Cumulative consumption of tea is associated with lower risk of liver cancer: Updated results from the Shanghai Women's Health Study.

Prospective epidemiological studies have provided limited evidence for an association between tea consumption and liver cancer risk. Based on a population-based prospective cohort study in middle-aged Chinese women, we investigated the association between tea consumption and the risk of primary liver cancer. Detailed information on tea drinking habits and other potential confounders was obtained at the baseline interview. Incident liver cancer cases were identified through record linkage with the population-based cancer registry and verified through home visits and review of medical charts by medical experts. Multiple aspects of tea drinking habits including starting age, duration, intensity and cumulative consumption of any type of tea and green tea were considered. Multivariable-adjusted hazard ratios (aHRs) and their 95% confidence intervals (CIs) were derived from the Cox regression models. After a median follow-up time of 18.12 (interquartile range = 1.59) years, 253 incident liver cancer cases were identified from 71 841 cohort members. Compared with never tea drinkers, the risk of liver cancer for participants who have consumed over 30 kg of dried tea leaves cumulatively was 0.56 (95% CI: 0.32-0.97). For those who drank green tea only, the aHR was 0.54 (95% CI: 0.30-0.98). This updated study suggested an inverse association between cumulative consumption of tea, especially green tea and the risk of primary liver cancer.

Tea Drinking and Risk of Cancer Incidence: A Meta-Analysis of Prospective Cohort Studies and Evidence Evaluation.

Here we provide a comprehensive meta-analysis to summarize and appraise the quality of the current evidence on the associations of tea drinking in relation to cancer risk. PubMed, Embase, and the Cochrane Database of Systematic Reviews were searched up to June 2020. We reanalyzed the individual prospective studies focused on associations between tea drinking and cancer risk in humans. We conducted a meta-analysis of prospective studies and provided the highest- versus lowest-category analyses, dose-response analyses, and test of nonlinearity of each association by modeling restricted cubic spline regression for each type of tea. We graded the evidence based on the summary effect size, its 95% confidence interval, 95% prediction interval, the extent of heterogeneity, evidence of small-study effects, and excess significance bias. We identified 113 individual studies investigating the associations between tea drinking and 26 cancer sites including 153,598 cancer cases. We assessed 12 associations for the intake of black tea with cancer risk and 26 associations each for the intake of green tea and total tea with cancer risk. Except for an association between lymphoid neoplasms with green tea, we did not find consistent associations for the highest versus lowest categories and dose-response analyses for any cancer. When grading current evidence for each association (number of studies ≥2), weak evidence was detected for lymphoid neoplasm (green tea), glioma (total tea, per 1 cup), bladder cancer (total tea, per 1 cup), and gastric and esophageal cancer (tea, per 1 cup). This review of prospective studies provides little evidence to support the hypothesis that tea drinking is associated with cancer risk. More well-designed studies are still needed to identify associations between tea intake and rare cancers.

Coffee drinking and cancer risk: an umbrella review of meta-analyses of observational studies.

BACKGROUND: Epidemiological studies on the association between coffee intake and cancer risk have yielded inconsistent results. To summarize and appraise the quality of the current evidence, we conducted an umbrella review of existing findings from meta-analyses of observational studies. METHODS: We searched PubMed, Embase, Web of Science and the Cochrane database to obtain systematic reviews and meta-analyses of associations between coffee intake and cancer incidence. For each association, we estimated the summary effect size using the fixed- and random-effects model, the 95% confidence interval, and the 95% prediction interval. We also assessed heterogeneity, evidence of small-study effects, and excess significance bias. RESULTS: Twenty-eight individual meta-analyses including 36 summary associations for 26 cancer sites were retrieved for this umbrella review. A total of 17 meta-analyses were significant at P ≤ 0.05 in the random-effects model. For the highest versus lowest categories, 4 of 26 associations had a more stringent P value (P ≤ 10- 6). Associations for five cancers were significant in dose-response analyses. Most studies (69%) showed low heterogeneity (I2 ≤ 50%). Three and six associations had evidence of excessive significance bias and publication bias, respectively. Coffee intake was inversely related to the risk of liver cancer and endometrial cancer and was characterized by dose-response relationships. There were no substantial changes when we restricted analyses to meta-analysis of cohort studies. CONCLUSIONS: There is highly suggestive evidence for an inverse association between coffee intake and risk of liver and endometrial cancer. Further research is needed to provide more robust evidence for cancer at other sites.

