Increased tea consumption is correlated with reduced incidence of dementia, Alzheimer’s and Parkinson’s disease (Mandel 2008). Green tea contains antioxidant polyphenols known to be protective against a host of chronic age related conditions. There is tremendous scientific interest in green tea and its active compound Epigallocatechin gallate (EGCG) as a neuroprotectant in Parkinson’s disease; especially since when compared to many drugs, EGCG is extremely effective at penetrating brain tissue (Levites 2001; Pan 2003).
Israeli researchers showed that they could prevent the cellular changes associated with Parkinson’s by pre-treating mice with either green tea extracts or EGCG ahead of inducing the disease by chemical injection (Levites 2001; Levites 2002). This research has subsequently been repeated and extended in laboratories around the world (Choi 2002; Nie 2002; Mandel 2004; Guo 2005; Guo 2007). Utilizing the brain cell cultures pretreated to develop Parkinson’s-like changes, the Israeli group also showed that green tea extracts prevented activation of the inflammation producing NF-kappaB system (Levites 2002). EGCG’s specific anti-inflammatory properties have been demonstrated to protect cultured brain tissue from the loss of dopaminergic cells as well (Li 2004). L-theanine, a component of green and black tea, was shown by Korean scientists to prevent dopaminergic cell death such as that seen in Parkinson’s disease (Cho 2008).
Another potential benefit of green tea extract is its ability to inhibit the dopamine degrading enzyme COMT (Chen 2005). This may help to sustain dopamine levels in ailing brain tissue thereby reducing the severity of symptoms.
Just as we use multiple combinations of prescription drugs to capitalize on their synergistic effects, we can capitalize on green tea’s neuroprotective effects in Parkinson’s and other neurodegenerative diseases (Mandel 2008). While more human studies are yet to be completed, green tea polyphenols have proven to exert powerful protection for dopaminergic neurons making them a key component in the prevention and treatment of Parkinson’s disease (Guo 2007; Li 2006; Ramassamy 2006; Avramovich-Tirosh 2007; Zhao 2009).