Passive smoking on HWN FAN COLUMN

Passive smoking can increase the risk of suffering a stroke by 30 per cent, according to new research.

Scientists identified a clear trend between second-hand smoke and strokes following a study involving 22,000 people over the age of 45.

They found that even after adjustment for other stroke factors such as hypertension and heart disease, the 30 per cent risk remained.

Nearly one in four of the participants (23 per cent) had been effected by second-hand smoke in the last last twelve months.

During the period of April 2003 to March 2012, 428 strokes were reported.

A further analysis of the type of stroke was performed and showed that most strokes were due to blockage of blood flow to the brain.

The study, published in the American Journal of Preventative Medicine, will join a growing body of work into the potential effects of secondhand smoke

Lead author Doctor Angela Malek, of the Medical University of South Carolina, said: 'Previous studies suffer from limitations in that few were prospective, adjustment for potential confounders has varied, stroke and SHS exposure have not been consistently defined, measurement and sources of SHS exposure have differed, stroke sub-types have not always been assessed, and some studies have been underpowered due to small sample size.

Our findings suggest the possibility for adverse health outcomes such as stroke among nonsmokers exposed to SHS and add to the body of evidence supporting stricter smoking regulations.

Future research will need to investigate the role of cardiovascular disease risk factors in the association and explore potential exposure to additional environmental variables, such as ambient air pollutants, in relation to stroke.