The antioxidants in green tea contain a bounty of possible perks.
Green tea is arguably one of the most famous superfoods out there, but how much do you know about what’s in your cup?
Green tea is made from the leaves of the Camellia sinesis plant, just like all other nonherbal teas. Unlike black and oolong (wulong) teas, though, green tea is less processed, as it’s made using steam-dry methods. The delicate processing techniques are thought to be among the reasons why green tea is so rich in nutrients and antioxidants — all of which may lead to a range of health benefits. In fact, according to the National Center for Complementary and Integrative Health (NCCIH), green tea has been used in Chinese and Japanese medicine practices for centuries.
While you’ve probably heard a lot of chatter about the benefits of green tea, the NCCIH points out that much of the evidence isn’t conclusive, and more studies are needed. New York City–based Megan Casper, RDN, owner of Megan Casper Nutrition, notes another key caveat: “Many studies of green tea use green tea extract, which can be much stronger than your average at-home brew.”
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The potential health benefits of green tea can also vary based on the brand you choose, as well as the way you make it, says Casper. “Hot tea [may] have more antioxidants, since iced tea usually uses [fewer] tea bags and is watered down,” she says, but “tea that is cold-brewed over the course of a few hours has similar amounts of antioxidants as hot tea.” Decaffeinated brands of green tea may also not pack as many benefits because processing can take away the antioxidants.
Newer to the scene and also being talked up for its potential benefits is matcha green tea. Matcha is made from ground whole green tea leaves mixed with freshly boiled water. Casper says this preparation boosts this green tea’s antioxidant content, as well as its caffeine content.
Learn more about the possible health benefits of green tea and how this popular drink can help complement a healthy diet and lifestyle.
Green Tea Packs a Nutritional Punch
In choosing green tea, you can feel good about what’s in your cup. Here’s a look at what’s inside:
- Caffeine, a type of alkaloid, which can have stimulating effects on the nervous system
- Amino acids, such as L-theanine, which may help increase mental focus
- Fluoride, a mineral that helps strengthen tooth enamel
Unlike other types of tea, green tea contains high levels of compounds called catechins. The most notable catechin is epigallocatechin-3-gallate (EGCG).
In terms of choosing a healthy green tea, New York City–based Natalie Rizzo, RD, offers a pro tip: “If you want the real thing, make sure the package says 100 percent green tea or opt for pure green tea leaves.”
Green Tea Can Be Part of a Healthy Weight Loss Diet
The NCCIH notes there isn’t sufficient evidence to prove that drinking green tea will lead to weight loss in people who are overweight or obese. But research involving green tea extract shows it may help.
Namely, the caffeine in green tea may help suppress appetite and speed calorie burning through a process called thermogenesis, suggests one such study. Just know that most of the research out there on green tea is on this more highly concentrated extract; it doesn’t involve the tea bag steeping in your cup, notes an article published in May 2014 in the Canadian Pharmacists Journal.
“If you are thinking of adding green tea to your diet to help with weight loss, don’t expect this to work if you are eating a high-calorie diet,” Rizzo says. “Although it does have fat-burning qualities, [green tea] will not burn enough fat to make up for a bad diet.” On top of that, according to the Mayo Clinic, weight loss efforts via green tea may be inhibited if you drink premade tea with added sweeteners.
Your best bet? Do what’s been proven to work — follow a healthy, balanced diet and exercise regularly to lose weight. Adding green tea to your diet may help, but don’t expect it to be a silver bullet.
The Benefits of Green Tea Extend to Your Belly
Drinking too much caffeine can give you the jitters and affect your sleep, but the stimulant can also help keep you regular. If you’re sensitive to the volume of caffeine in coffee, try green tea instead. It, too, has caffeine but less than coffee. According to the Mayo Clinic, 8 oz of caffeinated brewed coffee contains between 95 and 165 mg of caffeine, whereas 8 oz of brewed green tea contains between 25 and 29 mg of caffeine.
Green Tea May Help Reduce Rheumatoid Arthritis Symptoms
If you’re looking to decrease inflammation, add green tea to your shopping list.
In a study published in The Journal of Nutrition, rats given green tea extract in drinking water that were then induced with the autoimmune disease rheumatoid arthritis (RA) developed less severe symptoms than rats with RA that drank plain water. More studies are needed in humans, but the researchers note that green tea extract may be helpful when used along with conventional RA treatment.
Research in a review published in 2011 in Arthritis Research & Therapy suggests a similar anti-inflammatory benefit in mice with osteoarthritis, but it’s too soon to tell whether the same effects would be seen in humans.
Green Tea May Help Repair Damaged Skin and Protect Against Skin Cancer
In a preliminary study published in February 2010 in Cancer Prevention Research, mice exposed to green tea polyphenols in drinking water showed better skin cell repair after UV ray damage, though it’s not yet clear if this same effect would be observed in humans.
Green tea may also help treat skin conditions such as eczema and genital warts, per an article published in August 2015 in the Journal of the German Society of Dermatology.
Green Tea Could Help Lower Blood Sugar Levels in People With Type 2 Diabetes
People with type 2 diabetes have high blood sugar (hyperglycemia) due to a condition called insulin resistance, where the cells, muscles, and liver cannot effectively absorb glucose to energize the body. Poorly managed diabetes can increase the risk of complications such as heart disease, neuropathy (nerve damage), amputations, and eye problems, according to the American Diabetes Association.
But when part of a healthy type 2 diabetes diet, green tea may help reduce insulin resistance, according to a study published in September 2014 in the Iranian Journal of Medical Sciences. In the study, participants who consumed 150 milliliters of green or sour tea three times per day for four weeks saw positive results.
Your Alertness and Brain Health May Improve by Drinking Green Tea
One of the most popular features of green tea, according to the NCCIH, is mental alertness. This short-term effect is linked to green tea’s caffeine content. Caffeine itself is a stimulant to the central nervous system, which can cause issues when consumed in large amounts. But the low caffeine content in green tea is just enough to wake you up without causing the anxiety and jitters associated with higher-caffeine products, such as coffee.
Green Tea May Help Protect Against Certain Types of Cancer
Cancer happens when free radicals attack healthy cells in the body, but antioxidant-rich foods and beverages like green tea are thought to help prevent this process, according to the National Cancer Institute. Particularly, the EGCG content appears to offer protection.
A review published in February 2018 in Molecules and Cells cites research showing that green tea extract may help delay the onset and prevent the recurrence of certain types of cancer. Nonetheless, much of the research on the connection between cancer prevention or treatment and green tea involves mice or cell cultures, not humans, and green tea extract, not green tea itself.
Drinking Green (and Black) Tea May Have a Protective Effect on the Heart
Along with green tea's cholesterol-lowering properties, the NCCIH notes that the tea may also lower high blood pressure. In turn, this can lead to better heart health, according to the National Heart, Lung, and Blood Institute. Similar effects may be seen with black tea, too.
If you’re currently taking blood pressure medications, such as beta-blockers, drink green tea in moderation. Large amounts of green tea, especially in supplemental form, may interact with these types of medications, according to the NCCIH.
Green Tea May Help Reduce Anxiety, but More Research Is Needed
Having a cup of green tea may help reduce the symptoms of anxiety-related disorders such as generalized anxiety, obsessive-compulsive disorder, and social anxiety disorder. A review published in October 2017 in Phytomedicine cites research that suggests caffeine and the amino acid L-theanine work together to lower anxiety and influence other brain functions, including memory and attention.