Fruits, vegetables and lung cancer: a pooled analysis of cohort studies.
Inverse associations between fruit and vegetable consumption and lung cancer risk have been consistently reported. However, identifying the specific fruits and vegetables associated with lung cancer is difficult because the food groups and foods evaluated have varied across studies. We analyzed fruit and vegetable groups using standardized exposure and covariate definitions in 8 prospective studies. We combined study-specific relative risks (RRs) using a random effects model. In the pooled database, 3,206 incident lung cancer cases occurred among 430,281 women and men followed for up to 6-16 years across studies. Controlling for smoking habits and other lung cancer risk factors, a 16-23% reduction in lung cancer risk was observed for quintiles 2 through 5 vs. the lowest quintile of consumption for total fruits (RR = 0.77; 95% CI = 0.67-0.87 for quintile 5; p-value, test for trend < 0.001) and for total fruits and vegetables (RR = 0.79; 95% CI = 0.69-0.90; p-value, test for trend = 0.001). For the same comparison, the association was weaker for total vegetable consumption (RR = 0.88; 95% CI = 0.78-1.00; p-value, test for trend = 0.12). Associations were similar between never, past, and current smokers. These results suggest that elevated fruit and vegetable consumption is associated with a modest reduction in lung cancer risk, which is mostly attributable to fruit, not vegetable, intake. However, we cannot rule out the possibility that our results are due to residual confounding by smoking. The primary focus for reducing lung cancer incidence should continue to be smoking prevention and cessation.
Smith-Warner
Stephanie A
SA
Department of Nutrition, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA.
Spiegelman
Donna
D
Yaun
Shiaw-Shyuan
SS
Albanes
Demetrius
D
Beeson
W Lawrence
WL
van den Brandt
Piet A
PA
Feskanich
Diane
D
Folsom
Aaron R
AR
Fraser
Gary E
GE
Freudenheim
Jo L
JL
Giovannucci
Edward
E
Goldbohm
R Alexandra
RA
Graham
Saxon
S
Kushi
Lawrence H
LH
Miller
Anthony B
AB
Pietinen
Pirjo
P
Rohan
Thomas E
TE
Speizer
Frank E
FE
Willett
Walter C
WC
Hunter
David J
DJ
D000704:Analysis of Variance; D015331:Cohort Studies; D005260:Female; D005638:Fruit; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000517:prevention & control; D008297:Male; D015203:Reproducibility of Results; D012306:Risk; D012307:Risk Factors; D018401:Sample Size; D012907:Smoking; D014675:Vegetables