WASHINGTON?Eating a variety of fruits and vegetables may decrease the risk of some kinds of lung cancer for smokers, according to a study released Monday.

"Although quitting smoking is the most important preventive action in reducing lung cancer risk, consuming a mix of different types of fruit and vegetables may also reduce risk, independent of the amount, especially among smokers," said H. Bas Bueno-de-Mesquita of the Netherlands-based National Institute for Public Health and the Environment.

The study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, was based on research involving more than 450,000 people in Europe, including 1,600 who were diagnosed with lung cancer.

The researchers said the variety of fruits and vegetables appeared to be more important than the quantity. They studied 14 commonly eaten fruits and 26 vegetables including fresh, canned or dried products.

"Fruits and vegetables contain many different bioactive compounds, and it makes sense to assume that it is important that you not only eat the recommended amounts, but also consume a rich mix of these bioactive compounds by consuming a large variety," Bueno-de-Mesquita said.

The risk of squamous cell carcinoma decreased substantially when a variety of fruits and vegetables were eaten, the study concluded.

While previous research has shown the influence of the quantity of fruits and vegetables on cancer development, Stephen Hecht, editorial board member for Cancer Epidemiology, Biomarkers & Prevention, said this is one of the first to evaluate diversity of fruit and vegetable consumption, rather than quantity.

"The results are very interesting and demonstrate a protective effect in smokers," he said.

"There are still over a billion smokers in the world, and many are addicted to nicotine and cannot stop in spite of their best efforts," said Hecht, who is a faculty member at the University of Minnesota.

Hecht said that tobacco smoke contains a complex mixture of cancer-causing agents and that a mixture of protective agents is needed to have any beneficial effect in reducing the risk of lung cancer.

"Nevertheless, the public should be made aware and be reminded that the only proven way to reduce your risk for lung cancer is to avoid tobacco in all its forms," he said.