|October 26, 2004
Tea contains compounds that may help to keep the brain healthy, say British researchers. Sipping the popular beverage won't guarantee you won't get Alzheimer's or slow its progression, the researchers say. But in test tube studies at least, compounds in both green and black tea mimicked some of the beneficial effects of prescription Alzheimer's drugs.
"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," study leader Ed Okello said. These conclusions are based on early, preliminary findings.
The researchers, from the University of Newcastle's Medicinal Plant Research Centre, found that both green and black tea inhibited the activity of various enzymes associated with the onset of Alzheimer's disease. Both types of tea, for example, inhibited the activity of a brain enzyme called acetylcholinesterase. The popular Alzheimer's drugs Reminyl, Exelon, and Aricept have a similar effect in the brain. Green tea had the added benefit of suppressing activity of beta-secretase, another enzyme that researchers believe plays a role in Alzheimer's development. Coffee, on the other hand, had little effect.
Both green and black teas are made from the same herb, Camellia sinensis, but green tea is not fermented and may be more potent. In the current study, the effects of green tea lasted for up to a week, versus just a day for black tea.
It is unclear, however, whether tea has actual benefits in real life. Rates of Alzheimer's are not known to be lower in countries where tea is especially popular, such as Britain, China, and Japan. The researchers said the next step is to find out exactly which components of tea inhibit the activity of brain enzymes and to conduct further tests in animals to see if such components, once purified, retain their enzyme-inhibiting effects or can be made more potent.
In the meantime, taking a tea break usually won't hurt and may help. Tea is rich in antioxidants and other substances that are thought to benefit blood vessel health. It may also help protect against heart disease and certain forms of cancer. And at the least, a cup of tea can provide a pleasant stress-reducing break during the day.
By www.ALZinfo.org, The Alzheimer's Information Site. Reviewed by , Ph.D., Fisher Center for Alzheimer's Research Foundation at The Rockefeller University.
Edward J. Okello, Sergey U. Savelev, Elaine K. Perry: "In vitro anti-Beta-secretase and dual anti-cholinesterase activities of Camellia sinensis L. (tea) relevant to treatment of dementia." Phytotherapy Research, Volume 18, Issue 8, pages 624-627, October 8, 2004.