Table 3

Pooled multivariate relative risks (95% confidence intervals) of lung cancer for quartiles of dietary carotenoids by smoking statusa

CarotenoidQuartile 1Quartile 2Quartile 3Quartile 4P
Test for trendTest for between study heterogeneity for quartile 4Test for between study heterogeneity due to smoking status for quartile 4
α-Carotene
 Current smokersb,c1.000.99 (0.87–1.13)1.08 (0.94–1.23)0.99 (0.85–1.15)0.970.45
 Past smokersb,d,e1.000.90 (0.74–1.11)0.96 (0.78–1.19)0.94 (0.72–1.23)0.440.15
 Never smokersb,e1.000.77 (0.52–1.13)0.95 (0.66–1.36)0.92 (0.64–1.33)0.820.470.88
β-Carotene
 Current smokersb,c1.001.01 (0.85–1.20)0.98 (0.85–1.13)0.98 (0.84–1.14)0.620.89
 Past smokersb,d,e1.000.88 (0.71–1.07)0.86 (0.70–1.05)1.06 (0.86–1.32)0.610.35
 Never smokersb,e1.001.11 (0.76–1.62)0.98 (0.67–1.44)1.02 (0.70–1.47)0.730.800.83
β-Cryptoxanthin
 Current smokersb,c1.000.84 (0.74–0.96)0.87 (0.75–1.01)0.70 (0.60–0.81)<0.0010.47
 Past smokersb,d,e1.000.80 (0.64–1.00)0.93 (0.73–1.18)0.84 (0.69–1.03)0.430.45
 Never smokersb,e1.000.74 (0.43–1.28)0.79 (0.45–1.37)0.77 (0.42–1.42)0.800.020.30
Lutein/zeaxanthin
 Current smokersb,c1.001.00 (0.87–1.15)0.95 (0.83–1.09)0.91 (0.79–1.05)0.080.92
 Past smokersb,d,e1.001.05 (0.80–1.38)0.99 (0.78–1.27)1.03 (0.84–1.26)0.690.51
 Never smokersb,e1.000.87 (0.60–1.28)0.94 (0.66–1.35)0.88 (0.61–1.26)0.750.820.52
Lycopene
 Current smokersb,c1.000.79 (0.68–0.93)0.85 (0.74–0.98)0.81 (0.70–0.94)0.060.65
 Past smokersb,d,e1.000.89 (0.68–1.15)0.82 (0.65–1.05)1.05 (0.86–1.27)0.760.42
 Never smokersb,e1.000.80 (0.55–1.17)0.90 (0.63–1.29)0.86 (0.60–1.23)0.290.680.11
  • a Number of lung cancer cases were as follows: 1915 current smokers, 981 past smokers, and 259 never smokers.

  • b Adjusted for education (<high school graduate, high school graduate, and >high school graduate), body mass index (<23, 23 to <25, 25 to <30, and ≥30 kg/m2), alcohol consumption (0, >0 to <5, 5 to <15, 15 to <30, and ≥30 g/day), energy (continuous).

  • c Also adjusted for smoking duration (continuous) and amount smoked (continuous).

  • d Also adjusted for smoking duration (continuous).

  • e The α-Tocopherol, β-Carotene Cancer Prevention Study was excluded because the cohort included only current smokers.