Tea is one of the world’s most beloved beverages.
From the Camellia sinensis plant, tea is consumed as green, black, or Oolong tea.
The first green tea was sent from India to Japan in the 17th century.
About 2.5 million tons of tea leaves are produced annually throughout the world. About 20% of those are green tea.
Fresh leaves are immediately steamed to stop fermentation.
The steaming stops the enzymes that breaking down color pigments in the leaves, so the tea remains green.
Then the leaves are dried to be used in tea. These processes preserve the antioxidants in green tea (1).
The benefits of green tea are now becoming well-known as more research confirms them.
What Is the Healthiest Green Tea?
Many believe that matcha is the healthiest green tea to consume.
The entire green tea leave is ground into a powder and then whisked into hot water.
This allows one to consume the entire tea leaf, rather than steeping and straining the tea leaves.
It is believed that this confers more health benefits to the consumer.
Matcha is popular in Japan but has been spreading around the world.
Is It Safe to Drink Green Tea Everyday?
Generally, consumers can enjoy green tea daily. Pregnant women should limit caffeine consumption to 300 mg or less per day.
One 8 oz serving of green tea contains about 30-50 mg of caffeine (2).
As such, many people can drink green tea daily without any negative consequences.
12 Things That Happen to Your Body When You Drink Green Tea
1. Powerful Antioxidants
Many of the health benefits green tea offers come from the antioxidants found in the leaves.
The epigallocatechin gallate (EGCG) in green tea is one of the most powerful compounds found in the beverage.
Studies have found that EGCG can improve heart health, diabetes, and is anti-inflammatory (3).
Many of the health benefits attributed to drinking green tea are due to the antioxidant content of the beverage.
2. May Help with Weight Loss
In recent years, green tea has been tied to weight loss. And research is now confirming that this may be true.
Green tea may boost metabolism, helping with weight loss efforts.
It is thought that the EGCG and caffeine found in green tea may work together to prevent the development of obesity (4).
Future research is needed to examine exactly how this occurs.
3. Keeps Hearts Healthy
One of the health benefits of green tea may be keeping your heart in tip-top shape.
Studies have shown that green tea may improve both the total cholesterol and LDL or “bad” cholesterol levels in tea drinkers, thereby preventing heart disease (5).
One review found that half of the studies included in its consideration demonstrated positive effects of green tea on heart disease risk profiles (6).
Another study found that moderate tea drinkers demonstrated a slower progression of calcium build-up in arteries, as well as reduced risk for cardiovascular events (7).
Another study followed 40,000 participants for 11 years and found that those who drank at least 5 cups of green tea daily had a lower risk of dying, particularly from heart disease (8).
4. May Aid with Fat Burning
While green tea may help with weight loss overall, it has also been shown to specifically help burn fat.
A 2005 study found that ECGC and caffeine can increase fat burning in subjects (4).
Another study found that two servings of green tea daily reduced abdominal fat in participants (9).
More research is needed to determine how green tea aids with fat loss.
5. Supports a Healthy Immune System
Another benefit of green tea is its support of the immune system.
In fact, several kinds of immune cells in the adaptive and innate immune systems are impacted by EGCG and green tea (10).
More research is needed to determine how drinking green tea works as immune support.
6. Benefits Brain Health
Green tea may also help another vital organ- the brain. Green tea contains a compound, L-theanine.
This amino acid, L-theanine, has been shown to improve brain function.
This amino acid crosses the blood-brain barrier and enhances a neurotransmitter, GABA, which has been shown to improve anxiety (11).
Additionally, the polyphenols found in green tea have been shown to slow the aging process in the brain and may help protect the brain against disorders like Alzheimer’s and Parkinson’s diseases (12).
7. May Prevent Cancer
Several studies have shown a link between green tea consumption and a reduced risk of certain types of cancer.
Studies have found that women who consumed more green tea cut their risk of developing breast cancer by 20-30% (13).
A 2015 study found that green tea drinking was linked with a 42% less risk of developing colorectal cancer (14).
Another study found that men who consumed green tea had a decreased risk of developing prostate cancer (15).
More information is needed on how green tea impacts different types of cancer and how much tea to drink for optimum benefits.
8. Stave Off Diabetes
Green tea may also help to prevent the onset of diabetes.
Studies have shown that green tea may help insulin sensitivity, and may decrease blood sugar levels, including fasting blood sugar and hemoglobin A1c (16).