Dietary antioxidant vitamins intake and mortality: A report from two cohort studies of Chinese adults in Shanghai.

BACKGROUND: Few studies have evaluated dietary antioxidant vitamins intake in relation to risk of mortality in Asia. METHODS: We examined the associations between total carotene, vitamin C, and vitamin E from diet and risk of mortality from all causes, cancer, and cardiovascular disease in 134,358 participants (59,739 men and 74,619 women) from the Shanghai Men's Health Study and Shanghai Women's Health Study, two prospective cohort studies of middle-aged and elderly Chinese adults in urban Shanghai. Participants were followed up for a median period of 8.3 and 14.2 years for men and women, respectively. Hazard ratios (HRs) and 95% confidence interval (CIs) were estimated using Cox proportional hazards regression models. RESULTS: During the 495,332 and 1,029,198 person-years of follow-up for men and women, respectively, there were 10,079 deaths (4170 men and 5909 women). For men, compared with the lowest quintiles, the multivariable-adjusted risk reductions in the highest categories were 17% (HR 0.83; 95% CI, 0.76-0.92) for dietary total carotene and 17% (HR 0.83; 95% CI, 0.75-0.91) for dietary vitamin C. Associations were weaker in women than in men, though they were still statistically significant (highest versus lowest quintiles of dietary total carotene, HR 0.87; 95% CI, 0.80-0.95; dietary vitamin C: HR 0.83; 95% CI, 0.77-0.91). Significant inverse associations were observed between dietary total carotene, vitamin C, and risk of cardiovascular disease mortality but not cancer mortality. CONCLUSION: This study suggests that total carotene and vitamin C intake from diet were inversely associated with deaths from all causes and cardiovascular disease in middle-aged or elderly people in China.

Green tea consumption and cause-specific mortality: Results from two prospective cohort studies in China.

BACKGROUND: Green tea is one of the most widely consumed beverages in Asia. While a possible protective role of green tea against various chronic diseases has been suggested in experimental studies, evidence from human studies remains controversial. METHODS: We conducted this study using data from Shanghai Men's Health Study (SMHS) and Shanghai Women's Health Study (SWHS), two population-based prospective cohorts of middle-aged and elderly Chinese adults in urban Shanghai, China. Hazard ratios (HR) and 95% confidence intervals (CI) for risk of all-cause and cause-specific mortality associated with green tea intake were estimated using Cox proportional hazards regression models. RESULTS: During a median follow-up of 8.3 and 14.2 years for men and women, respectively, 6517 (2741 men and 3776 women) deaths were documented. We found that green tea consumption was inversely associated with risk of all-cause mortality (HR 0.95; 95% CI, 0.90-1.01), particularly among never-smokers (HR 0.89; 95% CI, 0.82-0.96). The inverse association with cardiovascular disease (CVD) mortality (HR 0.86; 95% CI, 0.77-0.97) was slightly stronger than that with all-cause mortality. No significant association was observed between green tea intake and cancer mortality (HR 1.01; 95% CI, 0.93-1.10). CONCLUSIONS: Green tea consumption may be inversely associated with risk of all-cause and CVD mortality in middle-aged and elderly Chinese adults, especially among never smokers.

Dietary selenium intake and mortality in two population-based cohort studies of 133 957 Chinese men and women.

OBJECTIVE: To investigate the potential influence of dietary Se intake on mortality among Chinese populations. DESIGN: We prospectively evaluated all-cause, CVD and cancer mortality risks associated with dietary Se intake in participants of the Shanghai Women's Health Study (SWHS) and the Shanghai Men's Health study (SMHS). Dietary Se intake was assessed by validated FFQ during in-person interviews. Cox proportional hazards models were used to calculate hazard ratios (HR) and 95 % CI. SETTING: Urban city in China. SUBJECTS: Chinese adults (n 133 957). RESULTS: During an average follow-up of 13·90 years in the SWHS and 8·37 years in the SMHS, 5749 women and 4217 men died. The mean estimated dietary Se intake was 45·48 µg/d for women and 51·34 µg/d for men, respectively. Dietary Se intake was inversely associated with all-cause mortality and CVD mortality in both women and men, with respective HR for the highest compared with the lowest quintile being 0·79 (95 % CI 0·71, 0·88; P trend<0·0001) and 0·80 (95 % CI 0·66, 0·98; P trend=0·0268) for women, and 0·79 (95 % CI 0·70, 0·89; P trend=0·0001) and 0·66 (95 % CI 0·54, 0·82; P trend=0·0002) for men. No significant associations were observed for cancer mortality in both women and men. Results were similar in subgroup and sensitivity analyses. CONCLUSIONS: Dietary Se intake was inversely associated with all-cause and cardiovascular mortality in both sexes, but not cancer mortality.

