To investigate whether green tea consumption has an etiological association with prostate cancer, a case-control study was conducted in Hangzhou, southeast China during 2001-2002. The cases were 130 incident patients with histologically confirmed adenocarcinoma of the prostate. The controls were 274 hospital inpatients without prostate cancer or any other malignant diseases, and matched to the age of cases. Information on duration, quantity and frequency of usual tea consumption, as well as the number of new batches brewed per day, were collected by face-to-face interview using a structured questionnaire. The risk of prostate cancer for tea consumption was assessed using multivariate logistic regression adjusting for age, locality, education, income, body mass index, physical activity, alcohol consumption, tobacco smoking, total fat intake, marital status, age at marriage, number of children, history of vasectomy and family history of prostate cancer. Among the cases, 55.4% were tea drinkers compared to 79.9% for the controls. Almost all the tea consumed was green tea. The prostate cancer risk declined with increasing frequency, duration and quantity of green tea consumption. The adjusted odds ratio (OR), relative to non-tea drinkers, were 0.28 (95% CI ‫؍‬ 0.17-0.47) for tea drinking, 0.12 (95% CI ‫؍‬ 0.06 -0.26) for drinking tea over 40 years, 0.09 (95% CI ‫؍‬ 0.04 -0.21) for those consuming more than 1.5 kg of tea leaves yearly, and 0.27 (95% CI ‫؍‬ 0.15-0.48) for those drinking more than 3 cups (1 litre) daily. The dose response relationships were also significant, suggesting that green tea is protective against prostate cancer.

To determine whether dietary intake of lycopene and other carotenoids has an etiological association with prostate cancer, a casecontrol study was conducted in Hangzhou, southeast China during 2001-2002. The cases were 130 incident patients with histologically confirmed adenocarcinoma of the prostate. The controls were 274 hospital inpatients without prostate cancer or any other malignant diseases. Information on usual food consumption, including vegetables and fruits, was collected by face-to-face interviews using a structured food frequency questionnaire. The risks of prostate cancer for the intake of carotenoids and selected vegetables and fruits rich in carotenoids were assessed using multivariate logistic regression, adjusting for age, locality, education, income, body mass index, marital status, number of children, family history of prostate cancer, tea drinking, total fat and caloric intake. The prostate cancer risk declined with increasing consumption of lycopene, ␣-carotene, ␤-carotene, ␤-cryptoxanthin, lutein and zeaxanthin. Intake of tomatoes, pumpkin, spinach, watermelon and citrus fruits were also inversely associated with the prostate cancer risk Key words: case-control study; lycopene; carotenoids; prostate cancer; China Prostate cancer is the most common noncutaneous cancer among men in developed countries. It is also the second leading cause of death from malignancies. 1,2 Epidemiological studies have documented the dramatic variations in prostate cancer incidence and mortality across geographic regions, as well as the changes in incidence and mortality among migrant populations, 2-5 leading to the recent interest in nutrition and dietary intake risk factors. There is compelling epidemiological evidence suggesting that a diverse diet, rich in fruits and vegetables, can reduce the risk of cancer. 3 In particular, several studies have revealed the beneficial effects of the tomato and its products, a major source of dietary carotenoids including lycopene, against prostate cancer, 6 -10 although conflicting evidence has also been reported. [11][12][13][14] It should be noted that previous epidemiologic investigations were mainly conducted in Western countries with particular emphasis on lycopene. There is a lack of evidence from Asian countries, where the incidence of prostate cancer is low and the dietary patterns are different from those of Western countries. To determine whether dietary intake of lycopene and other carotenoids has an association with prostate cancer among Chinese men, we conducted a case-control study in Hangzhou (population 4.5 million), the capital of Zhejiang Province, in southeast China. Material and methods Study populationBetween July 2001 and June 2002, prostate cancer cases were identified by daily searches of all new inpatient records and pathology reports in the urology wards of the 8 public hospitals in Hangzhou. Inclusion criteria for cases were defined to be men over 45 years of age with a confirmed histopathological report of adenocarcinoma of the prostate, who had ...

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