Tea consumption and Papillary Thyroid Cancer Risk: a Case-Control Study of Adults in Shanghai, China

Abstract

Abstract Few studies have explored the impact of consumption of three types of tea on the risk for papillary thyroid cancer (PTC) in East Asia. A case-control study was conducted with323 Chinese patients with histological confirmed differentiated thyroid cancer and 323 healthy subjects selected from the same hospital. Participants were matched by age, nationality and gender, and interviewed face-to-face by trained interviewers using a structured questionnaire. Participants who drank tea at least once a day (p = 0.023) or consumed ≤ five grams each time (p = 0.047) had a lower PTC risk than unfermented tea non-drinkers had. Participants who drank tea at least once a month but < once a day (p = 0.023) or consumed ≤ five grams each time (p = 0.018) had a lower PTC risk than did semi-fermented tea non-drinkers. Among females, a significantly lower PTC risk was found in those who drank unfermented tea at least once a day (p = 0.030) compared with the unfermented tea non-drinkers. No dose-response relationship of the ever-drinkers’ three tea types was found between the amount of tea consumed each time and a lower PTC risk among all participants. Consuming unfermented tea at least once a day was the most protective factor in lowering PTC risk among females.