Vitamin E intake and the lung cancer risk among female nonsmokers: a report from the Shanghai Women's Health Study.

Vitamin E includes several tocopherol isoforms, which may reduce lung cancer risk, but past studies evaluating the association between vitamin E intake and lung cancer risk were inconsistent. We prospectively investigated the associations between tocopherol intake from diet and from supplements with lung cancer risk among 72,829 Chinese female nonsmokers aged 40-70 years and participating in the Shanghai Women's Health Study (SWHS). Dietary and supplement tocopherol exposure was assessed by a validated food-frequency questionnaire at baseline and reassessed for change in intake during follow-up. Cox proportional hazards models with time-dependent covariates were used to calculate multivariate-adjusted hazard ratios (HRs) and 95% confidence interval (CIs) for lung cancer. After 12.02 years of follow-up, 481 women were diagnosed with lung cancer. Total dietary tocopherol was inversely associated with lung cancer risk among women meeting dietary guidelines for adequate intake (AI) of tocopherol (14 mg/day or more: HR: 0.78; 95% CI 0.60-0.99; compared with the category less than AI). The protective association between dietary tocopherol intake and lung cancer was restricted to women exposed to side-stream smoke in the home and workplace [HR = 0.53 (0.29-0.97), p-trend = 0.04]. In contrast, vitamin E supplement use was associated with increased lung cancer risk (HR: 1.33; 95% CI: 1.01-1.73), more so for lung adenocarcinoma risk (HR: 1.79; 95% CI: 1.23-2.60). In summary, dietary tocopherol intake may reduce the risk of lung cancer among female nonsmokers; however, supplements may increase lung adenocarcinoma risk and requires further investigation.

Prospective cohort study of tea consumption and risk of digestive system cancers: results from the Shanghai Women's Health Study.

BACKGROUND: Data from in vitro and animal studies support a protective role for tea in the etiology of digestive system cancers; however, results from prospective cohort studies have been inconsistent. In addition, to our knowledge, no study has investigated the association of tea consumption with the incidence of all digestive system cancers in Chinese women. OBJECTIVE: We investigated the association of regular tea intake (≥3 times/wk for >6 mo) with risk of digestive system cancers. DESIGN: We used the Shanghai Women's Health Study, a population-based prospective cohort study of middle-aged and older Chinese women who were recruited in 1996-2000. Adjusted HRs and associated 95% CIs were derived from Cox regression models. RESULTS: After a mean follow-up of 11 y, 1255 digestive system cancers occurred (stomach, esophagus, colorectal, liver, pancreas, and gallbladder/bile duct cancers) in 69,310 nonsmoking and non-alcohol-drinking women. In comparison with women who never drank tea, regular tea intake (mostly green tea) was associated with reduced risk of all digestive system cancers combined (HR: 0.86; 95% CI: 0.74, 0.98), and the reduction in risk increased as the amount and years of tea consumption increased (P-trend = 0.01 and P-trend < 0.01, respectively). For example, women who consumed ≥150 g tea/mo (∼2-3 cups/d) had a 21% reduced risk of digestive system cancers combined (HR: 0.79; 95% CI: 0.63, 0.99). The inverse association was found primarily for colorectal and stomach/esophageal cancers. CONCLUSION: In this large prospective cohort study, tea consumption was associated with reduced risk of colorectal and stomach/esophageal cancers in Chinese women.

Green tea consumption and colorectal cancer risk: a report from the Shanghai Men's Health Study.

