Green Tea Against Viruses
Bacteria are not the only microscopic troublemakers. Viruses, tiny microorganisms that "hijack" their host's cells, are the source of some of the most dangerous and communicable diseases in the world, including AIDS. And viruses can attack plants as well as humans and animals. Taking their cue from Japanese tobacco growers who used an extract of green tea to stop the growth of the "tobacco mosaic virus," scientists tested EGCg and ECg against a cell culture that was given a dose of a rotavirus. Both of these catechins inhibited the viral infection of the cells. Since that time, tea leaves have been found to have antiviral activity against the influenza (flu) virus, herpes simplex virus, vaccinia virus, Coxsackie virus B6, and polio virus 1, all of which cause serious diseases in humans.
Both green tea catechins and theaflavin from black tea inhibit the influenza virus by preventing it from attaching to cells. (Remember, the virus is most dangerous when it attaches to and "hijacks" your body cells.) The best effects were seen when the tea extracts were added directly to the virus. This means that gargling with green or black tea, and keeping the tea in contact with the virus for as long as possible, is very effective in preventing the flu.
Even more exciting is green tea's possible effect against the AIDS virus. Scientists at the Aichi Cancer Center Research Institute in Nagoya, Japan, found that ECg and EGCg both strongly inhibited the activity of HIV reverse transcriptase, working as well as the well known drug AZT. Much more research is needed, but it's a promising start.
Green Tea Strengthens the Immune System
In addition to its devastating effect on bacteria and viruses, green tea may help the body fight off invaders by stimulating the immune system to work harder and better. One study revealed that EGCg encourages the
production of interleukin-1, which in turn causes an increase in the numbers of T-cells. These T-cells then secrete chemicals that spur giant cell-eating structures called macrophages to gobble up foreign invaders.
Another study found that EGCg strengthened the effect of the immune system's B-cells, and caused them to reproduce more rapidly in mice. This is important because just a single B-cell produces thousands and thousands of antibodies, each programmed to attack specific invaders. Anything that increases the strength or number of B-cells can markedly "rev up" the power of the immune system.
Green Tea Makes Breathing Easier
Certain people carry a form of Staphylococcus aureus in their respiratory tracts; this contagious bacteria can be the source of a serious infection. In some cases the drug usually used to knock out this bacteria. Methicillin, doesn't work. If that's the case, the person is said to have Methicillin-resistant Staphylococcus aureus, or MRSA. The problem is compounded by the fact that it's difficult to detect, so the disease may go untreated and eventually spread to others. Physicians have been reluctant to use other, stronger antibiotics, because MRSA is already a "strong," resistant strain, and using even more powerful drugs may simply cause the bacteria to become even more resistant. But researchers found that inhaling a solution containing catechins led to a marked decrease in MRSA infection. In a week's time, in fact, most patients were completely free of this bacteria.
Green Tea as a "Pick-Me-Up”
Ever since eighth-century Buddhist monks discovered that drinking tea with tea ceremony set helped them remain awake during long meditation sessions, tea has been used to boost lagging energy, refresh the mind, and brighten up the mood. Its stimulating effects are due to caffeine, which is quite possibly the most popular drug in existence. Almost everyone takes in some caffeine on a daily basis via coffee, tea, cola drinks, or chocolate. (The average American tea drinker takes in about 80-100 mg of caffeine per day, while the average coffee drinker takes in twice that) And the energizing effects are familiar: Heartbeat increases, alertness improves, reaction time gets faster, and the general mood becomes more “upbeat." Some studies have also found that ingestion of caffeine improves reading speed (without increasing errors) and may even heighten intellectual activity.
The downside of caffeine is that too much can cause nervousness, chronic muscle tension, irritability, headaches, depression, and insomnia. Most healthy adults who drink moderate amounts of coffee or tea can handle 200-250 mg of caffeine a day without adverse reactions, but those who aren't used to caffeine or are especially sensitive may get jittery after just one cup of coffee.
Research into caffeine and its effect on health has been inconclusive. Although there have been some reports of links between caffeine consumption and heart disease, benign breast disease and cancer, studies have not confirmed them. In fact, a recent study conducted in Norway by the National Health Screening Service showed that caffeine was not the culprit that caused an increase of heart disease in coffee drinkers. Instead, it was due to the fact that coffee stimulates production of an amino acid called homocysteine, which causes plaque to build up on artery walls. For most people, ingesting moderate amounts of caffeine has little or no health risk. Still, many doctors advise people with heart disease, pregnant women, nursing mothers, children, and those who have trouble sleeping to avoid caffeine, or at least limit intake to 200 mg per day. For those who are strictly limiting their intake of caffeine, Opti-Pure offers a completely caffeine-free green tea extract.
Green tea may offer the best of both worlds when it comes to caffeine - just enough to provide a stimulating pick-me-up that banishes unwanted drowsiness, but not enough to trigger nervousness or sleepless nights. The average cup of green tea contains anywhere from 8 to 20 mg of caffeine, while black tea contains at least twice that amount - 40 to 60 mg. And a cup of drip coffee has a nerve-jangling 90 to 150 mg, more than half the amount of caffeine that some people should consume in a whole day. Caffeine watchers, take note: It would take at least 4 cups of the strongest green tea to equal the caffeine content of the weakest drip coffee. Still, green tea does have a "brightening" effect.
