A NICE cup of tea looks like being just what the doctor ordered all along, a new North East study suggests.
According to research by experts at Newcastle University, regularly drinking green tea could protect the brain against developing Alzheimer’s disease and other forms of dementia.
The study, published today, also suggests that green tea – part of Far Eastern medicinal use for centuries – could play a key role in protecting the body against cancer.
Although the study concentrated on green tea, Dr Ed Okello, who led the Newcastle team, said yesterday that black tea – the most commonly drunk in the UK – was also known to have benefits for the heart and in reducing cholesterol levels, as well as anti-cancer properties.
In the new study, the Newcastle scientists wanted to see 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.
Dr Okello said that because food is generally accepted to contain health-boosting properties, it can’t be assumed these compounds will be absorbed by the body.
“What was really exciting about this study was that we found when green tea is digested by enzymes in the gut, the resulting chemicals are actually more effective against key triggers of Alzheimer’s development than the undigested form of the tea,” said Dr Okello, based in the School of Agriculture, Food and Rural Development at Newcastle University.
“We also found the digested compounds had anti-cancer properties, significantly slowing down the growth of the tumour cells which we were using in our experiments. It was amazing.”
The Newcastle team worked with Dr Gordon McDougall at the Scottish Crop Research Institute in Dundee, who has developed technology which simulates the human digestive system.
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.
Carrying out the experiments in the lab using a tumour cell model, they exposed the cells to varying concentrations of the different toxins and the digested green tea compounds.
Dr 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.
“Green tea has been used in traditional Chinese and Japanese medicine for centuries and what we have here provides the scientific evidence why it may be effective against some of the key diseases we face today.
“There are obviously many factors which together have an influence on diseases such as cancer and dementia – a good diet, plenty of exercise and a healthy lifestyle are all important.
“But I think it’s fair to say that at least one cup of green tea every day may be good for you. I drink it and I would certainly recommend it.”
