There might be much more to your daily cuppa than an opportunity to take a break. Intensive research into the chemical constituents of tea suggest that it could prove useful in reducing the risk of heart attacks, cancer and Alzheimer's Disease.
Prof Michael Hynes, associate professor of chemistry at NUI Galway, is engaged in a £43,000, three-year Enterprise Ireland-funded research project to study how chemicals in tea, known as polyphenols or flavonoids, might aid disease prevention.
Polyphenols are plant compounds which produce pigmentation in flowers and leaves. They are also known to be powerful antioxidants, substances which latch on to and neutralise free oxygen in the body which might otherwise cause damage. If unchecked these oxygen radicals can bind to genetic material which increases the risk of mutations, which can lead to cancers. There is much research which suggests that antioxidants help by reducing cell damage.
Prof Hynes is studying green tea, the most popular brew in China and Japan. We and other Western countries tend to prefer black tea. Although both varieties contain polyphenols, green tea contains up to five times as much of a particular hydroxyl-rich polyphenol which is very good at binding oxygen radicals.
These polyphenols do more than react with oxygen radicals, however. Prof Hynes's research focuses on the way polyphenols interact with metals, in particular iron and aluminium. Our red blood cells need iron to do their job properly and excess aluminium has been noted in Alzheimer's patients, so his work may become very important in understanding diseases associated with the way we process these metals.
"In order to study these effects we are currently carrying out research into the kinetics and mechanisms of the reactions of iron and aluminium with polyphenols found in green tea," explained Mr Mairtin O Coinceanainn, who is working with Prof Hynes on the project.
The polyphenol's hydroxyl groups which bind oxygen so well also react with these metals. There was an upside and a downside to this, however, said Prof Hynes. While they might make iron compounds in our food more "bioavailable" and easier to absorb, they might also make aluminium more mobile in the body, which could have implications in Alzheimer's Disease.
These reactions are now under scrutiny at NUI Galway. The researchers want to know the initial polyphenol-metal reaction and then subsequent intermediate reactions as the body's systems break them down. While there has been much work on the antioxidant properties of polyphenols there had been no previous detailed studies of this kind on the metal reactions, said Prof Hynes.It was a "first of its kind" for Ireland and Britain.
Initially, the researchers are using off-the-shelf polyphenols: synthesised, refined compounds. The next research phase, however, would call for "genuine" polyphenols derived directly from tea. These represent a complex mix of polyphenol types which may respond differently to the metals of interest to Prof Hynes.
So will drinking gallons of green tea keep you healthy? Some of the studies were contradictory, said Prof Hynes. A study in the Netherlands found that tea flavonoid consumption was matched by a reduced incidence of heart attack and stroke in men. A similar study in Wales, however, failed to establish this relationship. This study did suggest, however, that adding milk to tea, as is commonly done in Wales and Ireland, might destroy or reduce the tea's antioxidant potential.
The Lyons tea company was quick to promote new research published in the American Journal of Epidemiology entitled "Coffee and Tea Intake and the Risk of Myocardial Infarction" (heart attack to you and me). This work found that drinking one or more cups of black tea per day was associated with a 44 per cent reduction in the risk of heart attack.