Effect of green tea consumption on blood lipids: a systematic review and meta-analysis of randomized controlled trials

Xu R, Yang K, Li S, Dai M, Chen G · Nutrition Journal · 2020 September 16

Objective

The study aimed to conduct a literature review and meta-analysis to assess the effect of green tea on blood lipids, particularly total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides.

Conclusions

The meta-analysis, incorporating 31 trials with 3321 subjects, revealed that green tea intake significantly lowered both total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol levels compared to the control. However, it did not significantly affect high-density lipoprotein (HDL) cholesterol, and while there was a reduction, it was not statistically significant for triglycerides. The study suggests that green tea consumption has a positive impact on LDL cholesterol and TC levels, but additional well-designed studies with diverse populations and longer durations are needed for further confirmation.

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Insights

The consumption of green tea significantly lowers low-density lipoprotein cholesterol and total cholesterol, but it does not affect high-density lipoprotein cholesterol or triglycerides.

To gather data for this study, a comprehensive literature review and meta-analysis were conducted using PubMed, Embase, and the Cochrane Library. The databases were searched from their inception to September 2019 for all studies related to the effect of green tea on blood lipids. Information from these studies, which included randomized and controlled trials, was used to estimate blood lipid changes resulting from green tea supplementation. The collected information underwent rigorous assessment for any potential bias. The analysis of data derived from 31 different trials involving a total of 3321 subjects showed that green tea intake has a significant effect in lowering low-density lipoprotein cholesterol and total cholesterol levels. However, consumption of green tea did not yield significant changes in the levels of high-density lipoprotein cholesterol or triglycerides. The results remained consistent across both normal-weight and overweight-obese subjects. No significant publication bias was detected from the collected studies, fortifying the reliability of the results.