Animal and in vitro studies have shown that various molecular mechanisms, including antioxidant effects, acetylcholinesterase (AChE) inhibition, reduction of amyloid-β accumulation and tau aggregation, and reduction of cerebrovascular disease risk by suppressing atherosclerosis, may contribute to the preventive effects of tea and bioactive compounds in tea on dementia [[16], [17], [18], [19], [20]]. The gene discussed is MAPT; the disease is dementia.