Drinking two cups of green tea a day could, over time, halve a person’s risk of having the most common form of stroke, Australian researchers say.

Researcher Professor Colin Binns, of the School of Public Health at Curtin University in Western Australia, says their research shows people who drink at least one cup of green tea a day reduce their risk of ischemic stroke.

For those who drink more than two cups daily the risk is cut by as much as 60%.

“We can say if you are going to drink a beverage, then tea is the healthier option,” says Binns.

If green tea does not take your fancy, black teas also reduce risk, albeit not as much.

“We believe other kinds of tea are half as effective as green tea in reducing risk,” says Binns.

The findings, published this week in the journal Stroke, follow on from earlier research by the same group that found green tea also cuts ovarian and prostate cancer risk.

Binns says the results could help reduce the incidence of strokes, which account for more than five million deaths worldwide each year.

China study
The study tracked green tea consumption among ischemic stroke patients in the southern Chinese province of Guangdong.

Ischemic strokes, which are those caused by a clot that cuts off blood to the brain, account for about 70% of all strokes that occur.

The research, which included academics from the Curtin Health Innovation Research Institute and three Chinese hospitals, was conducted between 2007 and 2008.

The study interviewed 400 patients diagnosed as having had a stroke and 400 healthy people.

Binns says the choice of basing the research in southern China was important because the diet in that area has been relatively unchanged for the past 10-20 years, the population is homogenous and tea drinking is a traditional practice.

He says because people’s tastes in Australia are constantly changing, it would be hard to replicate the study here.

However, the researchers believe green tea would have the same benefits within a western diet.

A steaming cup of tea could help ward off the effects of Alzheimer’s disease, say U.K. scientists.

Laboratory tests found that regular cups of green and black tea inhibit the activity of certain brain enzymes that bring on Alzheimer’s, a form of generative dementia that affects an estimated 10 million people worldwide.

But the researchers are not sure if tea’s active ingredients would work in the body, particularly if they would reach the brain.

The research by the medicinal plant research centre at University of Newcastle upon Tyne, northeast England, is published in the journal Phytotherapy Research.

Scientists tested coffee as well as green and black tea. Coffee had no significant effect on the activity of enzymes associated with developing Alzheimer’s. But both green and black tea inhibited the enzymes.

According to the journal, tea inhibited the activity of the enzyme acetylcholinesterase, which breaks down the chemical messenger, or neurotransmitter acetylcholine.

Alzheimer’s is characterised by a drop in acetylcholine.

Green tea and black tea also hindered the activity of the enzyme butyrylcholinesterase, seen in protein deposits found on the brains of patients with Alzheimer’s.

But green tea alone had a further effect, obstructing the activity of beta-secretase, which has a role in the production of protein deposits in the brain associated with Alzheimer’s.

The effects of green tea also last a week, scientists found, as against only a day for black tea.

“Although there is no cure for Alzheimer’s, tea could potentially be another weapon in the armory which is used to treat this disease and slow down its development,” said head researcher Dr Ed Okello.

“It would be wonderful if our work could help improve the quality of life for millions of sufferers and their carers.

“Our findings are particularly exciting as tea is already a very popular drink, it is inexpensive, and there do not seem to be any adverse side effects when it is consumed.

“Still, we expect it will be several years until we are able to produce anything marketable.”