Passive smoking 'harms heart'

Second-hand smoke is bad for your heart

Breathing in second-hand smoke for just 30 minutes can temporarily damage your heart, scientists have found.

Researchers at Osaka City University Medical School in Osaka, Japan found passive smoking for half an hour dramatically affected the circulation of blood within the hearts of non-smokers.

Other studies have shown the risk of death from coronary heart disease is increased among non-smokers who are exposed to environmental smoke, by as much as 23%.

Anti-smoking campaigners in the UK are now calling for passive smoking in the workplace to be better controlled.

This provides direct evidence of a harmful effect of passive smoking on the coronary circulation in non-smokers

Research authors

The researchers compared the hearts of 30 Japanese men, half of whom smoked and half of whom did not.

None had a history of high blood pressure, diabetes, or high cholesterol - risk factors for heart problems.

They were checked before and after exposure to second-hand smoke.

Measurements

Scientists, led by Dr Roy Otsuka, took a kind of ultrasound picture of the heart.

They were able to measure coronary flow velocity reserve (CFVR) - which measures how well the endothelial cells that line the cavities of the heart and the blood vessels work.

The cells help widen blood vessels, meaning an increase in blood flow and prevent clots and fatty deposits forming in arteries.

Passive smoking did not affect smokers, but non-smokers saw their CFVR abruptly reduced.

Other tests found non-smokers had higher average CFVR levels than smokers - but after the passive smoking exposure the rates did not differ.

The authors, writing in the Journal of the American Medical Association, said: "This provides direct evidence of a harmful effect of passive smoking on the coronary circulation in non-smokers."

The reduction in endothelial function was not linked to changes in heart rate or blood pressure.

But the researchers said: "This change may be one reason why passive smoking is a risk factor for cardiac disease morbidity and mortality in non-smokers."

'Reduce exposure'

In an editorial accompanying the research, Dr Stanton Glanz and Dr William Parmley of the University of California, San Franciso, wrote: "The findings of the study of Otsuka et al add to the evidence suggesting that everyone should be protected from even short-term exposure to the toxins in second-hand smoke."

Clive Bates, director of Action on Smoking and Health said: "It is as if the blood vessels in the heart react suddenly to small doses of tobacco smoke - almost like an allergic reaction or spasm. This can have the same impact on blood flow as active smoking.

"Passive smoking has a serious impact on the heart and is a real killer, not just a nuisance or irritation."

ASH and the British Heart Foundation are calling on the government to push forward the Code of Practice on passive smoking in the workplace, as promised in its 1998 tobacco White Paper

Professor Sir Charles George, medical director for the BHF, said the government must play a more pro-active role in developing policy that will influence companies, the hospitality industry and those responsible for managing public places, to provide "genuine smoke free environments".

"Until then, people will continue to have little control over the risk to their heart health by having to spend time in 'smokey' atmospheres."