The hemoglobin A1c is a marker that shows the three-month average of blood sugar levels.
One study found that participants who drank 6 or more cups of green tea per day had a 42% lower risk of developing type 2 diabetes (17).
There seems to be a link between green tea consumption and a lower risk of diabetes.
More research is needed to understand how and why this happens.
9. May Lower Cholesterol
Aside from overall heart health, green tea may impact our cholesterol levels.
Green tea has been linked to reductions in LDL or “bad” cholesterol (18).
No reductions were seen in total cholesterol, nor HDL, or “good” cholesterol.
More research is needed to understand the link between green tea and cholesterol.
10. Reduces Stroke Risk
Drinking either green tea or coffee has been linked to a reduced risk for stroke.
A 2013 study showed that drinking at least one cup of green tea daily positively impacted stroke risk (19).
More studies are needed, but this may be another health benefit of the beverage.
11. Live Long with Green Tea
Want to live a long life?
Perhaps you should brew a cup! One study followed over 40,000 adults for 11 years and found that those who drank 5 or more cups of green tea daily were less likely to die from heart disease, stroke, and all causes (20).
Another study followed 14,000 older adults for 6 years and found that those who drank the most green tea had a 76% decrease risk of dying of all causes (21).
12. Healthy Skin
Can drinking green tea improve your skin?
A study published in 2007 found that green tea slowed the growth of skin cells and a reduction in the proliferating cell nuclear antigen levels in animal models that are a hallmark of inflammatory skin disorders like dandruff or psoriasis (22).
This indicated that green tea many improve conditions with red, inflamed, and flaky skin.
Others believe that a diet rich in antioxidants, like those found in green tea, can lead to overall healthier skin.
Green tea is one of the world’s most popular and oldest beverages. It has been consumed for centuries for its refreshing taste and a host of health benefits.
Recently, scientific study has confirmed many health benefits from consuming green tea, from help with weight loss, anti-aging, heart health, and cancer prevention.
More research is needed to discover exactly how green tea impacts our health, and the optimal amount to consume.
Until then, it is safe for most people to drink at least one cup daily.
- Chacko, Sabu M, et al. “Beneficial Effects of Green Tea: A Literature Review.” Chinese Medicine, vol. 5, no. 1, 2010, p. 13., doi:10.1186/1749-8546-5-13.
- Heckman, Melanie A., et al. “Caffeine (1, 3, 7‐Trimethylxanthine) in Foods: A Comprehensive Review on Consumption, Functionality, Safety, and Regulatory Matters.” Wiley Online Library, John Wiley & Sons, Ltd, 5 Apr. 2010, onlinelibrary.wiley.com/doi/full/10.1111/j.1750-3841.2010.01561.x.
- Eng, Qian Yi, et al. “Molecular Understanding of Epigallocatechin Gallate (EGCG) in Cardiovascular and Metabolic Diseases.” Journal of Ethnopharmacology, U.S. National Library of Medicine, 10 Jan. 2018, www.ncbi.nlm.nih.gov/pubmed/28864169.
- Diepvens, Kristel, et al. “Obesity and Thermogenesis Related to the Consumption of Caffeine, Ephedrine, Capsaicin, and Green Tea.” American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 1 Jan. 2007, journals.physiology.org/doi/full/10.1152/ajpregu.00832.2005?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed.
- Hartley, Louise, et al. “Green and Black Tea for the Primary Prevention of Cardiovascular Disease.” Cochrane Database of Systematic Reviews, 2013, doi:10.1002/14651858.cd009934.pub2.
- Kuriyama, and Shinichi. “Relation between Green Tea Consumption and Cardiovascular Disease as Evidenced by Epidemiological Studies.” OUP Academic, Oxford University Press, 1 Aug. 2008, academic.oup.com/jn/article/138/8/1548S/4750815.
- Miller, P Elliott, et al. “Associations of Coffee, Tea, and Caffeine Intake with Coronary Artery Calcification and Cardiovascular Events.” The American Journal of Medicine, U.S. National Library of Medicine, Feb. 2017, www.ncbi.nlm.nih.gov/pubmed/27640739.
- Kuriyama, Shinichi. “Green Tea Consumption and Mortality Due to Cardiovascular Disease, Cancer, and All Causes in Japan.” JAMA, American Medical Association, 13 Sept. 2006, jamanetwork.com/journals/jama/fullarticle/203337.
