Green tea contains a high proportion of catechins, which have been extensively researched scientifically. Catechins combat free oxygen radicals, protecting the body's cells and reducing inflammation. This effect means that it can support our health in many ways.
For thousands of years, green tea has not only been consumed as a beverage, but has also been used in traditional Chinese and Indian medicine as a stimulant, diuretic, a means of controlling bleeding and healing wounds, and improving heart health.
Other, less well-known traditional uses for green tea include regulating blood pressure, lowering cholesterol, improving digestion, increasing mental acuity, and preventing diabetes.
Medical professionals agree that a daily dose of green tea promotes health in several ways.
Whether you drink green tea daily, take a high-quality dietary supplement containing green tea as an active ingredient, or combine the two methods above for the best possible results, green tea is fantastic for your health.
Green tea contains high levels of polyphenols, which are known as catechins in tea and have been extensively researched scientifically. Of the six catechins in green tea, epigallocatechin-3-gallate—also known as EGCG for short—is the most active. The antioxidant activity of EGCG is around 25-100 times higher than that of vitamins C and E.
The catechins in green tea combat free oxygen radicals, protect and repair cells, and reduce inflammation.
Since inflammation is one of the causes of many age-related diseases, green tea could have a wide range of applications in disease prevention.
Results from animal studies show that the polyphenols in green tea promote the repair of damaged DNA. Since such damage can lead to cancer, protective agents such as green tea can play an important role in cancer prevention.
One capsule of green tea extract provides about as much polyphenols and EGCG as five cups of green tea. The active ingredients in green tea extract are 60-90% better absorbed into the bloodstream and are more bioavailable than green tea as a beverage.
The studies and scientific evidence on green tea are overwhelming. Most of the benefits are based on the antioxidants in green tea, called catechins. These protect cells from free radicals, which can damage DNA and contribute to cancer, artery blockage, and blood clots.
Due to minimal processing—the leaves are steamed instead of fermented—the catechins in green tea are unique and contain more EGCG in concentrated form, which is the active ingredient that many studies emphasize as the driving force behind the benefits of green tea.
The effects of green tea on cancer and heart disease appear very promising, and many people report life-changing benefits from daily consumption.
Although studies on how green tea affects cancer cells are still in their infancy, human trials show that it prevents cells from developing cancer.
The EGCG contained in green tea regulates and inhibits cancer growth by killing cells that grow abnormally.
- In Japan, a study was conducted on 500 women with stage I and II breast cancer, which found that increased consumption of green tea before and after surgery significantly reduced the risk of recurrence.
- A further analysis of 22 studies on the correlation between green tea and lung cancer found that increasing green tea consumption by two cups per day reduced the risk of lung cancer by 18%.
The ability of green tea to prevent cancer is so well documented that green tea is being tested as a potential cancer therapy in new studies.
Green tea can protect former and current smokers from lung cancer in particular. Its protective effect against lung cancer is extremely important, as studies have found that former smokers have an even higher risk of lung cancer than previously thought.
In a 2009 study of 26 men diagnosed with prostate cancer, those who took four capsules of green tea extract per day showed a significant decrease in certain markers that indicate the progression of prostate cancer.
Each dose of four capsules provides the equivalent of 12 cups of brewed green tea. The treatment period ranged from 12 days to 73 days, with an average duration of 34.5 days.
Study results published in the Proceedings of the National Academy of Sciences show that antioxidant polyphenols in green tea can help people suffering from arthritis by reducing the incidence and severity of the disease.
EGCG protects against cartilage destruction and reduces joint swelling and pain.
Therefore, many scientists and medical professionals recommend green tea as a legitimate treatment for arthritis.
Oxidative damage caused by free radicals plays a crucial role in age-related cognitive decline and neural loss due to neurodegenerative diseases.
However, cell death can also be caused by inflammation or by an accumulation of harmful proteins, such as amyloid beta, the biochemical hallmark of Alzheimer's disease.
