Gao C M, Tajima K, Kuroishi T, Hirose K, Inoue M
Jiangsu Institute of Cancer Research, Beiziting, Nanjing, China.
Jpn J Cancer Res. 1993 Jun;84(6):594-600. doi: 10.1111/j.1349-7006.1993.tb02018.x.
In a hospital-based case control study, the protecting effects of fruit, raw and green vegetables against lung cancer risk among male smokers were studied in 282 cases and the same number of controls. The current smokers showed a 6.61-fold increased risk of lung cancer. The odds ratio (OR) declined markedly with starting age of smoking habit and increased markedly with number of cigarettes smoked per day. The ex-smokers showed a 3.56-fold increased risk of lung cancer. The ORs gradually decreased with years passed since cessation of smoking. In the single factor analysis, significant protective effects of fruit, raw vegetables, green vegetables, lettuce and cabbage against lung cancer were found. The risk for all lung cancer decreased to 0.45 (95% confidence intervals (CI) 0.30-0.67), 0.64 (95% CI 0.43-0.97) and 0.44 (95% CI 0.26-0.73) with increment of intake frequency of fruit, raw and green vegetables respectively. The OR for lung cancer decreased to 0.41 (95% CI 0.24-0.72) and 0.56 (95% CI 0.32-0.99) with increasing intake frequency of fruit and raw vegetables among current smoking males. Lettuce and cabbage showed protective effects against lung cancer, and the OR for risk of lung cancer decreased to one-half among the high intake frequency group. The risk of lung cancer among current smokers declined markedly with increasing intake of lettuce and cabbage. A similar effect was observed among ex-smokers and non-smokers, but there was no statistical significance. In the multivariate analysis, fruit and raw vegetables showed the strongest protective effects against lung cancer among current smokers (P = 0.01). Among ex-smokers, the protective effect of fruit is also statistically significant (P = 0.03). These results suggest that fruit and raw vegetables may play an important role in protecting smokers from lung cancer.
在一项基于医院的病例对照研究中，对282例男性吸烟者及相同数量的对照者，研究了水果、生蔬菜和绿色蔬菜对肺癌风险的保护作用。当前吸烟者患肺癌的风险增加了6.61倍。优势比（OR）随着吸烟习惯开始年龄的增加而显著下降，随着每天吸烟量的增加而显著上升。既往吸烟者患肺癌的风险增加了3.56倍。OR随着戒烟时间的推移而逐渐降低。在单因素分析中，发现水果、生蔬菜、绿色蔬菜、生菜和卷心菜对肺癌有显著的保护作用。随着水果、生蔬菜和绿色蔬菜摄入频率的增加，所有肺癌的风险分别降至0.45（95%置信区间（CI）0.30 - 0.67）、0.64（95%CI 0.43 - 0.97）和0.44（95%CI 0.26 - 0.73）。在当前吸烟男性中，随着水果和生蔬菜摄入频率的增加，肺癌的OR降至0.41（95%CI 0.24 - 0.72）和0.56（95%CI 0.32 - 0.99）。生菜和卷心菜对肺癌有保护作用，在高摄入频率组中，肺癌风险的OR降至一半。当前吸烟者中肺癌的风险随着生菜和卷心菜摄入量的增加而显著下降。在既往吸烟者和非吸烟者中也观察到类似的效果，但无统计学意义。在多因素分析中，水果和生蔬菜对当前吸烟者的肺癌具有最强的保护作用（P = 0.01）。在既往吸烟者中，水果的保护作用也具有统计学意义（P = 0.03）。这些结果表明，水果和生蔬菜可能在保护吸烟者免受肺癌侵害方面发挥重要作用。
