A PROSPECTIVE COHORT STUDY ON ALLIUM VEGETABLE CONSUMPTION, GARLIC SUPPLEMENT USE, AND THE RISK OF LUNG-CARCINOMA IN THE NETHERLANDS

The association between the consumption of onions and leeks (vegetable s belonging to the Allium genus), garlic supplements, and the risk of lung carcinoma was investigated in a large-scale prospective cohort st udy on diet and cancer in the Netherlands. The Netherlands Cohort Stud y was started in 1986 among 120,852 men and women, ages 55-69 years, b y collecting information on usual diet and important life-style charac teristics. After 3.3 years of follow-up, 550 incident lung carcinoma c ases mere observed. Information on Allium vegetable consumption was av ailable for 484 lung carcinoma cases and 3123 members of a randomly sa mpled subcohort. In stratified analysis, a lower lung carcinoma risk w as observed in the highest onion intake category [rate ratio (RR) = 0. 65; 95% confidence interval, 0.45-0.95] compared to the lowest consump tion category. After including other, dietary and nondietary, determin ants of lung carcinoma in the multivariable models and using pack year s for past and current smoking, instead of using smoking status catego rized as never, ex-, and current smoking, the rate ratio in the highes t intake category increased to 0.80 and was no longer significantly di fferent from unity (95% confidence interval, 0.52-1.24). Leek consumpt ion was not associated with risk for lung carcinoma (RR = 1.08; 95% co nfidence interval 0.80-1.45 in the highest intake category, compared t o the lowest). No statistically significant trends in the rate ratios associated with increasing consumption of these vegetables were detect ed for lung carcinoma or the four histological subtypes. A higher lung carcinoma risk was observed for those subjects who used exclusively g arlic supplements (RR = 1.78; 95% confidence interval, 1.08-2.92), com pared to those not taking dietary supplements. A lower lung carcinoma risk was seen for those using garlic supplements together with any oth er supplement (RR = 0.93; 95% confidence interval 0.46-1.86) compared to those using any other supplement. In conclusion, we found no eviden ce of a relation between the consumption of onions or leeks and the ri sk of lung carcinoma or any of the histological subtypes. Garlic suppl ement use seems not associated with a lower risk of lung carcinoma.