good to scare anyone.

    • Its called emotional intelligence. Sadly absent from so many doctors but an essential part in the training of nurses

  • Hello – I gave up smoking on diagnosis with MS but I do continue to vape. Is the evidence that nicotine on its own is inflammatory unambiguous? I have read the precise opposite in scientific abstracts, and there was that large Swedish study indicating that use of snus – snuff, which is very widely used in Sweden – was actually seen to have an MS-protective effect.

    So you have worried me!

    • The evidence mainly relates to smoking of nicotine containing cigarettes but it has not been pinpointed which component of the cigarette smoke is exactly responsible for the proinflammatory effect, and as outside of sweden nobody uses snuff it’s difficult to replicate…

      • I too quit smoking but continue to vape. As I understood it, nicotine has been shown to be neuroprotective in other diseases (Parkinson’s, Alzheimer’s) and linked to slower progression in MS in the Swedish study mentioned.

        So I’m also worried now :/

        • Also in vaping there are numerous toxic chemicals involved next to nicotine which have been associated with lung damage and cancer. There is just less research to back up all theses associations because it’s a relatively new habit.

  • I almost wish it was that easy to have something such as being a smoker to blame my MS on. I was never a smoker. Nor did I grow up with anyone in my household who smoked. Yet here I am progressive MS. And my Mom had severe Rheumatoid Arthritis most of her life & never smoked.

    • I am not so sure, sitting on the other side of this coin. I smoked until i was around 26 but from a young age when it was a ‘cool’ thing to do and cancer was just a thing that affected older people. 6 years after quitting was when my MS first appeared, possibly before but this is open to debate. I try not to dwell on it as the disease seems to be caused by a perfect storm of issues but often wonder if i would be in this position if i didnt smoke. I can see where you’re coming from, that it would be harder to take having led a clean life. Blaming yourself is not much fun either though

    • Good illustration of risk versus causality. Smoking/nicotine is just one piece of the puzzle, and even when pwMS smoke we don’t know which component of the smoke woud be really causal or whether it would be the socio-economic factors surrounding smoking.

  • Please also review:

    “Molecular Mechanism of Acrolein Toxicity”.,reticulum%20stress%2C%20and%20immune%20dysfunction.

    Acrolein appears to be a major component of cigarette smoke. There has been some research studying acrolein levels as a method of identifying activity in MS (I’m unaware of the outcome). I was exposed continually to acrolein (2-propenal) as a research chemist when younger and have three related outcomes including MS. My cancer surgeon was shocked that I was a lifelong non-smoker, then we figured out the workplace connection. It is hypothesized that I bioaccumulated this stuff because every time I lose weight, neuro symptoms kick up. I do find one of the protective agents listed in the Table extremely helpful and am in remission from the cancer.

    • Bingo! KC thank you for posting this link! The word biocide glared out at me! I’ve been saying this for a long long time. When you think about the chemicals used on say our pets and food that kill bugs (fleas, ticks, etc), and then ask how they work & realize that the chemicals are neurotoxins, you tend to become suspicious. I grew up in US back when they would fly over dusting crops not too far off from my backyard where I would be at play or the mosquito spray trucks would emit their toxins and back then no one whatsoever was told to go inside and close all your windows. Then a billion years later as an older adult, taking your child to adopt a kitten and told that it had an infestation of fleas upon coming in to the shelter but was treated with a capstar pill that basically kills the fleas within 30 minutes by attacking the fleas central nervous system, and then you ask, “what’s it doing to the poor kitten’s central nervous system?” And the reply is a shrug of the shoulders. It really gets your thinking wheels in motion. I have not 1 but multiple health issues listed in the article you shared! I too am not a smoker, nor was I ever, and no one in family either, so blaming MS on smoking baffles me other than we all know that smoking will affect a person’s health in general so it is safe to assume that it will make any disease worse. I am happy that you are a non-smoker as I am sure that would’ve impacted your health worse. And I am happy for you being in remission. Positive thoughts sent your way for continued remission.

      • Worst offenders are agricultural and rubber chemicals, certain solvents, dyes – I worked with them all. It’s a solid review. A pain management doctor started me on NAC in 2016 and my bladder recurrences and symptoms stopped. I found this article in 2018, checked out the list of protective agents – AHA moment.

        Most of us have some sort of environmental trigger – still needs the right (wrong lol) genetics, vitamin D status, etc. AND I was a chemist with a poor detox system (MTHFR), so … it’s likely not the same for all of us but it sounds like you and I share the trigger for sure.

          • I’m not certain if that would be considered medical advice, which would be frowned upon. Is it possible for you to work with a functional or naturopathic doctor?

