Green tea may be effective against Alzheimer′s disease, UK study says | Science| In-depth reporting on science and technology | DW | 06.01.2011
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Green tea may be effective against Alzheimer's disease, UK study says

Newcastle scientists show that green tea, when digested, cause anti-Alzheimer's compounds to form. Longer-term, multi-year human trials are now around the corner.

A green tea plant with flower

Regular intake of green tea may fight Alzheimer's

That there is more to green tea than refreshment is no secret.

Over the past decade or so, the bitter beverage has repeatedly cropped up in scientific literature as a possible plant-based remedy for diseases such as Alzheimer's.

In order to assess the accuracy of such big claims, scientists from Newcastle University's Medicinal Plant Research Group have spent the last four years monitoring the effects of this ancient herbal brew.

In a new paper published today in the journal Phytomedicine, the team's trials showed that the tea's properties during digestion cause the stomach's enzymes to create chemicals which work against the key triggers of Alzheimer's – hydrogen peroxide and the protein, beta-amyloid.

Fighting the root cause

Using technology which simulates the human digestive system, the research group led by Edward Okello, was able to compare the medicinal value of the tea both before and after consumption.

"Past work has been on purified compounds from green tea, or extracts of green tea which have not gone through the digestion process," Okello told Deutsche Welle.

"But we have seen that after digestion the compounds available for consumption still have their properties."

A scan picture of Alzheimer cells

Alzheimer's is a debilitating and devastating disease for patient and family

While the findings , are all lab-based, the Newcastle University team has received funding to start human trials, which will run for between four and five years and will aim to isolate the health benefits of a range of green and black teas.

"Our theory is that if you can prevent the initial triggers, you can potentially prevent the onset of dementia," he said. "Or with greater consumption, you could slow down progression."

Okello says they will begin with healthy volunteers and those with early onset dementia, and possible some cancer patients.

Tackling cancer with tea

Besides revealing green tea as a source of much needed protection against Alzheimer's disease and other forms of dementia, the scientists also established its anti-cancer benefits. They cultivated fast-growing tumor cells and monitored their reaction to digested green tea.

A cup of green tea

The research team hopes to extend its green tea experiment to human subjects in the coming years

"Higher concentrations of tea started to kill the tumor cells in our study," Okello said. "So it has a dual benefit in terms of protecting against toxicity and being able to reduce the proliferation of tumor cells."

He said he was particularly interested to establish any positive effects of green tea on those suffering from cancer of the mouth.

"We know that the enzymes break down tea quickly in the mouth and the cavity in the mouth is the first to absorb the tea compounds, so does that mean it protects cells from damage?"

Back to the future

Okello freely admits that he was as surprised as he was excited by the findings of his research, but says he believes studies such as his will eventually lead modern medicine "back to the future, to plants."

Christian Kuhlman, head of the Traditional Chinese Medicine Centre at the Johanniter Hospital in the German town of Radevormwald is not surprised by the findings.

He told Deutsche Welle that there is enough ill feeling about modern medicine to ultimately push alternatives to the fore.

"Patients don't always want to take pills or antibiotics," he said, adding that medicine would have progressed further if the same money which has been invested in chemical pharmaceuticals over the years had been ploughed into phytopharmaceutics.

"There is no need to reinvent the wheel," he said. "There are a lot of very useful substances in the natural world, be they in Europe or China."

And if Okello is right, they are going to be appearing on the lists of ingredients for more and more drugs in the future.

Author: Tamsin Walker
Editor: Cyrus Farivar

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