Green Tea (First grade) கிரீன் டீ (முதல் தரமானது)
Main article: Health effects of tea
Brewed, regular green tea
Nutritional value per 100 g (3.5 oz)
Energy 4 kJ (0.96 kcal)
Thiamine (B1) 1%0.007 mg
Riboflavin (B2) 5%0.06 mg
Niacin (B3) 0%0.03 mg
Vitamin B6 0%0.005 mg
Vitamin C 0%0.3 mg
Calcium 0%0 mg
Iron 0%0.02 mg
Magnesium 0%1 mg
Manganese 9%0.18 mg
Potassium 0%8 mg
Sodium 0%1 mg
Other constituents Quantity
Water 99.9 g
Caffeine 12 mg
Link to Full USDA Nutrient Report
μg = micrograms • mg = milligrams
IU = International units
†Percentages are roughly approximated using US recommendations for adults.
Regular green tea is 99.9% water, provides 1 kcal per 100 mL serving, is devoid of significant nutrient content (table), and contains phytochemicals such as polyphenols and caffeine.
Numerous claims have been made for the health benefits of green tea, but human clinical research has not found good evidence of benefit. In 2011, a panel of scientists published a report on the claims for health effects at the request of the European Commission: in general they found that the claims made for green tea were not supported by sufficient scientific evidence. Although green tea may enhance mental alertness due to its caffeine content, there is only weak, inconclusive evidence that regular consumption of green tea affects the risk of cancer or cardiovascular diseases, and there is no evidence that it benefits weight loss.
A 2020 review by the Cochrane Collaboration listed some potential adverse effects of green tea extract including gastrointestinal disorders, higher levels of liver enzymes, and, more rarely, insomnia, raised blood pressure, and skin reactions.
It has been suggested that it may inhibit cancer development and growth by preventing “cell damage” based on its antioxidant and anti-inflammatory properties.
However, Green tea interferes with the chemotherapy drug bortezomib (Velcade) and other boronic acid-based proteasome inhibitors, and should be avoided by people taking these medications.
A meta-analysis of observational studies reported an increase in one cup of green tea per day was correlated with slightly lower risk of death from cardiovascular causes. Green tea consumption may be correlated with a reduced risk of stroke. Meta-analyses of randomized controlled trials found that green tea consumption for 3–6 months may produce small reductions (about 2–3 mm Hg each) in systolic and diastolic blood pressures. A separate systematic review and meta-analysis of randomized controlled trials found that consumption of 5-6 cups of green tea per day was associated with a small reduction in systolic blood pressure (2 mmHg), but did not lead to a significant difference in diastolic blood pressure.
Green tea consumption lowers fasting blood sugar but in clinical studies the beverage’s effect on haemoglobin A1c and fasting insulin levels was inconsistent.
Drinking green tea or taking green tea supplements decreases the blood concentration of total cholesterol (about 3–7 mg/dL), LDL cholesterol (about 2 mg/dL), and does not affect the concentration of HDL cholesterol or triglycerides. A 2013 Cochrane meta-analysis of longer-term randomized controlled trials (>3 months duration) concluded that green tea consumption lowers total and LDL cholesterol concentrations in the blood.
A 2015 systematic review and meta-analysis of 11 randomized controlled trials found that green tea consumption was not significantly associated with lower plasma levels of C-reactive protein levels (a marker of inflammation).
There is no good evidence that green tea aids in weight loss or weight maintenance.
Potential for liver toxicity
Excessive consumption of green tea extract has been associated with hepatotoxicity and liver failure. In 2018, a scientific panel for the European Food Safety Authority reviewed the safety of green tea consumption over a low-moderate range of daily EGCG intake from 90 to 300 mg per day, and with exposure from high green tea consumption estimated to supply up to 866 mg EGCG per day. Dietary supplements containing EGCG may supply up to 1000 mg EGCG and other catechins per day. The panel concluded that EGCG and other catechins from green tea in low-moderate daily amounts are generally regarded as safe, but in some cases of excessive consumption of green tea or use of high-EGCG supplements, liver toxicity may occur.[