Jeder Kontakt zu Tabakrauch erhöht das Herzinfarktrisiko

Eine weltweit in 52 Ländern durchgeführte Studie erbrachte den Beweis dafür, daß jeder Kontakt mit Tabakrauch das Risiko für Herzinfarkte stark erhöht. Das gilt beispielsweise auch für die Nutzung von Wasserpfeifen sowie für Passivrauchen. Die Wissenschaftler konnten beweisen, daß das Herzinfarktrisiko direkt abhängig ist von der Zahl der täglich gerauchten Zigaretten. Jede gerauchte Zigarette erhöht danach das Herzinfarktrisiko um 5.6%.

Die im Fachblatt The Lancet veröffentlichte Untersuchung zeigt aber auch, daß es sich in jedem Alter lohnt mit dem Rauchen aufzuhören. Bei  Rauchern die  pro Tag nur wenige Zigaretten geraucht haben, ist das erhöhte Herzinfarktrisiko bereits wenige Jahre nach dem Rauchstop wieder normal.

All tobacco exposure raises heart attack risk

A global study led by two Canadian researchers has shown evidence that all tobacco exposure -- chewing, smoking or second-hand smoke -- can lead to an increased risk of heart attack.

Dr. Koon Teo, one of the authors, says because of the magnitude of the study, he and colleagues from around the world were able to confirm a lot of assumptions and suspicions about the effect tobacco has on cardiovascular health.

"(With this study) we included practically all the regions of the world," he said in an interview Thursday. "So we can say that the results apply to all ... different types of people."

The study, published in the Lancet, was led by Teo and Dr. Salim Yusuf of McMaster University in Hamilton, Ont., and includes data from over 27,000 people in 52 countries.

The study shows the risk of acute myocardial infarction (AMI) or a heart attack was increased by exposure to tobacco in all forms - including chewing tobacco and second hand smoke.

The study also found an increased risk in those who smoke beedies -- a small amount of tobacco wrapped in a dried temburini leaf smoked in South Asia -- and sheesha, a water pipe, as well as other forms of smoked and non-smoked tobacco used around the world.

Teo said the results of the study are very important for developing countries because most of the tobacco studies to date have been based in Western nations, and 82 per cent of the world's smokers live in the developing world and don't feel the health warnings apply to them.

"(For example) the sheesha, that people smoke in the Middle East mostly, they feel that ... through water, it filters out the toxins," said Teo. "But we found sheesha was just as bad in causing heart attacks."

But the results should not just apply to developing nations, Teo said.

One result he said he cites to his patients in Canada is that once a smoker quits, their risk of a heart attack decreases steadily over time, depending on how many cigarettes a person smoked per day.

"For people who smoke lighter, maybe up to 10 cigarettes a day, after five years the risk is almost gone," said Teo.

"The risk they are suffering actually diminishes very quickly so it's never too late to quit."

Colleen Norris, an epidemiologist and associate professor at the University of Alberta, said the study is "really outstanding work."

Norris -- a population health scholar in cardiovascular disease with the Alberta Heritage Foundation for Medical Research - said the current research on smoking and cardiovascular health points to smoking as one cause of heart problems, among many others.

"What's unique about this study, is it's taking away all the other (risks associated with heart attacks) and saying just by itself, this is what smoking is contributing," she said from Edmonton.

The discussion portion of the study states "the effect of tobacco use on AMI risk was consistent in the presence and absence of the other risk factors."

The study was funded by the Canadian Institute of Health Research, the Heart and Stroke Foundation of Ontario and the International Clinical Epidemiology Network. It also received support from various pharmaceutical companies and organizations around the world.

The study also found that risk level was related to the number of cigarettes smoked -- increasing 5.6 per cent for each cigarette smoked per day.

Teo said he hopes the results of this study will help in developing nations, which he says are going through what North America went through in the 1950s - when a much higher percentage of the population smoked.

"If we can do something about getting people to quit or not start, then hopefully they'll avoid that harm that Western countries suffered about 50 years ago," he said.