The antioxidant and anti-inflammatory effects of catechins in green tea can also be helpful in this regard.
"There is now a great deal of scientific evidence, both experimental and epidemiological, showing that certain natural compounds, such as catechins from green tea, improve age-related cognitive decline and have neuroprotective effects in animal models of Parkinson's disease, Alzheimer's disease, stroke, Huntington's disease, amyotrophic lateral sclerosis (ALS), and other brain diseases," says Bradford L. Frank, MD, MPH, MBA, clinical assistant professor at the University of Buffalo School of Medicine and Biomedical Sciences.
A population study of more than 1,000 Japanese adults aged 70 and older showed that regular consumption of more green tea was associated with a lower incidence of cognitive impairment.
Compared to test subjects who drank three or fewer cups per week, those who drank just one cup per day showed a 38% decline in cognitive impairment. This significant protective effect was not observed with black tea or coffee.
Researchers believe that green tea lowers cholesterol levels by inhibiting the absorption of cholesterol in the digestive tract and increasing the rate at which it is excreted.
However, your body needs cholesterol to build cell membranes, insulate nerve fibers, and form hormones. Therefore, green tea helps prevent LDL cholesterol from converting into its much more dangerous oxidized form.
Oxidized LDL is one of the main factors in the development of atherosclerosis, the build-up of plaque that blocks the arteries, as LDL becomes sticky and attaches itself to the artery walls. This increases the risk of heart attack and stroke. The amazing antioxidant effect of green tea protects against this and helps keep your arteries clean.
- A 2003 study shows that green tea capsules, in combination with a diet low in saturated fat, can help control cholesterol levels. The study examined 240 adults who all had mild to moderately elevated cholesterol levels at the start of the study.
- The results of the study showed that all those who took green tea extract in capsule form for 12 weeks had a greater reduction in LDL (“bad”) cholesterol than participants who took a placebo capsule during the same period.
Catechins, the most important polyphenolic compounds in green tea, have vascular protective effects due to several mechanisms, including antioxidant, anti-inflammatory, antithrombotic, growth-inhibiting, and lipid-lowering effects.
Green tea and EGCG have been shown to reduce atherosclerosis and improve arterial elasticity and endothelial function.
Regular consumption of green tea is associated with a reduced risk of cardiovascular diseases such as strokes and heart attacks. Catechins in green tea also regulate the elasticity of blood vessels.
A Japanese study published in the Journal of the American Medical Association shows a significant reduction in deaths from cardiovascular disease among people who drink green tea.
- The study showed that people who drank more than 5 cups per day had a 16% lower mortality rate and mortality rate associated with cardiovascular disease over an 11-year test period compared to people who drank less than one cup per day.
- They also found that green tea was particularly helpful in preventing strokes, largely due to its antioxidants and their ability to prevent clogged arteries.
Catechins, antioxidant polyphenol compounds, have a powerful effect on the immune system.
Research published by Brigham and Women's Hospital in 2003 showed that theanine, which is found in green tea, increased the activity of gamma delta T cells, which are part of our adaptive and innate immunity.
The study examined a group of coffee drinkers and a group of tea drinkers who each consumed 600 ml of their beverage per day. Blood samples taken four weeks later showed quite clearly that the production of these antibacterial proteins was five times higher in the tea drinkers.
As one of the most important benefits of green tea, EGCG was also highlighted in a study in the Journal of Allergy and Clinical Immunology because it can prevent infections, including the HIV virus.
- EGCG binds to the CD4 receptors of T cells in the immune system, preventing HIV from doing the same and reducing the risk of infection.
- Although it is still too early to call green tea a cure for HIV, an Egyptian study has shown that combining antibiotics with green tea greatly increases the effectiveness of the antibiotic.
- When tested against 28 disease-causing microorganisms, green tea enhanced the antibacterial power in every single case.
Over a period of three months, a group of healthy adults took either a proprietary formula of green tea extract or a placebo capsule twice a day. At the end of the study, those who took the green tea supplement reported fewer cold and flu symptoms and fewer sick days.