- Wang, Hongqiang, et al. “Effects of Catechin Enriched Green Tea on Body Composition.” Wiley Online Library, John Wiley & Sons, Ltd, 6 Sept. 2012, onlinelibrary.wiley.com/doi/full/10.1038/oby.2009.256.
- Pae, Munkyong, and Dayong Wu. “Immunomodulating Effects of Epigallocatechin-3-Gallate from Green Tea: Mechanisms and Applications.” Food & Function, U.S. National Library of Medicine, Sept. 2013, www.ncbi.nlm.nih.gov/pubmed/23835657.
- Simon P., Gomez-Ramirez, et al. “L-Theanine and Caffeine in Combination Affect Human Cognition as Evidenced by Oscillatory Alpha-Band Activity and Attention Task Performance.” OUP Academic, Oxford University Press, 1 Aug. 2008, academic.oup.com/jn/article/138/8/1572S/4750819.
- Weinreb, Orly, et al. “Neurological Mechanisms of Green Tea Polyphenols in Alzheimer’s and Parkinson’s Diseases.” The Journal of Nutritional Biochemistry, U.S. National Library of Medicine, Sept. 2004, www.ncbi.nlm.nih.gov/pubmed/15350981.
- Ogunleye, Adeyemi A, et al. “Green Tea Consumption and Breast Cancer Risk or Recurrence: a Meta-Analysis.” Breast Cancer Research and Treatment, U.S. National Library of Medicine, Jan. 2010, www.ncbi.nlm.nih.gov/pubmed/19437116.
- Chen, Yuetong, et al. “An Inverse Association between Tea Consumption and Colorectal Cancer Risk.” Oncotarget, vol. 8, no. 23, 2017, doi:10.18632/oncotarget.16959.
- Kurahashi, Norie, et al. “Green Tea Consumption and Prostate Cancer Risk in Japanese Men: A Prospective Study.” OUP Academic, Oxford University Press, 29 Sept. 2007, academic.oup.com/aje/article/167/1/71/185454.
- Liu, et al. “Effect of Green Tea on Glucose Control and Insulin Sensitivity: a Meta-Analysis of 17 Randomized Controlled Trials.” OUP Academic, Oxford University Press, 26 June 2013, academic.oup.com/ajcn/article/98/2/340/4577179.
- Iso, Hiroyasu, et al. “The Relationship between Green Tea and Total Caffeine Intake and Risk for Self-Reported Type 2 Diabetes among Japanese Adults.” Annals of Internal Medicine, U.S. National Library of Medicine, 18 Apr. 2006, www.ncbi.nlm.nih.gov/pubmed/16618952.
- Zheng, Xin-Xin, et al. “Green Tea Intake Lowers Fasting Serum Total and LDL Cholesterol in Adults: a Meta-Analysis of 14 Randomized Controlled Trials.” The American Journal of Clinical Nutrition, U.S. National Library of Medicine, Aug. 2011, www.ncbi.nlm.nih.gov/pubmed/21715508.
- Kokubo, Yoshihiro, et al. “The Impact of Green Tea and Coffee Consumption on the Reduced Risk of Stroke Incidence in Japanese Population.” AHA/ASA Journals, 14 Mar. 2013, www.ahajournals.org/doi/full/10.1161/STROKEAHA.111.677500.
- Kuriyama, Shinichi, et al. “Green Tea Consumption and Mortality Due to Cardiovascular Disease, Cancer, and All Causes in Japan: the Ohsaki Study.” JAMA, U.S. National Library of Medicine, 13 Sept. 2006, www.ncbi.nlm.nih.gov/pubmed/16968850.
- Suzuki, Etsuji, et al. “Green Tea Consumption and Mortality among Japanese Elderly People: The Prospective Shizuoka Elderly Cohort.” Annals of Epidemiology, Elsevier, 22 July 2009, www.sciencedirect.com/science/article/abs/pii/S1047279709001653.
- Hsu, Stephen, et al. “Green Tea Polyphenol Induces Caspase 14 in Epidermal Keratinocytes via MAPK Pathways and Reduces Psoriasiform Lesions in the Flaky Skin Mouse Model.” Experimental Dermatology, U.S. National Library of Medicine, Aug. 2007, www.ncbi.nlm.nih.gov/pubmed/17620095.