A preliminary study of women in China suggests that prolonged exposure to smoky fumes from cooking oils may be an important cause of lung cancer, a researcher said last week.
The finding helps explain the relatively high rate of lung cancer among Chinese women who do not smoke, said William Blot, chief of the biostatistics branch at the National Cancer Institute.
"One of the reasons Chinese women have higher lung cancer rates may be the exposure to these fumes," Blot said in an interview.
The incidence of lung cancer was highest among women who more frequently prepared meals by stir-frying their food at very high temperatures that tended to vaporize cooking oils, Blot said.
The lung cancer risk was also associated with the use of rapeseed oil, which is widely used in China and is only now becoming available in the United States, he said.
Blot emphasized that rapeseed oil itself is not harmful and that the findings are too preliminary for him to recommend that people in China or elsewhere change their cooking habits.
Blot described his findings at the annual scientific meeting of the General Motors Cancer Research Foundation Assembly, a group of senior scientists involved in various aspects of cancer research.
He also reported the results of another Chinese study suggesting that people who consume a diet rich in fresh vegetables such as Chinese cabbage and other greens have a lower risk of developing stomach cancer.
The studies are part of a series of collaborations between Chinese and American researchers. The aim of the project is to better determine the role that environmental factors, such as diet and industrial chemicals, play in the development of cancer, Blot said.
The National Cancer Institute, the principal American agency working with the Chinese, is spending some $700,000 annually for these studies.