DIET AND LUNG-CANCER 20- MORE QUESTIONS THAN ANSWERS( YEARS LATER )

A critical review of epidemiological studies on diet and lung cancer o ver the last 20+ years has not provided overwhelming evidence that hig her consumption of vegetables, fruit, low-fat/low-cholesterol foods or such micronutrients as carotenoids, selenium and vitamins A, C or E i s associated with reduced lung cancer risk. Results from case-control studies have been more positive, with about one half showing fruit and vegetables or their associated micronutrients to be associated with r educed risk. However, most results from cohort and serum micronutrient studies, which avoid the problems of inaccurate accounting of diet an d recall bias, were statistically insignificant. Moreover, although mo st studies were conducted on white male smokers in North America and E urope, the few studies which found significant contrary trends were am ong subjects of different backgrounds, i.e., black American males and Chinese women in China. Since male smokers vs. nonsmokers in Europe, N orth America and Japan have been shown in other studies to be lower co nsumers of fruit/vegetables, and less likely to pursue ''perceived hea lthier lifestyles,'' the possibility that some of the epidemiological findings on diet and lung cancer are artifactually due to inadequate a djustment for behavioral correlates of smoking and health seekers in a particular society must be considered, This is especially true with r ecent chemoprevention trials showing higher lung cancer incidence and deaths among consumers of beta-carotene supplements vs. placebo. (C) 1 997 Wiley-Liss, Inc.