  • There are several points I am going to illustrate, with the purpose only of description. I have no real intention other than to describe… 1) being addicted before you are born, 2) parents- one who smoked and one who didn’t, 3) a cousin with MS, 4) some of my adult nicotine experience, and 5) trying to transfer to vaping. Once a > 13 cigs per day smoker, I have been < 7 a day for 20 years. But I am struggling now to complete a transfer of addiction from cigs to vape only. But I believe I will get there. It isn’t easy, and I have to disregard some of what is said or implied here, in what seems to be the major theme of Dr. Smet’s article- (And yes, I do enjoy writing stuff that challenges the status quo, although I really have better things to do right now. But I think it’s important to share these bits of knowledge I have that Dr. Smets has seemingly asked for).

    1 & 2) My mother smoked when I was a fetus, and I am sure I was born addicted. My first hit of a cig, around 13, was wonderful! “Wow, what a feeling, this is really great stuff! It feels so familiar.” I do remember the experience. Fast forward… my father, a non-smoker, repeatedly telling me not to smoke…, to give it up. My mother and father (who lived in different parts of my home prior to divorce) both died of lung failure, at about the same age. My father’s death was brought on by Alzheimer’s. My mother’s by dementia caused by medical non-compliance (didn’t take her blood pressure meds). Neither were able to treat themselves/do anything about their loss of mind, helpless at the end. Neither knew what was going on. Couldn’t breath. Almost horrific. Same outcomes.

    3) My female cousin on my mom’s side, was diagnosed with MS a few years after me (both RRMS, 30ish). (No other familiar history, but such is not very well documented.) She lived a “pristine” upbringing. Never interested in cigs, no “reefer”, certainly no other 70’s drugs or psychodalia, no alch but perhaps a glass of wine or half a beer at a frat party. Me, the opposite (and I won’t go into that.) We are both about the same with our MS now, perhaps me a little better as I did Betaseron for 25 years and she was afraid of needles so she took the steroids path (that’s all there was in the early days). Same outcomes.

    I lived in North Carolina and Florida while in graduate school and at my dream job (licensed psychologist in OD setting) after college; both places are home to cheap affordable tobacco. So I smoked it up in the late 80’s and 90’s. When I moved out, I recall seeing the smoke stain on the wall when I removed the wall paintings and hangings. “Uhg”, I thought, “this isn’t good”. Lots of stress there. Sued my “dream job employer” for discrimination (MS), took my $ and moved. Got married. Had to smoke much less and do it outside of the house. That was 2000.

    So here I am. I do not entertain myself with “what ifs?” I’m 64 years, and I bet that whatever happens to me in the long run, it will not be much different than what happens to others, in the long run [same outcome]. But the short run… My brother successfully quit cigs via vaping, and he no longer vapes. The addiction just ran its course until he was no longer interested. He gave me a vape “machine” several years ago. I’ve been planning to quit “when I’m 64” (thanks Paul). So again, here I am.

    In behavior and psychology, I am prone to use a psychodynamic and existential orientation to explain what I see. However, in trying to dismantle my addiction, and although there may be some dynamic issues, the way it was put together was classical conditioning. Cigarette smoke is much more than nicotine, and for many if not most, the feeling associated with inhaling those 200+ carcinogens and other stuff in cig smoke, has been paired along with inhaled nicotine for a long, long time. Add to that, the reward value I have attached to taking a smoke- after I eat, taking a break after a completed task, just clearing my mind, all in a familiar location or doing something, like driving. On and on the pairing of the stimulus and response goes. So there is a lot of unlearning to do. I would rather keep my learning and not break apart a good part of my life, probably not different to most people. So wouldn’t it be nice to just “do” nicotine and cut out the other harmful stuff? There’s not much in the steam of non-flavored vape juice. I can still reward my self, in familiar ways and locations, just as before. I don’t have to change my whole life. Patches are OK, but you get a familiar rush and other stuff from vape.

    Thus far (since New Year’s), I am down to about 4 or 5 cigs a day, split into about 4 portions each cig. That makes for about 20 “light-ups” a day consisting of about 4 “drags”, or “hits” of “real cig”. Before taking a hit of the real stuff, I vape 4 hits. After the “real stuff” I take another 4 vape hits (all approximate). The objective is transfer my addiction- that is “all my nicotine + cig learning”, to vape only. Then, I’ll deal with the vape if and when I want. Perhaps it will fade like my brother’s addiction. Or I’ll die from something else while waiting. Same outcome.

    So that is my story Doctor. Take from it what you will. I also hope there is something in here for others.

By Ide Smets



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