Country  United Kingdom

     Date  26 October 2004

     A team from Newcastle University found green and black tea inhibited
the activity of key enzymes in the brain associated with memory.

     The researchers hope their findings, published in Phytotherapy
Research, may lead to the development of a new treatment for Alzheimer's
Disease.

     They say tea appears to have the same effect as drugs specifically
designed to combat the condition.

     Alzheimer's disease is associated with a reduced level of a chemical
called acetylcholine in the brain.

     In lab tests, the Newcastle team found that both green and black tea
inhibited the activity of the enzyme acetylcholinesterase (AChE), which
breaks down this key chemical.

     They also found both teas inhibited the activity of a second enzyme
butyrylcholinesterase (BuChE), which has been discovered in protein deposits
found in the brain of patients with Alzheimer's.

     Green tea went one step further in that it obstructed the activity of
beta-secretase, which plays a role in the production of protein deposits in
the brain which are associated with Alzheimer's disease.

     The scientists also found that it continued to have its inhibitive
effect for a week, whereas black tea's enzyme-inhibiting properties lasted
for only one day.

     There is no cure for Alzheimer's but it is possible to slow the
development of the disease.

     Drugs currently on the market hinder the activity of AChE, and others
are being developed which scientists hope will inhibit the activity of BuChE
and beta-secretase.

     However, many of the drugs currently available, such as donepezil,
have unpleasant side effects and the medical profession is keen to find
alternatives.

     The Newcastle University researchers are now seeking funding to carry
out further tests on green tea, which they hope will include clinical
trials.

     Their aim is to work towards the development of a medicinal tea which
is specifically aimed at Alzheimer's sufferers.

     The next step is to find out exactly which components of green tea
inhibit the activity of the enzymes AChE, BuChE and beta-secretase.

     Lead researcher Dr Ed Okello said: "Although there is no cure for
Alzheimer's, tea could potentially be another weapon in the armoury which is
used to treat this disease and slow down its development.

     "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."

     Professor Clive Ballard, director of research, Alzheimer's Society,
said: "This interesting research builds on previous evidence that suggests
that green tea may be beneficial due to anti-oxidant properties.

     "Certainly the effect on the cholinesterase enzyme (the target of
current anti-dementia drugs such as Aricept) and beta-secretase (an enzyme
which is important in the build up of plaques) is very exciting and requires
further investigation."

     Black tea - traditional English breakfast tea - is derived from the
same plant as green tea, Camellia sinensis, but has a different taste and
appearance because it is fermented.

      Source: BBC News Online, 25/10/2004