5 Facts About Second-Hand Smoke’s Link to Serious Dementia

A new study has shown there may be a link between second-hand smoke, the involuntary inhaling of smoke from other people’s cigarettes, cigars or pipes, and developing a serious form of dementia. Here are five facts about this new study that you need to know.

1) Where Was The Study Conducted?

The study was conducted in China by scientists from Anhui Medical University, China and researchers from King’s College London, with the assistance from other researchers in the UK and USA. China is the world’s largest consumer of tobacco, with approximately 350 million smokers. China also has the most dementia sufferers, perhaps not surprising given dementia is associated with old age and China has the world’s biggest over-60s population, but the figure appears to be on the rise in a way not absorbed by a simple head count.

2) What Was The Goal?

Research has long indicated that exposure to second-hand smoke, alternatively termed passive smoking or environmental tobacco smoke (ETS), increases the risk of serious cardiovascular and respiratory diseases, including coronary heart disease and lung cancer. There have also been studies which have demonstrated a potential link between ETS and cognitive impairment. What researchers were still unclear about, however, was whether they could find a link between second-hand smoke exposure and an increased risk of serious dementia.

3) What Was the Methodology?

The study, published this week in Occupational and Environmental Medicine, took almost 6,000 people aged 60 and over from across five Chinese provinces. Researchers then assessed the group’s smoking habits, the level of exposure to second-hand cigarette smoke and level of dementia, the latter by using the Automated Geriatric Examination for Computer Assisted Taxonomy instrument.

4) What Were the Key Findings?

Researchers found that 626 participants (10.6%) had severe dementia syndromes and 869 (14.7%) had moderate syndromes. Of this group, the researchers discerned that participants who had been exposed to second-hand smoke had a “significantly increased risk” of developing severe syndromes, something they were able to track as dose-dependently related to exposure level and duration. The exact breakdown is available here. Most importantly, researchers were able to establish a significant increase in severe syndromes among “never smokers” who reported being exposed to ETS, as well as former/current smokers.

The researchers did not find a positive association between ETS and moderate dementia syndromes, however.

5) What Did The Researchers Say?

Dr Ruoling Chen, a visiting professor at Anhui Medical University, is quoted as saying: “Passive smoking should be considered an important risk factor for severe dementia syndromes, as this study in China shows. Avoiding exposure to ETS may reduce the risk of severe dementia syndromes. China, along with many other countries, now has a significantly ageing population, so dementia has a significant impact not only on the patients but on their families and carers. It’s a huge burden on society.”

Rouling goes on to say that, “More campaigns against tobacco exposure in the general population will help decrease the risk of severe dementia syndromes and reduce the dementia epidemic worldwide. The increased risk of severe dementia syndromes in those exposed to passive smoking is similar to increased risk of coronary heart disease – suggesting that urgent preventive measures should be taken, not just in China but many other countries.”‘


While many people in countries like the UK are insulated from second-hand smoking’s impact because of tough laws that restrict where smokers are able to light up, nearly 80% of the more than one billion smokers world-wide live in low and middle income countries that do not offer such stringent protections. In fact, the World Health Organization estimates that only 11% of the world’s population is protected by comprehensive health laws that manage this risk.

This study, then, points to a need for urgent action against smoking’s prevalence as well as tougher interim restrictions being taken seriously not just in developed countries but across the globe.


Related Reading:

Is Smoking Stealing Your Memories?

Quit Smoking Now And Live 10 Years Longer, Ladies

Should Smoking Be Banned in Cars?


Image credit: Thinkstock.


Past Member 3 years ago

There is good collection of the articles with informative stuff.
electronic cigarettes

Sheamus W.
Past Member 4 years ago

Hey nice post man! Thanks for incredible info.
green smoke

Duane B.
.4 years ago

Thank you for sharing.

Rodrigo G.
Rodrigo G.5 years ago

This is an excellent article, thanks for the information. I also believe that health care is important and that there are now many solutions for helping people who are alone or have certain problems. A virtual companion is one of those solutions and Gerijoy is the perfect one.
GeriJoy is an MIT and Blueprint Health affiliated company that has been recognized by organizations such as AARP as one of the most innovative companies in senior care. The GeriJoy Companion brings joy to families by providing companionship for seniors to improve mental health, and by reporting back to family caregivers to provide peace of mind.

The Companion is a software service that takes the form of a lovable and intelligent talking pet inside an Android tablet. It provides the emotional benefits of virtual pet therapy, and it also serves as an avatar for GeriJoy’s staff, who provide live conversational responses. Because the Companion may be controlled by an intelligent, compassionate team of humans, it can talk with the senior about anything, at any time of day. In particular, it tends to focus on regularly reminiscing about memories and reinforcing family connections. In doing so, it leverages photos and comments that family and friends can easily add through the Family Portal website. Through the Family Portal, friends and family also receive live updates about how their loved one is doing via a diary written in the voice of the Companion. The diary is enjoyable to read and can offer d

Vicky P.
Vicky P5 years ago

thanks :/

Alex H.
Alex H5 years ago

I'm not a doctor but I have done a lot of study into medical conditions.It seems to me that the major cause of dementia and all those other senility type conditions,is lack of oxygen to the brain,pointing clearly to circulation problems?!Dehydration of the brain is also a serious cause of brain dysfunction.Drink more pure,non-tap water!.It has been shown that many medications for blood pressure and cholesterol are actually decreasing the circulation of blood through the brain,therefore causing dementia?!As the body ages,and liver and kidney function slows down and weakens,no doubt the amount of fats and toxins circulating through the poor old brain,are not helping either.Then there are the accumulative neurotoxins found in vaccines and artificially sweetened foods and drinks,building up in the brain tissue!?It is very confronting to note that the vast majority of elderly people in nursing home and care facilities,are there because of dementia or Alzheimers disease.This epidemic is no mystery!

David W.
David W.5 years ago

Complete bullcrappy. Blind-test studies of groups of people where one group is composed of lifetime nonsmokers and the other of smokers who have smoked 3 pack years (a pack year is equal to smoking a pack a day for a year or the equivalent) can not differentiate between the 2 groups. Once you get past 3 pack years, then you can tell the difference (more cancer, more deaths, etc.) For a nonsmoker to get to 3 pack years, he would have to spend 8 hours a day, 5 days a week for FIFTY YEARS in a room blue with smoke. I very much doubt there is even one such person in the US.

Henry W.
Henry W.5 years ago

The hypocrisy of this study. Second hand smoke in China? Just look at the record breaking air pollution levels, then you understand why they need to seek other scapegoats to explain bad health.

Hanine El-Mir
Hanine El Mir5 years ago

Smoking sucks. Wish we could somehow ban it worldwide.

Ana R
ANA MARIJA R5 years ago

Thank you for the article.