Antioxidants
Matcha contains four catechins: epicatechin, epicatechin-3-gallate, epigallocatechin, and EGCG. Of these, EGCG is the most studied. Research published in Molecules in 2021 found high EGCG concentrations reduce oxidative stress and protect against chronic disease and cellular aging. Studies show matcha provides up to 137 times more EGCG than standard green tea.
Polyphenols in matcha are roughly 10 times higher than in steeped green tea, according to Karolina Jakubczyk, professor at Pomeranian Medical University in Poland. "It is by far the strongest antioxidant I have tested in the lab," she said.
A typical cup of steeped green tea contains about 70mg of catechins. Matcha contains more than 3 times that per serving.
L-theanine and caffeine
A standard serving of matcha made with 1 to 2g of powder contains 35 to 70mg of caffeine. L-theanine, an amino acid concentrated in shade-grown tea leaves, slows caffeine absorption and increases alpha wave activity in the brain, associated with calm alertness.
A 2016 study found beverages containing 25mg of L-theanine significantly reduced anxiety and raised GABA levels in participants under stress. A 2021 randomized placebo-controlled trial in Nutrients followed adults aged 50 to 69 with self-reported cognitive decline across three groups: placebo, caffeine only, and matcha. The matcha group showed improved work capacity and lower stress scores.
"The caffeine is absorbed rapidly and L-theanine is absorbed more slowly, which leads to sustained alertness and focus." — Dr. Sammie Gill, registered dietitian and British Dietetic Association spokesperson.
Brain health
A 2020 study published in Nutrients followed 61 older adults drinking matcha or a placebo daily for two weeks. Female participants showed improvements in episodic memory and overall cognitive functioning. Researchers attributed the results to L-theanine, vitamin K, and lutein.
Matcha contains both vitamin K and lutein, compounds absent from steeped green tea. One cup provides roughly 1mg of lutein and covers approximately 29% of the daily recommended vitamin K intake, according to Japanese food composition data.
Heart health
A 2006 study of 40,530 Japanese adults found those drinking more than 5 cups of green tea per day had a 26% lower risk of death from heart attack or stroke compared to those drinking less than one cup. Matcha shares the same compounds. A 2023 literature review in Frontiers in Nutrition found green tea catechins positively affected lipid profiles, including total cholesterol and triglycerides.
Gut health
A small randomized controlled trial found two weeks of daily matcha consumption increased health-promoting gut microbes and decreased potentially harmful ones. Ron Hills, professor of pharmaceutical sciences at the University of New England, credits this to EGCG catechins, which add healthy bacteria to the gut and may improve metabolism.
Muscle and stress
A 12-week study at Kyoto Prefectural University followed 19 healthy male students doing daily resistance training while consuming two cups of matcha per day. The matcha group showed significant increases in skeletal muscle mass. Subjective fatigue scores were lower, and salivary cortisol, a stress hormone, decreased in the matcha group compared to the placebo group.
Animal research published in Bioscience, Biotechnology, and Biochemistry in 2019 found matcha increased stress tolerance. The same effect was not seen with steeped green tea or low-caffeine matcha, suggesting the caffeine-theanine balance is the active factor.
What to watch
The FDA's general caffeine guideline for healthy adults is 400mg per day. At 60 to 70mg per cup, 1 to 2 cups of matcha stays well within that for most people.
Catechins bind to non-heme iron in the gut, reducing absorption. Anyone with iron-deficiency anemia should drink matcha at least an hour away from iron-rich meals. High doses on an empty stomach can cause nausea.
Quality affects the nutritional profile. Beneficial compounds degrade under heat from industrial milling and through poor storage. Matcha is best consumed within 60 to 90 days of opening. Pesticide and heavy metal contamination is a documented risk in low-quality products. A Certificate of Analysis confirming lead-free status is worth requesting.