Many studies have reported inverse associations between vegetable and fruit
consumption and lung cancer risk. The aim of the present study was to eluc
idate the role of several antioxidants and folate in this relationship. In
the Netherlands Cohort Study on Diet and Cancer, 58,279 men of ages 55-69 S
ears at baseline in 1986 returned a questionnaire including a 150-item food
frequency questionnaire. After 6.3 years of follow-up, 939 male lung cance
r cases were registered. A new Dutch carotenoid database was used to estima
te intake of alpha-carotene, beta-carotene, lutein + zeaxanthin, beta-crypt
oxanthin, and lycopene, completed with the antioxidant vitamins C and E and
folate. Using case-cohort analysis, rate ratios were calculated, adjusted
for age, smoking, educational level, and family history of lung cancer. Pro
tective effects on lung cancer incidence were found for lutein + zeaxanthin
, beta-cryptoxanthin, folate, and vitamin C. Other carotenoids (alpha-carot
ene, beta-carotene, and lycopene) and vitamin E did not show significant as
sociations. After adjustment for vitamin C, only folate remained inversely
associated, and after adjustment for folate, only beta-cryptoxanthin and vi
tamin C remained significantly associated. Inverse associations were strong
est among current smokers and weaker for former smokers at baseline. Invers
e associations with carotenes, lutein C zeaxanthin, and beta-cryptoxanthin
seemed to be limited to small cell and squamous cell carcinomas. Only folat
e and vitamin C intake appeared to be inversely related to small cell and s
quamous cell carcinomas and adenocarcinomas. Folate, vitamin C, and beta-cr
yptoxanthin might be better protective agents against lung cancer in smoker
s than alpha-carotene, beta-carotene, lutein + zeaxanthin, and lycopene.