AUTHOR=Guan Xifei , Liu Nawen , Zhu Zhixin , Xu Yanxue , Xiong Dehai , Li Xiuyang 

TITLE=Association of tea and its extracts with colorectal adenomas: meta-analysis and systematic review

JOURNAL=Frontiers in Nutrition

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2023.1241848

DOI=10.3389/fnut.2023.1241848

ISSN=2296-861X

ABSTRACT=<sec id="sec1"><title>Background</title><p>There are many studies on the association of tea and its extracts with colorectal adenomas, but the results have varied. The study aims to investigate the effect of tea and its extracts on colorectal adenomas using meta analysis and systematic review.</p></sec><sec id="sec2"><title>Methods</title><p>Literature was obtained through PubMed, Cochrane Library, Embase and Chinese BioMedical Literature Service System since the establishment of the database until April 31, 2023. Search terms include adenomas, polyps, colorectal, rectal, rectum, tea, epigallocatechin, drinking and beverages. Meta-regression analysis was used to infer the source of heterogeneity. Heterogeneity was assessed using <italic>I<sup>2</sup></italic> statistics and <italic>Q</italic> test. The effect measures were odds ratio (OR) and 95% confidence interval (95% CI). Stata17.0 software was used for data processing.</p></sec><sec id="sec3"><title>Results</title><p>The findings indicated that study design (<italic>t</italic> = 0.78, <italic>P</italic> = 0.454), types of tea intake (<italic>t</italic> = 1.35, <italic>P</italic> = 0.205), occurrences (<italic>t</italic> = -0.19, <italic>P</italic> = 0.852), regions (<italic>t</italic> = 1.13, <italic>P</italic> = 0.281) and grades of adenomas (<italic>t</italic> = 0.06, <italic>P</italic> = 0.952) were statistical homogeneity. Tea and its extracts were negatively correlated with the risk of colorectal adenomas (OR = 0.81, 95% CI: 0.66–0.98). No publication bias was found in this study (<italic>t</italic> = -0.22, <italic>P</italic> = 0.828) and the results are robust.</p></sec><sec id="sec4"><title>Conclusion</title><p>This study suggests that tea and its extracts have a certain protective effect on colorectal adenomas, which provides scientific evidence for preventive strategies for colorectal adenomas. As for the causal relationship between tea and its extracts on colorectal adenomas, further prospective studies are needed.</p></sec>