Tea and its constituents have demonstrated anticarcinogenic activity in both in vitro and in vivo animal studies. Results from epidemiologic studies, however, have been inconsistent. Some factors that coexist with tea consumption, such as cigarette smoking, may confound or modify the association between tea consumption and cancer risk. The objective of this study was to comprehensively evaluate the association between green tea consumption and colorectal cancer risk in a population-based prospective cohort study, the Shanghai Men's Health Study. The analysis included 60,567 Chinese men aged 40-74 years at baseline. During ∼5 years of follow-up, 243 incident cases of colorectal cancer were identified. Multivariable Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of developing colorectal cancer. Regular green tea consumption (ever drank green tea at least three times per week for more than six consecutive months) was associated with reduced risk of colorectal cancer in non-smokers (multivariable-adjusted HR = 0.54, 95% CI: 0.34-0.86). The risk decreased as the amount of green tea consumption increased (P(trend) = 0.01). Each 2 g increment of intake of dry green tea leaves per day (approximately equivalent to the amount of tea in a tea bag) was associated with a 12% reduction in risk (HR = 0.88, 95% CI: 0.78-0.99). No significant association was found among smokers (HR = 0.94, 95% CI: 0.66-1.34). This study suggests that regular consumption of green tea may reduce colorectal cancer risk among non-smokers.

Fish, shellfish, and long-chain n-3 fatty acid consumption and risk of incident type 2 diabetes in middle-aged Chinese men and women.

BACKGROUND: Long-chain polyunsaturated n-3 (omega-3) fatty acids, found mainly in fish, have been postulated to reduce type 2 diabetes (T2D) risk. However, the role of long-chain n-3 fatty acids and fish intake in the development of T2D remains unresolved. OBJECTIVE: We examined associations between fish, shellfish, and long-chain n-3 fatty acids and the risk of T2D in a middle-aged Chinese population. DESIGN: This was a prospective population-based cohort study in 51,963 men and 64,193 women free of T2D, cardiovascular disease, and cancer at baseline with valid dietary information. Dietary intake, physical activity, and anthropometric measurements were collected. A Cox regression model was used to evaluate the association of fish, shellfish, and long-chain n-3 fatty acid (in g/d) with risk of T2D. RESULTS: Fish, shellfish, and long-chain n-3 fatty acid intakes were inversely associated with T2D in women. The relative risks [RRs (95% CI)] for quintiles of fish intake were 1.00, 0.96 (0.86, 1.06), 0.84 (0.75, 0.94), 0.80 (0.71, 0.90), and 0.89 (0.78, 1.01) (P for trend = 0.003) and for shellfish were 1.00, 0.91 (0.82, 1.01), 0.79 (0.71, 0.89), 0.80 (0.71, 0.91), and 0.86 (0.76, 0.99) (P for trend = 0.006). In men, only the association between shellfish intake and T2D was significant. The RRs (95% CI) for quintiles of fish intake were 1.00, 0.92 (0.75, 1.13), 0.80 (0.65, 1.00), 0.89 (0.72, 1.11), and 0.94 (0.74, 1.17) (P for trend = 0.50) and for shellfish intake were 1.00, 0.93 (0.76, 1.12), 0.70 (0.56, 086), 0.66 (0.53, 0.82), and 0.82 (0.65, 1.02) (P for trend = 0.003). CONCLUSIONS: An inverse association between fish and shellfish intake and T2D in women was found. No evidence of a detrimental effect of fish intake in this population was observed.

Spousal correlations for lifestyle factors and selected diseases in Chinese couples.

PURPOSE: Spouses usually are genetically unrelated and share a common living environment. Thus, concordance of diseases in spouses reflects mainly environmental etiologic contributors. The purpose of this study is to investigate spousal associations for selected lifestyle characteristics and common medical conditions. METHODS: Baseline information from 66,130 married couples participating in the Shanghai Women's Health Study was used in this analysis. Husband-wife associations were evaluated by means of logistic regression, using women's lifestyle and medical conditions as dependent variables. Adjustments were made for women's age, education, occupation, and family income in all models. RESULTS: Women were more than twice as likely to be current or former smokers; be regular consumers of alcohol, tea, and ginseng; and exercise regularly if their husbands had the same habit. A statistically significant husband-wife disease association was found for tuberculosis, chronic bronchitis, asthma, chronic gastritis, chronic hepatitis, ulcerative colitis, cholelithiasis, high blood pressure, coronary heart disease, and stroke. CONCLUSIONS: Spouses share common lifestyle habits and health risks. This study supports the hypothesis that the shared marital environment may contribute to similarities in lifestyle and morbidity in spouses and provides a basis for health promotion and prevention strategies that target the spouses of patients.