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.
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