LOS ANGELES, CA (Catholic Online) - Conducted by scientists from Anhui Medical University in China and King's College London, a recently examined nearly 6,000 people aged over 60 from five provinces in China.

The participants were examined for dementia syndromes between 2001 and 2003 and again in 2007 and 2008 as well as their exposure to second-hand smoke.

They found that 10 per cent of the group had severe dementia syndromes. This was significantly related to exposure level and duration of passive smoking. The associations with severe syndromes were found in people who had never smoked and in former and current smokers.

"Passive smoking should be considered an important risk factor for severe dementia syndromes, as this study in China shows," study leader Dr Ruoling Chen, from King's College said:

"Avoiding exposure to ETS (environmental tobacco smoker) may reduce the risk of severe dementia syndromes."

A newly emerging economic powerhouse, China is the largest consumer of tobacco in the world, with 350 million smokers. The Chinese government since 2006 has actively promoted the introduction of smoke-free environments in hospitals, schools, on public transport and in other public places. Implementation has not been widespread.

China also has the highest number of dementia sufferers in the world, with increasing rates of new cases as the population ages. "The increased risk of severe dementia syndromes in those exposed to passive smoking is similar to increased risk of coronary heart disease," Dr. Chen says.

"At present, we know that about 90 percent of the world's population lives in countries without smoke-free public areas.

"More campaigns against tobacco exposure in the general population will help decrease the risk of severe dementia syndromes and reduce the dementia epidemic worldwide."

According to the World Health Organization (WHO), nearly 80 percent of the more than one billion smokers worldwide live in low- and middle-income countries, where the burden of tobacco-related illness and death is heaviest.

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