Regularly drinking green tea could protect the brain against developing Alzheimer’s and other forms of dementia, according to the latest research by scientists at Newcastle University, UK. The study, published in the academic journal Phytomedicine, also suggests this ancient Chinese remedy could play a vital role in protecting the body against cancer.
Led by Dr. Ed Okello, the Newcastle team wanted to know if the protective properties of green tea—which have previously been shown to be present in the undigested, freshly brewed form of the drink—were still active once the tea had been digested.
As part of the research, the Newcastle team worked in collaboration with Dr. Gordon McDougall of the Plant Products and Food Quality Group at the Scottish Crop Research Institute in Dundee, who developed technology that simulates the human digestive system. The team analyzed that two compounds are known to play a significant role in the development of Alzheimer’s disease—hydrogen peroxide and a protein known as beta-amyloid.
Previous studies have shown that compounds known as polyphenols, present in black and green tea, possess neuroprotective properties, binding with the toxic compounds and protecting the brain cells. When ingested, the polyphenols are broken down to produce a mix of compounds and it was these the Newcastle team tested in their latest research.
“There are certain chemicals we know to be beneficial and we can identify foods which are rich in them, but what happens during the digestion process is crucial to whether these foods are actually doing us any good,” explained Okello.
Carrying out the experiments in the lab using a tumor cell model, they exposed the cells to varying concentrations of the different toxins and the digested green tea compounds.
Okello said, “The digested chemicals protected the cells, preventing the toxins from destroying the cells. We also saw them affecting the cancer cells, significantly slowing down their growth.”
The next step is to discover whether the beneficial compounds are produced during digestion after healthy human volunteers consume tea polyphenols. The team has already received funding from the Biotechnology and Biological Sciences Research Council (BBSRC) to take this forward.