It was reportedly discovered by a Chinese emperor some 40 centuries ago. And, legend has it, the discovery was purely by accident. But that coincidental discovery has improved the health of people around the world, who have turned to green tea in particular to help soothe their pains, improve their digestion, alleviate their depression, boost their immune system, and perhaps even lengthen their lives.

But what is it that makes green tea so beneficial to human health?

The Ingredients of Success

Green tea is actually made up of a variety of ingredients. These include caffeine, vitamins, minerals, and oils. However, the most important ingredients are the polyphenols, especially one called EGCG, which is believed to improve health.

In fact, it is the polyphenols which make green tea so much more effective than other beverages in fighting disease and illness.

Green Tea and Cholesterol

There have been some intriguing studies indicating that green tea can be effective in the fight against high cholesterol. Specifically, the beverage reduces "bad" cholesterol and boosts "good" cholesterol, improving an individual's overall cholesterol profile.

In addition, green tea appears to lower overall cholesterol levels, helping to reduce one's risk of developing heart disease.

Similarly, green tea enhances cardiovascular health by improving the consistency of platelets in the blood.

Researchers have also found that green tea appears to protect against oxygen-induced damage to bad cholesterol.

Drinking green tea also seems to enhance antioxidant processes in the bloodstream.

Effect of Green Tea on Blood Fats

In recent years, much attention has been focused on blood fats and the effects of diet and exercise on their consistency. In an interesting study conducted at the Department of Public Health at the National Defense Medical College in Saitama, Japan, researchers S. Kono, K. Shinchi, N. Ikeda, F. Yanai, and K. Imanishi investigated the impact of green tea consumption on blood fats, also known as serum lipids.

The study was published in an article entitled, "Tea Consumption and Serum Lipid Profiles: a Cross-Sectional Study in Northern Kyushu, Japan."

Specifically, the researchers examined the correlation between green tea use and the serum lipid concentrations of more than 1300 men who underwent retirement health exams at the Self-Defense Forces Fukuoka Hospital between 1986 and 1988.

The researchers factored out variables such as alcohol use, use of tobacco, exercise levels, body mass index, and rank.

They then discovered that the more green tea a patient drank, the lower his serum cholesterol levels. Men who drank nine or more cups of tea each day had total cholesterol levels that were eight mg/dl lower than those who drank two or fewer cups a day.

The serum cholesterol levels seemed to also decrease for men who ate a great deal of rice and soy beans, and increase for those who ate more Western foods.

However, adjusting for these additional diet variables did not seem to affect the correlation between green tea use and total cholesterol levels.

Additional Evidence from the Animal Kingdom

It's been said that there is a definite link between diet and exercise and coronary heart disease. Therefore, anything in the diet that improves serum lipid profiles should reduce the incidence of heart problems.

It's also known that green tea contains phytochemicals that work to decrease serum cholesterol as well as triglycerides.

In one animal study, 45 rats were subjected to a variety of treatments, including green tea. The study showed that consuming green tea improved the serum lipid profile by reducing total cholesterol, bad cholesterol, and trans fats. In addition, liver fat content decreased in rats that received a large amount of green tea.

Other Positive Effects of Green Tea Drinking

The polyphenols found in green tea may have some additional positive health effects. For instance, a number of animal and test tube studies indicate that these chemicals may have a substantial anti-cancer effect, especially in inhibiting the spread of melanoma, or skin cancer cells.

Green tea has also been linked to a reduction in oral cancers and dental cavities.

In addition, green tea may stimulate the production of immune system cells.

As a result, it can help the body fight bacteria, leading to improved overall health. In fact, one study showed that drinking ten or more cups of green tea each day could improve blood test results, protecting the body against liver damage.

How Much Green Tea is Enough?

Of course, you might be wondering how much green tea must be consumed in order to have a positive impact on health. In Asian nations, the typical tea drinker consumes about three cups each day-enough to provide as much as 320 mg of polyphenols.

Nevertheless, some studies indicate as many as ten cups each day are needed in order to really make a difference in cholesterol levels and overall health.

Possible Side Effects

It should be noted that there can be some negative side effects associated with green tea consumption. While green tea is a relatively healthy drink, those who consume several cups of it each day may experience anxiety and insomnia brought on by the caffeine found in the beverage.

Drinking green tea may also lead to iron deficiencies, since iron absorption in women may be reduced as much as 26 percent when green tea is consumed with a meal.

In addition, some drugs can interfere with green tea's positive effects. Therefore, before switching to a diet rich in green tea, it may be best to check with a physician to determine if such a diet is right for you.

Looking to the Future

The forecast for green tea appears to be bright-as far as public health is concerned. Study after study seems to indicate that green tea can reduce cholesterol levels, combat cardiac disease, boost the immune system, and reduce the risk of cancer.

While additional study is needed in order to effectively harness all the benefits of green tea, it appears, for the moment, that simply adding a few cups of the brew to your daily diet can yield impressive health benefits.