Related Experiment Video
Updated: Jul 2, 2026

A Protocol for Detecting and Scavenging Gas-phase Free Radicals in Mainstream Cigarette Smoke
Published on: January 2, 2012
Green tea consumption and lung cancer risk: the Ohsaki study
1Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan. liqiangda@yahoo.com.cn
Abstract:
We examined the risk of lung cancer in relation to green tea consumption in a population-based cohort study in Japan among 41,440 men and women, aged 40-79 years, who completed a questionnaire in 1994 regarding green tea consumption and other health-related lifestyle factors. During the follow-up period of 7 years (from 1995 to 2001), 302 cases of lung cancer were identified, and the Cox proportional hazards regression model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). The multivariable-adjusted HRs of lung cancer incidence for green tea consumption of 1 or 2, 3 or 4, and 5 or more cups/day as compared to less than 1 cup/day were 1.14 (95% CI: 0.80-1.62), 1.18 (95% CI: 0.83-1.66), and 1.17 (95% CI: 0.85-1.61), respectively (P for trend=0.48). This cohort study has found no evidence that green tea consumption is associated with lung cancer.
Related Concept Videos
Cancer Prevention
Some...
Statistical Methods for Analyzing Epidemiological Data
Observational Studies
There are three types of observational studies – Prospective, retrospective, and cross-sectional.
Prospective Study
Prospective studies, also known as longitudinal or cohort studies, are carried out by collecting future data from groups sharing similar characteristics. One example of...