ABOUT GREEN TEA
Green tea is “non-fermented, non-oxidative, less processed and low calorie” form of beverage. It is made from CAMELLIA SINENSIS leaves. It is using as dietary supplement. It is supposed to be as “healthful beverage” due to its health preventive benefits. It is supposed to be rich in antioxidants (especially in polyphenolics compound) because it is produced without fermentation which in turn prevent oxidation of polyphenolic compounds.
CHEMICAL COMPOSITION
Chemical constitution of green tea includes steroids, tannins, saponins flavonoids (kaempferol, quercetin, myricetin), phenols, alkaloids, polyphenols, glycosidic derivatives (cartenoids, quinic acid, chlorogenic acid, trigalloyl glucose), methylxanthin, caffeine, theophylline, theobromine, lignin, theanine (derived from amino acid) and minerals (aluminum and manganese). Polyphenols consists of mostly CATECHINS like Epigallocatechin gallate (EGCG), Epigallocatechin (EGC), Epicat-3-gallate and Epicatechin (EC).
PHARMACOLOGICAL ACTIVE INGREDIENT OF GREEN TEA
Epigallocatechin gallate (EGCG) is considered as pharmacological active ingredient of green tea.
WHICH COMPONENT OF GREEN TEA ATTRIBUTES BOTH BENEFICAL AND ADVERSE EFFECTS?
Polyphenolic catechins are responsible for both beneficial and adverse effects of green tea. Among them EGCG is very important and pharmacologically active one and supposed to be responsible for induction of oxidative stress in liver.
AVAILABLE FORM OF GREEN TEA
Green tea is available as dry leaves, in powdered form (matcha), in capsular form as concentrated extract, as pill and in liquid form.
HEALTH BENEFITS OF GREEN TEA
There are insufficient clinical trials or scientific evidence which support the benefit claims of green tea in human. However, green tea with limited in vitro or animal studies evidences is supposed to be beneficial tool against many illnesses which are listed as follow
1. It reduces the risk of certain types of cancer and cardiovascular disease.
2. It is supposed to promote oral health and hygiene.
3. It controls body weight because of its fat oxidation potential which enhance metabolism and burns the fat faster so it is used frequently by the people who are aiming for weight loss. On contrary to this claim, a meta-analysis which is published in INTERNATIONAL JOURNAL concludes that” green tea has very slight effect in weight reduction.”
4. It is supposed to be helpful in diabetes because it controls obesity.
5. It prevents atherosclerosis and lowers cholesterol due to richness in catechins (antioxidant).
6. It is supposed to improve cellulitis, asthenia, diarrhea, bronchitis and asthma.
GREEN TEA AND LIVER TOXICITY
Long term use or concentrated form of green tea can cause liver toxicity is one of the most emerging problem nowadays.
Now the question is that conventional green tea pose the same risk of liver toxicity as compare other available forms of green tea?
Conventional green tea is consider safe to drink when consumed in normal quantity (1- 2 cups/ day) as compare to other forms of green tea such as powder form, concentrated green tea extract in capsular form and tablet which are mostly used for weight loss. The reason behind is that we are unaware about the fact what else toxic substances or excipients like solvent or pesticides residue are present in concentrated green tea extract during manufacturing. With which ingredient concentrated green tea is adulterated for quick weight loss. The liver toxicity cases with conventional infusion are less as compare to concentrated green tea extract.
GENDER AND GREEN TEA HEPATOTOXICITY
Cases of liver toxicity in women are more as compare to men so we can say that women are more susceptible to liver toxicity with green tea.
GENETIC VARIATION AND GREEN TEA HEPATOTOXICITY
Sometime hepatotoxicity with green tea is due to genetic variation. It may affect one person while other one is not affected with it.
SYMPTOMS OF LIVER TOXICITY WITH GREEN TEA
Abdominal pain, fatigue, dark urine and jaundice.
POSSIBLE MECHANISM OF ACTION OF HEPATOTOXICITY WITH GREEN TEA
There is no exact scientifically proven mechanism of action which can be illustrated but possible mechanism of action is as follow,
1. It may be due enzymatic reactions which elevates liver enzymes level and through cellular and metabolic way causes necrosis of liver and results in liver failure.
2. According to another theory EGCG (polyphenol) in green tea attacks liver mitochondria and causes hepatitis (inflammation of liver) and may lead to liver failure.
3. It may be due to immune-allergic reaction which causes necrosis of liver.
ACCORDING TO RESEARCH PUBLISHED IN “GASTRO HEP” ABOUT GREEN TEA IS THAT, “Green tea consumption causes the inflammation of liver and may even lead to liver failure “.
ACCORDING TO RUTGERS RESEARCH PUBLISHED IN THE JOURNAL OF DIETARY SUPPLEMENTS IS THAT,” too much consumption of green tea beverage is not good to your liver.”
CONCLUSION
There are many case histories of patients clearly indicating a casual relation between hepatotoxicity and green tea consumption especially with concentrated green tea extract. In some cases, transplantation of liver occurred. However, it is difficult to predict which component of green tea is responsible for liver toxicity. Whether it is due to EGCG which induce oxidative stress in liver or due to adulterated substance present in green tea extract or due to metabolic reaction or may be due to presence of any toxic substance. Concentrated green tea extract consumption must be avoided and drinking of conventional green tea infusion should be in limit.
