Green tea consumption has been associated with delayed onset or progression of cardiovascular disorders, metabolic diseases, and hypertension, but its effect on blood lipids remains less clear. Researchers performed a literature review and meta-analysis to ascertain what effects green tea has on blood lipids and observed a benefit for low-density lipoprotein (LDL) cholesterol and total cholesterol.
PubMed, Embase, and the Cochrane Library were queried for relevant studies published from inception through September 2019. Blood lipid changes were compared between green tea supplementation versus control groups by determining the weighted mean differences (WMDs).
Final meta-analysis included 31 trials encompassing 3,321 total patients. Overall, a significant association was observed between green tea intake and lower total cholesterol (WMD, –4.66 mg/dL; 95% confidence interval [CI], –6.36 to –2.96 mg/dL; P<0.0001), as well as LDL cholesterol (WMD, –4.55 mg/dL; 95% CI, –6.31 to 2.80 mg/dL; P<0.0001), levels, when comparing patients drinking green tea versus control patients. There was no association between green tea consumption and high-density lipoprotein cholesterol, but a correlation was observed between green tea consumption and reduced triglycerides versus the control group (WMD, –4.55 mg/dL; 95% CI, –6.31 to –2.80 mg/dL; P<0.0001). Funnel plots and Egger’s tests did not yield significant publication bias.
The study authors concluded, “Additional large prospective cohort studies are needed to provide a more definitive conclusion on the association between routine consumption of green tea and lipid metabolism.”