Inhaling second-hand smoke could increase the risk of developing severe dementia later in life, a study has found.

Passive smoking has been linked to cardio and respiratory diseases before, but this study, published in the BMJ Occupational and Environmental Medicine, is the first to connect environmental tabacco smoke (ETS) exposure to dementia.


The study assessed the dementia syndromes and ETS of 6,000 people aged 60 or above in China between 2001 and 2007, and again in 2007 and 2008.

The findings showed that 626 participants (10.6%) had severe dementia syndromes and 869 (14.7%) had moderate syndromes.

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Passive smoking could lead to severe dementia

The results revealed a significant association between ETS exposure and severe dementia syndromes was found. The relationship is dose-independent, and ETS significantly affects never smokers and former/current smokers.

In 2012 numerous studies into the possible causes of dementia have lead to suggested lifestyle changes to help prevent the disease. These include removing visual clutter and eating a daily dose of chocolate.

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  • Struggling to remember recent events, although they can easily recall things that happened in the past

  • Repeating themselves or losing the thread of what they are saying

  • Forgetting the names of friends or everyday objects

  • Feeling confused even when in a familiar environment

  • Having problems thinking and reasoning

  • Feeling anxious, depressed or angry about their memory loss

  • Finding that other people start to comment on their memory loss

  • Having difficulty recalling things they have heard, seen or read

  • Finding it hard to follow conversations or programmes on TV