Written by Dr. Sanjana V.B Bhms,dbrm,cdn

Founder & medical director of siahmsr wellness.in

All rights reserved with siahmsr digital healthcare[siahmsr wellness]

Reviewed by SIAHMSR medical team.

Green tea for healthy heart & brain

     Green tea is made from leaves of Camellia sinensis. They are harvested as the leaves emerge  in the beginning of early spring and processed in different ways to create white, green, oolong, and black teas. Smaller young leaves and leaf buds are used for making green tea, and the older larger leaves for the preparation of  oolong and black tea. The  buds are used for  preparing white tea. 

    Green tea is the second most consumed beverage across the globe due to its known health benefits. Green tea is used for topical application as well as for oral intake. Numerous studies have been conducted regarding its use on both ways. Researches show that it has great effect on multiple organ systems of human body such as blood ,heart, brain and skin. It  has anti- cancer properties also.

 The health effects of green tea on blood and circulatory system is very promising as it is helpful in preventing heart attacks and strokes.

Drinking  green tea could reduce the risk of coronary heart disease incidence .The  major active component of  green tea is catechins, which are a group of polyphenol antioxidants.

There are three main types of polyphenols (flavonoids, stilbenes, and lignans) Flavonoids are divided into 6 subclasses: flavonols, flavones, isoflavones, flavanones, anthocyanidins, and flavanols.

 Green tea polyphenols (GTPPs) & their good effects

 Majority of the green tea polyphenols (GTPPs) are monomeric flavanols called catechins.

The four main catechin compounds are (−)-epigallocatechin-3-gallate (EGCG), (−)-epigallocatechin (EGC), (−)-epicatechin-3-gallate (ECG), and (−)-epicatechin (EC)

Catechins can prevent the oxidation process and atherosclerotic plaque formation in Coronary heart disease. They help prevent clot formation in blood vessels to heart and brain preventing heart attack and stroke.

In addition, green tea consumption can decrease the triglycerides and cholesterol, so it can help in reducing the serum lipid concentration.

 One study has shown that green tea could help in reducing the total cholesterol, the incidence of hyperlipidemia [ high blood cholesterol], and diastolic blood pressure [1].

 The exact biological mechanisms underlying the protective effects of green tea on heart diseases is not clear. Many clinical trials have demonstrated beneficial effects of green tea on modifying the risk factors leading to heart attacks such as lowering of LDL cholesterol, triglycerides etc.

Green tea is an excellent antioxidant due to its constituents like polyphenols.

The green tea polyphenols [GTPPs] are natural compounds that have health benefits, such as reducing inflammation and helping to fight cancer.

 GTPPs have important antioxidant, immunomodulatory, and photo protective functions. They have immunomodulatory and photo protective effects on skin against UV rays of sun. Therefore green tea helps to prevent skin damage from exposure to sun’s rays [ topical applications].

Link to green tea for naturally young skin[ Read more ]

However, further studies are needed to understand the optimum dosing amounts of Green tea and GTPPs that will provide therapeutic benefits of these kinds.

Green tea contains  catechins [polyphenol] called epigallocatechin-3-gallate (EGCG). Catechins are natural antioxidants that help prevent cell damage and provide other benefits.

These substances can reduce the formation of free radicals in the body, protecting cells and molecules from damage. These free radicals play a huge role in aging and many types of diseases. The  catechin compounds in green tea can have various protective effects on neurons of brain also.

EGCG catechins  are  one of the most powerful compounds in green tea. Research has proven that it is one of the main compounds that imparts green tea its medicinal properties.

Green tea also helps to boost brain function. The key active ingredient is caffeine, which is a known stimulant included in green tea in optimum amounts. Caffeine can improve various aspects of brain function, including mood, vigilance, reaction time, and memory.

Green tea also contains amino acid L-theanine, which can cross the blood-brain barrier.

The role green tea in improving heart health as well as brain health has been proven by numerous studies beyond doubt. However how much green tea must be taken to achieve these effects needs clarification by further extensive studies. 

 How much green tea intake is recommended for better health?

It is recommended that 1-2 cups of green tea is beneficial to the body without any harmful side effects.

Excessive usage is not suggested as one or two animal studies in mices have given adverse, harmful effects of green tea extract in animals. No human studies have been found to be harmful if consumed in moderate amounts.

Green tea can cause mild side effects due to caffeine. These can include anxiety, tremors, irritability, and sleeping problems if you’re sensitive to caffeine or take excess doses.

Larger doses of green tea extract can cause liver problems. The negative effects are dependent on how much green tea extract you consume each day.

Mild to moderate doses of green tea are beneficial and safe to your body in various ways.

Drug interactions of green tea

     Green tea may affect medicines such as nadolol, a beta-blocker used for high blood pressure and heart problems. It may keep nadolol from lowering your blood pressure as much as it should. Green tea contains small amounts of vitamin K and it may decrease how well blood thinner medicines work. Hence  patients using beta blocker drugs, and blood thinners like aspirin, clopidogrel etc. are not advised to take green tea.

      Green tea is advised in people having no heart disease and not taking medications for it. The role of green tea is prevention of risk factors  [ cholesterol ,triglycerides,high blood pressure] leading to clot formation and stroke in  populations .

References

1.     https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4843789/

2.     https://www.nature.com/articles/srep24353

3.     https://plants.ces.ncsu.edu/plants/camellia-sinensis/

4.     https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=19&contentid=greenteaextract#:~:text=Green%20tea%20can%20cause%20side,other%20drinks%20that%20have%20caffeine.