US researchers have pinpointed a key killer compound in cigarette smoke.
The chemical acrolein - found in tobacco and also some cooking oils - appears to be a prime cause of smoking-related lung cancer and some nonsmoking-related lung cancers as well, according to studies conducted with lung cancer cells.
Acrolein can trigger DNA mutations in cells while reducing the cell's ability to repair that damage, the researchers explained.
Variant that causes cancer
"Cigarettes have a lot of carcinogens, some are more potent and more abundant than others," said lead researcher Moon-shong Tang, from the departments of environmental medicine, pathology and medicine at New York University. "Acrolein is probably the true variant that causes smoking-induced lung cancer."
In fact, Tang's team found acrolein to be 10 000 times more prevalent than another class of carcinogen, called polycyclic aromatic hydrocarbons (PAHs), which had previously been identified as a cause of lung cancer.
The findings were expected to be published Monday in this week's issue of the Proceedings of the National Academy of Sciences.
Acrolein in cooking oil
Tang noted that, in Asian countries, many women who don't smoke still get lung cancer. However, these women cook with oils that are heated to very high temperatures and release high amounts of acrolein. "We think this is related to female lung cancer," Tang said.
"Now we know the cause of smoking and nonsmoking lung cancer," Tang said.
The New York City researcher believes the finding has implications for preventing lung cancer and assessing the lung cancer risk of various populations.
If acrolein were removed from cigarettes, he speculated, they would be less likely to cause lung malignancies.
More factors at work
However, another expert believes that many other carcinogens in cigarette smoke contribute to cancer risk.
"It is not simple to conclude that any one carcinogen in cigarette smoke is necessarily responsible for lung cancer. It would be a mistake to do that," said Stephen S. Hecht, the Wallin Professor of Cancer Prevention at the Cancer Centre and the Department of Laboratory Medicine and Pathology at the University of Minnesota and author of an accompanying commentary.
Hecht believes the notion of a "cancer-safe" cigarette is misguided.
"If people got the impression that by removing or reducing any one carcinogen from cigarette smoke that you could therefore produce a safe product with respect to lung cancer, that would be wrong," he said. – (HealthDayNews)
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