A flurry of new studies is raising hope green tea may someday be a potent weapon in the fight against Alzheimer’s disease and other forms of dementia. Although the studies differ widely in technique, all focus on ways polyphenol compounds in green tea affect important areas of the brain.
The studies used extracts of green tea---notably a polyphenol compound called EGCG (epigallocatechin-3-gallate), but experts say similar benefits could be gained simply by sipping tea (1).
“As some research has revealed the potential benefit of selected vitamins and fatty acids in promoting cognitive function, recent studies on flavonoids, which are phytochemicals especially rich in plant foods like berries and tea, show they too may act to promote brain performance and/or reduce the risk for neurodegenerative conditions,” says Jeffery Blumberg, PhD, director of Tufts’ HNRCA Antioxidants Research Laboratory (1).
Very Exciting Findings from Several Rearch Studies:
1. Research on green tea, specifically EGCG, found green tea extract was associated with increased activity in the dorsolateral prefrontal cortex of the brain. That’s a key area for working-memory processing (2).
2. Two other new studies tested whether green tea extracts could block the formation of the amyloid plaques associated with Alzheimer’s disease. They found the green tea compound prevented the formation of the potentially dangerous amyloid aggregates. The EGCG extract also actually broke down existing aggregates in proteins that contained metals—copper, iron and zinc—associated with Alzheimer’s disease (3, 4).
If you’re looking to sip some EGCG, white and green tea have the highest concentration of EGCG, oolong tea the ‘middle’ amount, and black tea the least. It appears, however, gut bacteria can metabolize compounds in black and oolong tea into EGCG. In other words, your intestinal bacteria can partially turn black tea into green tea (1).
Also consider taking a green tea extract supplement.
Much more research needs to be done, but this is an excellent and promising start! Finding a preventative to such an awful, debilitating disease like Alzheimer’s would be amazing!
In Health and Happiness,
Kelly Harrington, MS, RDN
Registered Dietitian Nutritionist for Healthy Goods
1. Rosenberg, Irwin H., MD. "Green Tea Protects Brain Cells." Tufts University Health & Nutrition Letter 31, No.4 (June 2013): 7. Print.
2. S Borgwardt, F Hammann, K Scheffler, M Kreuter, J Drewe and C Beglinger. Neural effects of green tea extract on dorsolateral prefrontal cortex. European Journal of Clinical Nutrition 66, 1187-1192 (November 2012)
3. Hyunge, Suk-Joon, DeToma, Alaina S., Brender, Jeffrey R., et al. Insights into antiamyloidogenic properties of the green tea extract (−)-epigallocatechin-3-gallate toward metal-associated amyloid-β species. PNAS 2013 110 (10) 3743-3748
4. Rushworth, Jo V., Griffiths, Heledd H., Watt, Nicole T., and Hooper, Nigel M. Prion Protein-mediated Toxicity of Amyloid-β Oligomers Requires Lipid Rafts and the Transmembrane LRP1 J. Biol. Chem. 2013 288: 8935-8951.