Diet and lung cancer risk: findings from the Western New York Diet Study.

This study compares the diets of 450 lung cancer cases (296 males, 154 females) with those of 902 controls (587 males, 315 females). Cases were lung cancer patients diagnosed between August 1980 and July 1984 in three western New York counties, while controls were selected from the general population of these same counties. Usual diet was estimated by detailed interviews using a modified food frequency method. Case-control comparisons were made for dietary fat, protein, fiber, calories, cholesterol, and vitamins A, C, and E according to quartiles of intake, adjusting for age and pack-years of cigarettes by multiple logistic regression. Risk was lower for males in the lowest quartile of total dietary fat intake compared with those in the highest quartile (relative risk = 0.5), although the overall trend in the association with dietary fat was not statistically significant (p = 0.12). Likewise, there was a weak, but not statistically significant, direct association between dietary cholesterol and lung cancer in men (p = 0.17). The intake of vitamin A from fruits and vegetables (carotene) was much more strongly associated with reduced cancer risk. For males, the relative risks by quartiles (lowest intake to highest intake) were 1.8, 1.8, 1.0, 1.0 (p for trend = 0.001). For females, this relation was considerably weaker, and was not statistically significant. These findings are generally in agreement with those of several previous studies. The risk reduction associated with vitamin A from fruits and vegetables (carotene) was most evident for males, for those with squamous cell cancers, for light or ex-smokers, and for those over 60 years of age.