Tea polyphenols, particularly epigallocatechin gallate (EGCG) found in green tea, have been studied for their neuroprotective properties and potential benefits in Alzheimer's Disease (AD). Laboratory and animal studies indicate that tea polyphenols may inhibit the aggregation of amyloid-beta peptides—a hallmark of AD pathology—reduce oxidative stress, and mitigate neuroinflammation. These mechanisms suggest a plausible biological rationale for investigating tea polyphenols as supportive agents in AD.

However, the current evidence from human clinical trials is limited and largely inconclusive. While several small-scale, short-term studies (mostly observational or pilot intervention trials) have reported associations between higher tea consumption and reduced cognitive decline, robust randomized controlled trials specifically evaluating tea polyphenols for AD prevention or treatment are lacking. Systematic reviews of the literature highlight the need for more rigorous human studies to confirm efficacy, establish optimal dosages, and evaluate long-term safety.

In summary, the use of tea polyphenols for Alzheimer's Disease is supported by promising preclinical evidence and some preliminary human data, but clinical validation remains insufficient. The evidence strength is therefore rated as 2 out of 5, indicating early scientific interest with limited clinical confirmation.