Green and black teas share many health-supporting properties — from enhancing alertness to guarding heart and brain health. Both are abundant in antioxidants though they vary in specific compounds. Neither is automatically “better” for health than the other.
Both black and green teas come from the leaves of the Camellia sinensis shrub.
A key distinction is that black tea leaves are rolled and subjected to oxidation (exposed to air), while green tea leaves are kept unoxidized. This chemical change darkens black tea leaves to brown, whereas green tea leaves stay green.

Green and black teas may slightly differ in caffeine levels and antioxidant profiles, but they deliver comparable health advantages.
Benefits both green and black tea share
Despite their differences, green and black tea may offer overlapping health benefits.
May support cardiovascular health
Both varieties are loaded with polyphenols, protective antioxidant compounds. In particular, they contain flavonoids, a subclass of polyphenols.
Their flavonoid concentrations can differ. A 2021 study reported that black tea had a higher total flavonoid level than green tea.
A 2023 review of prior trials on green tea and heart health found that consuming it may meaningfully and positively affect cardiovascular health, and could also improve both diastolic and systolic blood pressure.
Similarly, a 2022 cohort analysis using data from 498,043 adults aged 40–69 in the U.K. (2006–2010) evaluated black tea’s impact.
The investigators observed that consuming two or more cups of black tea daily was modestly linked with a reduced risk of death from all causes, including deaths related to:
- cardiovascular diseases overall
- ischemic heart disease
- stroke
Some evidence for green tea, however, indicates its intake might not lower heart disease risk for everyone.
May enhance cognitive performance
Both green and black tea contain caffeine, a central nervous system stimulant.
Green tea generally has less caffeine than black tea — about 29 milligrams (mg) per 8-fluid-ounce cup, versus roughly 47 mg in the same serving of black tea.
Caffeine may help to:
- improve alertness
- shorten reaction time
- reduce feelings of fatigue
- lower risk of depression and suicide
Both teas also provide the amino acid L-theanine, which is not present in coffee.
L-theanine is believed to stimulate release of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in animal and human studies, producing a state of relaxed alertness.
It also encourages release of dopamine, a neurotransmitter linked to mood elevation.
Green tea tends to have a bit more L-theanine than black tea, though amounts vary greatly between cups.
Green tea: a rich source of the potent antioxidant EGCG
Green tea is notable for its high level of the powerful antioxidant epigallocatechin-3-gallate (EGCG), which accounts for many of its reported health effects.
A brewed cup of green tea typically supplies 200–300 mg of EGCG.
Possible benefits attributed to EGCG in human, animal, and lab studies include:
- anticancer and antitumor activity
- improvements in neurodegenerative conditions such as Parkinson’s and Alzheimer’s
- liver-protective effects
- anti-inflammatory actions
- vasoprotective effects (protection of blood vessels)
Black tea: contains healthful theaflavins
Theaflavins are a class of polyphenols found specifically in black tea. They offer numerous health benefits connected to their antioxidant capacity.
These compounds are produced during oxidation and make up about 3–6% of the total polyphenols in black tea.
Theaflavins can shield lipid cells from free radical damage and may support the body’s own antioxidant systems.
They may also help protect against metabolic syndrome with actions that are:
- antiobesity
- lipid-lowering
- blood sugar–reducing
- uric acid–lowering
- beneficial for gut microbiota

Which tea should you choose?
Although green and black teas differ in their polyphenol makeup and processing, both provide robust antioxidant support. They may exert comparable benefits for heart and brain health.
Some 2017 research suggests green teas could exhibit higher antioxidant capacity than black teas.
While both contain caffeine, black tea typically has more, so it may suit people who want a caffeine lift stronger than most green teas but milder than coffee.
Green tea also offers more L-theanine alongside moderate caffeine.
No single tea is definitively “healthier” — it largely depends on your taste and desired effects. For more on how compounds in tea affect taste and health, consider reading about tannins in tea.
Bottom line
Green and black tea each deliver similar health advantages, particularly for cardiovascular and cognitive health.
Both supply caffeine, antioxidant compounds, and L-theanine, which contributes to a calming effect.
Current evidence doesn’t strongly favor one tea as superior in health; both are valuable additions to a balanced diet depending on your flavor preferences and caffeine tolerance.





















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