Increased consumption of fruits and vegetables may protect against the development of lung cancer, although epidemiologic findings to date are inconclusive. We prospectively examined associations between fruit and vegetable intakes and lung cancer risk in 490,599 men and women, aged 50-71 and cancer-free at enrollment in 1995-1996, in the NIH-AARP Diet and Health Study. At baseline, participants completed a 124-item food frequency questionnaire and provided information on smoking, alcohol consumption, and other factors. A total of 3,922 incident lung cancer cases (2,525 in men and 1,397 in women) were identified during 5 years of follow-up. In multivariate models adjusted for several risk factors, including a variable that integrated smoking status, intensity, and time since quitting, there was a modest reduction in lung cancer risk among men in the highest versus the lowest quintile of total fruit and vegetable consumption (relative risk (RR) = 0.85, 95% confidence interval (CI): 0.74-0.98, p trend = 0.05). When analyzed separately, associations were somewhat weaker for total fruits (RR for highest versus lowest quintile = 0.89, 95% CI: 0.78-1.02) and total vegetables (RR = 0.89, 95% CI: 0.78-1.02). Intakes of fruits and vegetables, as well as total fruits, were inversely associated with lung cancer risk in women, although none of the risk estimates were statistically significant (RR for highest versus lowest quintile of total fruits and vegetables = 0.86, 95% CI: 0.72-1.03, p trend = 0.30). Vegetable consumption was unrelated to lung cancer risk in women. In analyses stratified by histologic type, fruit and vegetable intake appeared to be most protective against squamous cell carcinoma, particularly in women (RR for highest versus lowest quintile of total fruits and vegetables = 0.51, 95% CI: 0.31-0.84, p trend = 0.01). There was no effect modification by smoking status for any fruit and vegetable group. These results indicate that fruit and vegetable consumption may have a modest benefit on lung cancer risk, although residual confounding by smoking could explain these findings. Smoking prevention and cessation remain the most effective means to reduce the burden of this disease.

98th AACR Annual Meeting-- Apr 14-18, 2007; Los Angeles, CA