British researchers have found that green and black tea inhibit the activity of certain enzymes in the brain, paving the way for improved memory and protecting against the development of Alzheimer's disease.

'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,' said Dr. Edward Okello, lead researcher with the experimental team.

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

The researchers found teas on regular basis inhibited the activity of enzymes in the brain associated with Alzheimer's disease.

The findings, which are published in Phytotherapy Research, were conducted by University of Newcastle researchers through a series of experiments to examine the properties of green tea, black tea and coffee.

They suggest their findings could lead to the development of a new treatment for Alzheimer’s, a form of dementia which affects an estimated 10 million people worldwide. The progression of Alzheimer's can be slowed down with drugs, however, many have unpleasant side effects and tea is being considered as a highly-palatable alternative.

The Trial
The research team from Newcastle University's medicinal plant research centre investigated the properties of coffee and green and black tea in a series of scientific experiments. Traditional English breakfast (black) tea is derived from the same plant as green tea, Camellia sinensis, but has a different taste and appearance because of fermentation.

They found that both green and black tea inhibited the activity of enzymes associated with the development of Alzheimer's Disease, but coffee had no significant effect.

Both teas inhibited the activity of the enzyme acetylcholinesterase (AChE), which breaks down the chemical messenger or neurotransmitter, acetylcholine. Alzheimer's is characterized by a drop in acetylcholine, report the scientists.

Although green tea and black tea both inhibited the activity of enzymes associated with the development of Alzheimer's Disease, green tea went one step further and also obstructed the activity of beta-secretase, which is linked to the production of protein deposits in the brain associated with Alzheimer's disease. Scientists also found that it continued to have its inhibitive effect for a week, whereas black tea's enzyme-inhibiting properties lasted for just one day.

Further Research
The researchers are now seeking funding to continue further testing on green tea, which they hope will include clinical trials. They hope to develop a medicinal tea specifically aimed at Alzheimer's patients.

Finding the components of green tea that inhibits the activity of the enzymes AChE, BuChE and beta-secretase is the next step, according to the researchers.

'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,' Okello said.