1.
Tea consumption and lung cancer risk: a meta-analysis of case-control and cohort studies.
Wang, L, Zhang, X, Liu, J, Shen, L, Li, Z
Nutrition (Burbank, Los Angeles County, Calif.). 2014;(10):1122-7
Abstract
OBJECTIVE Recent epidemiologic studies, especially cohort and case-control studies, have yielded inconsistent findings regarding the association between tea consumption and risk for lung cancer. The aim of this study was to assess a potential relationship between tea consumption and the incidence of lung cancer worldwide. METHODS A systematic literature search of PubMed, Web of Science, the Cochrane Library, Google Scholar, the Chinese Biomedical Database, and Wanfang Database was conducted from 1966 to January 2014 by two investigators. All cohort studies and case-control studies that evaluated the association of tea and lung cancer were included. Summary relative risks (RR) and the corresponding 95% confidence intervals (CIs) were calculated using a random-effects model. Quality assessments were performed using the Newcastle-Ottawa Scale. Heterogeneity was assessed using the Q and I(2) tests, and the source of heterogeneity was detected by meta-regression analysis. Publication bias was evaluated with Egger's regression symmetry test. Subgroup analyses and sensitivity analysis were performed. RESULTS Thirty-eight lung cancer studies (26 case-control studies and 12 cohort studies) with 59,041 cases and 396,664 controls were included. Overall tea consumption was significantly associated with decreased risk for lung cancer (RR, 0.78; 95% CI, 0.70-0.87). Subgroup analyses showed that tea consumption was associated with reduced risk for lung cancer in women (RR, 0.76; 95% CI, 0.62-0.93), case-control studies (RR 0.72; 95% CI 0.63-0.83), Western studies (RR, 0.85; 95% CI, 0.75-0.97), and studies in China and Japan (RR, 0.74; 95% CI, 0.62-0.88). Both green tea (RR, 0.75; 95% CI, 0.62-0.91) and black tea (RR, 0.82; 95% CI, 0.71-0.94) were significantly associated with reduced lung cancer risk. No significant association was found in men or in cohort studies. CONCLUSION Tea consumption may offer some protection against lung cancer.
2.
Strawberry consumption is associated with increased antioxidant capacity in serum.
Henning, SM, Seeram, NP, Zhang, Y, Li, L, Gao, K, Lee, RP, Wang, DC, Zerlin, A, Karp, H, Thames, G, et al
Journal of medicinal food. 2010;(1):116-22
Abstract
Strawberries are known to contain antioxidants, but the significance of ingesting antioxidant-rich fruits remains to be established. In order to determine whether the consumption of strawberries impacted measures of in vivo antioxidant capacity, frozen strawberries (250 g) were administered daily for 3 weeks to 21 healthy female volunteers. Compliance was confirmed by quantitating pelargonidin-glucuronide, urolithin A-glucuronide, and 2,5-dimethyl-4-hydroxy-3-[(2)H]furanone-glucuronide in plasma and urine by liquid chromatography-mass spectrometry and antioxidant capacity in serum measured by the increase in lag phase of low-density lipoprotein after copper sulfate exposure, DNA strand breaks in lymphocytes, and activity of phase II enzymes. Among these measures lipid peroxidation lag time increased by 20% (P < .01), whereas other measures did not change significantly. The potent antioxidant defenses in humans make determination of changes due to dietary ingestion in healthy individuals difficult. In summary, daily consumption of strawberries resulted in a modest but significant increase in antioxidant capacity in a healthy population.