Epigallocatechin gallate (EGCG) is a major catechin found in green tea and is widely studied for its antioxidant properties. Scientific evidence supports EGCG’s role in combating free radical damage, primarily due to its ability to scavenge reactive oxygen species (ROS) and enhance endogenous antioxidant defense systems. Numerous in vitro and in vivo studies have demonstrated that EGCG can neutralize free radicals, thereby potentially reducing oxidative stress and cellular damage. For example, reviews such as those published in the Journal of Nutritional Biochemistry (2011) and Food & Function (2014) summarize how EGCG inhibits lipid peroxidation, DNA damage, and protein oxidation in various biological models.

Animal studies have shown that EGCG supplementation increases levels of endogenous antioxidants like superoxide dismutase (SOD) and glutathione peroxidase (GPx), further supporting its role in protecting cells from oxidative stress. However, clinical evidence in humans is less extensive and more variable. Some clinical trials report improvements in biomarkers of oxidative stress following green tea or EGCG supplementation, while others show minimal effects, possibly due to differences in study design, dose, or duration.

In summary, there is significant preclinical evidence and some clinical support for the use of EGCG in protecting against free radical damage, justifying its inclusion as an antioxidant ingredient. However, further high-quality human trials are needed to confirm its efficacy and establish optimal dosing regimens.