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Green Tea Extract: what it is, beneficial effects, side effects and more

As you wake up in the morning, the first thing that comes to your mind is a cup of hot steaming cup of tea. It freshens you up, does away with all the drowsiness and gets back the alertness which you seem to lose while sleeping. 


But what about the green tea? Green tea is also made from the plant camellia sinensis, but the process of making the green tea differs from that of black tea. All such processes which include withering of the leaves and the buds, collected from the tea plants and the oxidation process of the same are avoided while making the green tea.

As of many things, the credit for the discovery and use of green tea also goes to the Great Nation China. Now it has spread all over the world. Lately it has come to prominence due to a strong belief that green tea extract has many beneficial effects on health.

Extensive research is going on to establish the health benefits of drinking green tea extract. The components of green tea extract have been identified and the potential effects of the same are being researched in various laboratories.

Composition of the green tea extract


  • Epigalocatechin
  • Epicatechin Gallate
  • Epicatechins
  • Flavonoids


  • Kaempferol
  • Quercetin
  • Myricetin

Green tea extracts can be availed over the counter in various forms such as powder, liquid, capsules and tablets. Caffeine content in green tea extract can be up to 17.4% of the total weight of green tea extract. If you search for the decaffeinated version of green tea, you will of course get it.

Nutritional Facts

Quantity     100 grams

Energy content          0.96 Kcal

Protein                       0.2 grams


Thiamine ( vitamin B1 )       0.007 mg

Riboflavin ( vitamin B2 )      0.06 mg

Niacin ( vitamin B3 )            0.03 mg

Vitamin B6                          0.005 mg

Vitamin C                           0.3 mg


Iron                                    0.02 mg

Magnesium                        1 mg

Manganese                       0.18 mg

Potassium                          8 mg

Sodium                               1 mg


Caffeine                             12 mg

Water                                 99.9 grams

Possible side effects of green tea extract

  • Gastrointestinal dysfunctions
  • Increase in the levels of liver enzymes
  • Insomnia
  • High blood pressure ( rare occurrence )  
  • Skin eruptions

Research results on the effects of green tea extract on various diseases


No conclusive evidence has been found linking the consumption of green tea to cancer remission. However people who are on chemotherapy should avoid taking green tea extract as it interferes with the boronic acid based drugs.

Cardiovascular ailments

Some studies have found connections of consuming green tea regularly on reduction of blood pressure and risk of suffering from strokes.     

Regulating blood sugar                     

By consuming green tea extract on a regular basis, there may be some reduction in fasting sugar.

Cholesterol regulation

The green tea extract decreases total cholesterol levels and LDL cholesterol levels but has no effect in reducing the HDL cholesterol levels.


Green tea extract has not shown any improvement in inflammatory conditions.

Possible health benefits of consuming green tea extract regularly

Green tea is a bioactive phytochemical which contains many bioactive compounds. The polyphenols contained in the green tea extract are thought to have many health benefits such as fighting inflammatory conditions and even fighting cancerous cells.

Epigallocatechin-3-gallate or EGCG found in green tea extract is a natural antioxidant. Antioxidants are very useful for health as it eliminates the free radicals from the body. Free radicals cause damage to the tissues and the organs, making oxidative stress. Free radicals stimulate the aging process. By consuming green tea extract regularly, the anti-aging process can be stopped.

The other useful contents of the green tea extract are various minerals and vitamins which have many beneficial effects on the human body.

Effects on cognitive behaviors

Green tea extract contains a good amount of caffeine. Caffeine is a well known stimulant. One of the good things with green tea extract is that it contains optimum amount of caffeine which is much less than the caffeine content in coffee. Thus by taking green tea extract you would get all the good responses without having the jittery effects.

Various studies have been able to establish that caffeine can improve cognitive functions of the brain such as alertness, moods, memory, reaction time and vigilance.

Green tea extract has another vital vitamin called L-Theanine. It has the ability of crossing the blood-brain barrier. By enhancing the functioning of the neurotransmitter GABA it helps in reducing anxiety.

Effects of green tea extract on weight loss

Though not yet fully established through research, green tea has possible effects on weight loss also. Green tea extract has a thermogenic effect on the body by which it increases the body heat and metabolism. Both the above two processes may help reduce weight. But the results are often confusing. While some studies have confirmed its weight loss properties, others have indicated no such beneficial results of consuming green tea extract regularly.

Protection from aging of the brain

Green tea extract contains various catechin compounds. Such compounds may have some positive effects on the brain. Parkinson’s disease is caused due to decline of neurons such as dopamine. Green tea extract may stimulate the production of dopamine stopping the progress of the disease.

Concluding Remarks

From the above discussions we find that green tea extracts are a popular beverage in China and the East Asian countries of the world. But gradually the consumption of green tea extract has picked up in other countries too due to the belief that green tea extract has many health benefits.

Though researchers have not been able to find any significant beneficial results of consuming green tea extract regularly, some beneficial effects have of course been established.

However when consumed in limited quantities, no significant side effects have been reported. The optimum amount of caffeine content has many positive health benefits without having any jittery effects which is found after consuming coffee which has a sizable amount of caffeine.

Green tea extract can safely be included as a regular beverage in limited amounts.