Green tea is a centuries-old beverage enjoying a resurgence today. Some people sip hot or cold green tea because they enjoy the taste and the ritual, while others are attracted to its health benefits. Green tea originates from the leaves of the Camellia sinensis plant.
Unlike black tea, where the leaves are oxidized, green tea is an unoxidized form of tea. The lack of oxidation preserves more of the tea’s antioxidants, compounds that fight free radical stress that damages cells. But antioxidants aren’t the only bioactive ingredient in green tea. A cup of green tea contains more goodness than you might imagine. Here are seven you should know about.
Catechins
Catechins are the antioxidant components of green tea. It’s these compounds that account for most of the anti-inflammatory and antioxidant benefits of green tea. The most potent and best studied catechin in green tea is called epigallocatechin-3-gallate (EGCG), but there are other related catechins in a cup of green tea.
The anti-inflammatory effects even hold when you apply EGCG topically. Some anti-aging skincare products contain EGCG, since inflammation plays a role in skin aging. You can boost the amount of EGCG and other catechins in your cup of tea by steeping it longer so more catechins enter the water.
To get the health benefits of EGCG, you might be tempted to take a green tea supplement, but there have been isolated cases of liver toxicity in people taking green tea extract in supplement form. Why might this happen? Scientists still don’t understand the mechanism, but it is best to avoid concentrated green tea supplements and stick to drinking green tea.
Theanine
If you are stressed, the theanine in green tea is a dose of calm. Theanine increases levels of a calming neurotransmitter in the brain called GABA. When GABA predominates, you feel calmer and more relaxed, but still alert. Despite the caffeine in green tea, it usually doesn’t cause the jitteriness that coffee does. Theanine may explain that difference. To get the most theanine, look for a high-quality Japanese green tea or matcha, the whole leaf form that comes in a ground powder. Matcha also contains more catechins than steeped green tea.
Vitamin C
Most people don’t think of green tea as a source of vitamin C, but it supplies around 8% of the recommended daily intake (RDA) of vitamin C. Since vitamin C is an antioxidant vitamin, the combination of catechins and vitamin C in green tea gives your body an antioxidant boost. You can increase the vitamin C content of green tea even more by adding a squirt of lemon. Additionally, citrus increases the absorption of catechin from green tea. Vitamin C is important for the production of collagen, the component that keeps your joints healthy, your skin firm and youthful.
Caffeine
One reason people drink coffee and tea is to get a boost in caffeine. Green tea has around 25 milligrams of caffeine, less than black tea or coffee. But the caffeine content of green tea varies widely, and with how long you steep the tea. Steeping longer and using water at a higher temperature will increase the caffeine content of a cup of tea. Matcha and tea leaves grown in the shade have higher levels of caffeine. Caffeine makes you feel alert, but too much can make you feel jittery. Green tea balances caffeine with theanine for balance and more relaxed alertness.
Saponins
Saponins are compounds with anti-inflammatory and antifungal properties. Saponins also moderately reduce cholesterol in the body if you consume them regularly. It’s saponins that give some versions of green tea a bitter taste. In mouse studies, saponins led to a drop in triglycerides, blood cholesterol, and reduced deep belly fat called visceral fat. Saponins bind to cholesterol in the digestive tract, so that less is absorbed into the bloodstream.
Chlorophyll
Green tea is also a source of chlorophyll, a pigment that gives plants their green color. The green color of spinach, kale, Swiss chard, and other leafy greens comes from their chlorophyll content. Chlorophyll is a natural deodorizer. Some sources also claim chlorophyll is a natural detoxifier, but there’s not enough evidence to support this claim.
Minerals
Green tea also contains a variety of minerals, including calcium, zinc, magnesium, potassium, copper, and phosphorus. The quantities are modest, but you will get some minerals when you drink a cup of green tea. But make sure you get even more by eating fruits and vegetables. Drinking green tea alone isn’t enough to supply the minerals your body needs for good health.
Do the Bioactive Compounds in Green Tea Translate into Health Benefits?
Green tea has anti-inflammatory properties, and some studies show that it may reduce the risk of cardiovascular disease and some types of cancer, although this area needs more research. The anti-inflammatory compounds in green can also lower blood pressure and improve the function of blood vessels. Other research suggests regular consumption of green tea may lower the risk of type 2 diabetes. Countries who drink a lot of green tea, like Japan, tend to have lower rates of some health problems like cardiovascular disease, type 2 diabetes, and some forms of cancer.
The Bottom Line
You’ll get more catechins from green tea if you make your own at home. Bottled green tea is usually lower in antioxidants and lacks some of the health benefits that home-brewed green tea does. You can buy green tea in silk bags or buy loose-leaf tea to steep at home. Enjoy green tea for its taste, as well as its potential health benefits!
References:
- “Green Tea | NCCIH.” .nccih.nih.gov/health/green-tea.
- “Green tea may lower heart disease risk – Harvard Health.” 01 Dec. 2012, health.harvard.edu/heart-health/green-tea-may-lower-heart-disease-risk.
- Mancini E, Beglinger C, Drewe J, Zanchi D, Lang UE, Borgwardt S. Green tea effects on cognition, mood and human brain function: A systematic review. Phytomedicine. 2017 Oct 15;34:26-37. doi: 10.1016/j.phymed.2017.07.008. Epub 2017 Jul 27. PMID: 28899506.
- “How green tea may prove to be a powerful … – Study Finds.” 13 Feb. 2021, studyfinds.org/green-tea-cancer/.
- HealthyEating.SFGate.com. “What Are the Health Benefits of Saponins?”
- LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; 2012-. Green Tea. [Updated 2020 Nov 20].
- Liver Transplantation. Volume12, Issue12.December 2006. Pages 1892-1895.
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