Digested green tea prevents dementia like Alzheimer's
Drinking green tea regularly may help protect against developing dementia such as Alzheimer's disease, according to a study led by Newcastle University researchers.
The study in the journal Phytomedicine also suggests green tea, commonly consumed in China, Japan and other Asian countries may play an important role in preventing carcinogenesis or cancer development.
The study led by Ed Okello was meant to see if digestion in the gut could affect the protective effect of green tea, which is known to be active when freshly brewed.
What the researchers found is that digestion by enzymes in the gut results in compounds that are more effective than the undigested compounds against factors that are known to cause Alzheimer's disease.
These were found to protect the brain by interacting with hydrogen peroxide and beta-amyloid which would otherwise increase risk of Alzheimer's.
Previous studies, such as Skrzypczak-Jankun E and Jankun J as reported in the July 2010 issue of International Journal of Molecular Medicine, found that theaflavin digallate in green tea as well as black tea and their derivatives can inhibit PAI-I and alleviate the symptoms of Alzheimer's disease.
The researchers found EGCG did not inactivate PAI-I as efficiently as theaflavin digallate.
Additionally, digested green tea contains many anticancer compounds, which slow down the growth of tumor cells as tested in the researchers' laboratory. Green tea has been associated with low incidence of some cancers including stomach cancer.
Kang H and colleagues from Yonsei University in Seoul Korea reported in the April 2010 issue of Epidemiology and Health that those who drank five or more cups of green tea a day were 32 percent less likely to acquire stomach cancer, compared with those who drank little green tea.
Rutgers University scientists like C.S. Yang have demonstrated early that undigested green tea compounds like Epigallocatechin gallate or EGCG promotes apoptosis (programmed cell deaths) which are not found as much in the cancer cells as in the healthy cells. That is why drinking green tea help reduce cancer risk.
The U.S. Food and Drug Administration has not agreed that drinking green tea can prevent Alzheimer's disease and cancer.
David Liu and editing by Denise Reynolds
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