Positive Health Online

Abstract

BRENNAN and colleagues, Unit of Environmental Cancer Epidemiology, International Agency for Research on Cancer, Lyon, France. Brennan@iarc.fr studied the role of dietary patterns and specific dietary nutrients in the aetiology of lung cancer in non-smokers.

Background

Methodology

The authors conducted a multicentre case-control study, in which 506 non-smoking incident lung cancer cases were identified in the 8 centres, along with 1045 non-smoking controls. A quantitative food-frequency questionnaire assessed dietary habits, from which measures of total carotenoids, beta-carotene and retinol nutrient intake were estimated.

Results

Protective effects against lung cancer were found for high consumption of tomatoes (odds ratio (OR) = 0.5), lettuce (OR = 0.6), carrots (OR = 0.8), margarine (OR = 0.7) and cheese (OR = 0.7). Weak protective effects were seen for high consumption of all carotenoids (OR = 0.8), beta-carotene (OR = 0.8) and retinol (OR = 0.9). Protective effects for high levels of fruit consumption were restricted to squamous cell carcinoma (OR = 0.7) and small cell carcinoma (OR = 0.7); these were not apparent for adenocarcinoma (OR = 0.9). Excess risk associated with meat, butter and eggs was restricted to squamous and small cell carcinomas, but not for adenocarcinomas.

Conclusion

This evidence suggests that the public health significance of increasing vegetable consumption among the bottom third of the population would include a reduction in the incidence of lung cancer among lifetime non-smokers by at least 25% and possibly more. A similar protective effect for increased fruit consumption may be present for squamous cell and small cell lung carcinomas.

References

Brennan P et al. A multicenter case-control study of diet and lung cancer among non-smokers. Cancer Causes and Control 11(1): 49-58. Jan 2000.