Amanda Cross and colleagues at the National Cancer Institute analyzed data on diet and health from a U.S. database of about 500,000 men and women ages 50 to 71, which began in 1995 -- none of whom had had cancer previously. They found one in 10 lung cancers could be avoided if people reduced their red and processed meat intake.

People whose red meat intake was in the top one-fifth of the range of consumption had an increased risk of developing colorectal, liver, lung and esophageal cancer when compared to people in the lowest one-fifth of consumption.

The study, published in PLoS Medicine, also found that individuals in the highest one-fifth of processed meat intake had a 20 percent elevated risk for colorectal and a 16 percent elevated risk for lung cancer.

However, exactly which type of meat is related to cancer remains unclear -- the study's definitions of red meat and processed meat overlapped, for example, bacon and ham were included in both categories and most of the study participants were non-Hispanic white, so the findings may not apply to people with different genetic backgrounds.