At this point, most of us have heard about the benefits of green tea. The National Center for Complementary and Integrative Health points out that much of the evidence isn't conclusive, though, and more studies are needed. Megan Casper, RDN, a New York City–based dietitian, notes another key caveat: "Many studies of green tea use green tea extract, which can be much stronger than your average at-home brew."
The type of tea you drink and how you prepare it also matters. "Hot tea [may] have more antioxidants since iced tea usually uses [fewer] tea bags and is watered down," says Casper, "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 remove the antioxidants.
Learn more about the possible health benefits of green tea and how this popular drink can complement a healthy diet and lifestyle.
Green Tea Packs a Nutritional Punch
When you choose 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 increase mental focus
- Fluoride, a mineral that strengthens 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).
When deciding on a brand, Natalie Rizzo, RD, of New York City, 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 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 catechins (polyphenols) in green tea may trigger thermogenesis and fat oxidation — the process of burning calories and fat — which may help with weight loss, per one animal study.
“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 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.
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The Benefits of Green Tea Extend to Your Belly
Too much caffeine can give you the jitters and affect your sleep, but the stimulant can also 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 Mayo Clinic, an 8 ounce (oz) cup of caffeinated brewed coffee contains between 95 and 165 milligrams (mg) of caffeine, whereas an 8 oz cup of brewed green tea contains 25–29 mg of caffeine.
Green Tea May Reduce Rheumatoid Arthritis Symptoms
If you’re looking to decrease inflammation, add green tea to your shopping list.
In one study, 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 one review 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 one study, 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 occurs in humans.
Green tea may also be used to treat skin conditions such as eczema and genital warts, per a research article.
Green Tea Can Lower Blood Sugar Levels in People With Type 2 Diabetes
People with type 2 diabetes have high blood sugar (hyperglycemia) caused by a condition called insulin resistance, in which 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 reduce insulin resistance, according to a study in which participants who consumed 150 milliliters (ml) of green or sour tea three times per day for four weeks saw positive results.
Your Alertness and Brain Health May Improve if You Drink 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, according to a systematic review. 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 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.
One review 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.
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 research from 2023. Similar effects may be seen with black tea, too.
If you’re 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 Reduce Anxiety, but More Research Is Needed
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 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.
The Takeaway
Green tea is high in antioxidants and offers potential health benefits. Research has found that it may positively impact weight management and heart and brain health. It can be consumed in different forms, including as a warm beverage.
Reyna Franco, RDN
Medical Reviewer
Reyna Franco, RDN, is a New York City–based dietitian-nutritionist, certified specialist in sports dietetics, and certified personal trainer. She is a diplomate of the American College of Lifestyle Medicine and has a master's degree in nutrition and exercise physiology from Columbia University.
In her private practice, she provides medical nutrition therapy for weight management, sports nutrition, diabetes, cardiac disease, renal disease, gastrointestinal disorders, cancer, food allergies, eating disorders, and childhood nutrition. To serve her diverse patients, she demonstrates cultural sensitivity and knowledge of customary food practices. She applies the tenets of lifestyle medicine to reduce the risk of chronic disease and improve health outcomes for her patients.
Franco is also a corporate wellness consultant who conducts wellness counseling and seminars for organizations of every size. She taught sports nutrition to medical students at the Albert Einstein College of Medicine, taught life cycle nutrition and nutrition counseling to undergraduate students at LaGuardia Community College, and precepts nutrition students and interns. She created the sports nutrition rotation for the New York Distance Dietetic Internship program.
She is the chair of the American College of Lifestyle Medicine's Registered Dietitian-Nutritionist Member Interest Group. She is also the treasurer and secretary of the New York State Academy of Nutrition and Dietetics, having previously served in many other leadership roles for the organization, including as past president, awards committee chair, and grant committee chair, among others. She is active in the local Greater New York Dietetic Association and Long Island Academy of Nutrition and Dietetics, too.
Kristeen Cherney, PhD
Author
With a doctorate in English (rhetoric and composition), Dr. Cherney focuses her academic scholarship on the intersection between disability and literacy. She also holds a Master of Arts in English and a Bachelor of Arts in communication.
Cherney has contributed to the books The Wiley Handbook on Violence in Education: Forms, Factors, and Preventions, Composing in Four Acts: Readings for Writers, and Georgia State University's Guide to First-Year Writing, as well as to scholarly journals like Praxis, the Journal of Teaching Writing, and the Journal of Dracula Studies.
Cherney enjoys running, meditating, hiking, and paddleboarding.