Green tea fights acne in several ways. Its antibacterial properties attack and kill acne bacteria, while the anti-inflammatory effects of green tea reduce swelling and redness.
Antioxidants fight free radicals, which damage the skin and make it more prone to acne, and also regulate hormone levels to prevent further breakouts.
Both green tea and green tea extract capsules have been shown to combat obesity and lower LDL cholesterol—both factors that ultimately lead to a reduced risk of heart disease and diabetes.
The polyphenols in green tea are extremely useful in dissolving triglycerides, a substance in the liver and small intestine that consists mainly of sugar and fat, which is believed to be the reason why green tea promotes fat burning.
EGCG also stimulates the metabolism and accelerates weight loss. Combined with the caffeine in green tea, it causes the central nervous system to release fat into the bloodstream as fuel, burning body fat.
Antibacterial agents from green tea are also used by the body to kill the bacteria that cause plaque to form on the teeth.
Research findings from the Journal of Periodontology have also shown that every cup of green tea reduces the signs of gum disease. Green tea also contains fluoride, which protects against tooth decay.
In 2007, Dr. Orhan Aktas from the Institute of Neuroimmunology conducted a study to determine how green tea can help people suffering from multiple sclerosis.
While patients currently do not have many options for preventing tissue damage and disability, he discovered that the flavonoid EGCG, which is found in green tea, can have a huge impact on multiple sclerosis.
He concluded that EGCG can directly protect against neuronal injury in living brain tissue and that components of EGCG could represent a new therapeutic option for the treatment of MS by combining anti-inflammatory and neuroprotective effects.
A recent report published in the journal Phytomedicine provides significant evidence that the enzymes contained in green tea can protect brain cells from damage.
Another study conducted by the University of South Florida looked at the effects of antioxidant EGCG. It was found to be a protein blocker that prevents the chemical reactions that can lead to nerve damage, which in turn causes Alzheimer's and Parkinson's disease.
Methylated EGCG has been shown to block a cell receptor involved in allergic reactions. By blocking the production of histamine and immunoglobulin E (IgE), two compounds that play a key role in triggering and maintaining allergic reactions, EGCG could well be the substance that prevents people from getting watery eyes, runny noses, and coughs.
The reason for its anti-aging effect is again due to the antioxidants, which prevent cell oxidation and cell damage that make a person look older than they are.
The study results regarding this benefit of green tea are mixed, as new research suggests that you can only reap the full benefits if green tea is applied topically to the skin.
However, many people have observed that high-quality green tea extracts have a positive effect on their skin, making it softer and younger-looking.
To really benefit from the advantages of green tea, you would have to drink at least 5 cups a day. However, it is important to choose a high-quality green tea that actually has a high EGCG content—because not all green teas are the same.
Drinking that much green tea every day is not possible for most people, and not everyone likes the taste of green tea—not to mention the fact that drinking large amounts of tea means you have to go to the bathroom constantly.
Green tea capsules are therefore the ideal alternative to conventional green tea. With green tea capsules, you also know exactly how much EGCG you are consuming.
High-quality capsules contain a green tea extract with a total polyphenol content of 98% and an EGCG content of 45%, which corresponds to approximately 300mg of EGCG per capsule (this information may vary depending on the capsule content).
Experts recommend consuming at least 250-350 mg of EGCG per day to reap the maximum benefits. This corresponds to 1-2 capsules of a good green tea product. In addition to valuable catechins such as EGCG, green tea capsules also contain many valuable polyphenols (plant compounds).
When buying green tea capsules, be sure to check their polyphenol and EGCG content. If this is not stated on the packaging, it is probably not a high-quality green tea extract.
Many green tea capsules contain caffeine. Therefore, choose a decaffeinated green tea product if you are sensitive to caffeine and do not want to experience the associated side effects, such as increased heart rate, elevated blood pressure, anxiety, and worsening ulcer symptoms.
