Neither green tea nor coffee is universally “better” for you. Both are linked to longer lifespan and lower disease risk, but they affect your body in meaningfully different ways. The best choice depends on what you’re optimizing for: steady energy, fat burning, heart health, or gut comfort. Here’s how they actually compare.
Caffeine: A Major Difference in Dose
A standard cup of brewed coffee delivers roughly 90 mg of caffeine. A cup of green tea contains about 38 mg, less than half. That gap shapes almost everything else about how the two drinks feel and what they do inside your body.
If you’re sensitive to caffeine, get jittery easily, or drink your beverages later in the day, green tea gives you a gentler lift. If you need a strong wake-up signal or rely on caffeine for athletic performance, coffee is the more efficient delivery system. The amount of caffeine also drives differences in stress hormones, sleep quality, and digestive effects covered below.
How Each One Affects Your Stress Response
Coffee triggers a cortisol spike of about 50% above baseline, based on a review of 10 studies covering roughly 2,500 people. Tea produces a much milder increase of around 20%. The reason isn’t just lower caffeine. Green tea contains an amino acid called L-theanine that promotes relaxation and partially counteracts the stimulant effect of caffeine.
This is why many people describe the green tea experience as “calm focus” versus the more intense, sometimes anxious buzz from coffee. If you already deal with high stress levels or anxiety, this difference matters. Repeated large cortisol spikes throughout the day can disrupt sleep, increase appetite, and keep your body in a heightened state of alertness it doesn’t need.
Fat Burning and Metabolism
Green tea has a genuine edge here. A study published in the American Journal of Clinical Nutrition found that a green tea extract shifted the body’s fuel use toward burning more fat, measured by a drop in respiratory quotient from 0.88 to 0.85. The key finding: caffeine alone, in amounts matching what was in the green tea, did not produce the same effect. The antioxidant compounds in green tea (catechins) appear to promote fat oxidation on their own, independent of the caffeine boost.
That said, the effect is modest. Green tea won’t replace exercise or compensate for a poor diet. But for people already managing their weight, it provides a small metabolic advantage that coffee doesn’t replicate.
Heart Health and Blood Pressure
This is where the picture gets more nuanced. A large study published in the Journal of the American Heart Association found that green tea was not associated with increased cardiovascular death risk across any blood pressure category. Coffee, on the other hand, doubled the risk of cardiovascular death among people with severe hypertension (grade 2 or 3) who drank two or more cups per day.
For people with normal blood pressure, coffee appears safe at moderate intake. But if you already have high blood pressure, green tea is the clearly safer option. Previous research cited in the same study found that drinking seven or more cups of green tea daily was associated with a 62% reduced risk of death among stroke survivors and a 53% reduction among heart attack survivors, though those are observational findings and can’t prove cause and effect.
Antioxidants: Different Types, Similar Benefits
Both drinks are rich in protective plant compounds, just different ones. Coffee’s primary antioxidant is chlorogenic acid. Green tea’s is a catechin compound called EGCG. Both have demonstrated anticancer and anti-inflammatory properties in lab studies.
One safety note worth knowing: green tea’s EGCG is safe at normal drinking levels (up to about 700 mg per day from brewed tea), but concentrated green tea supplements delivering 800 mg or more of EGCG per day have been linked to liver toxicity. If you stick to drinking brewed tea rather than popping extract capsules, this isn’t a concern.
Digestive Comfort
Coffee is a well-known trigger for acid reflux. It stimulates your stomach to produce more acid, which can rise into the esophagus and cause heartburn. This is partly a caffeine effect and partly due to other compounds in coffee. Green tea can also increase reflux symptoms because it still contains caffeine, but the effect is generally milder given the lower caffeine dose.
If you deal with heartburn, GERD, or a sensitive stomach, switching from coffee to green tea often reduces symptoms without giving up caffeine entirely. People with no digestive issues typically tolerate either one fine.
Bone Health
Research from the UK Biobank and studies in Asian populations have found a positive association between tea drinking and bone mineral density, particularly in postmenopausal women. Coffee shows a more mixed picture. Some epidemiological research links coffee to improved bone density, but a large Swedish cohort study found that long-term coffee consumption was associated with a small reduction in bone mineral density in women (though not with actual fracture risk).
Neither drink is likely to make or break your bone health on its own. But if osteoporosis risk is a concern for you, the evidence tilts slightly in green tea’s favor.
Which One Should You Choose
Green tea is the better fit if you have high blood pressure, acid reflux, anxiety, or sensitivity to caffeine. It offers a unique metabolic benefit for fat burning that coffee can’t match, and it produces a calmer, more sustained energy without the cortisol surge.
Coffee is the better fit if you need a strong cognitive or physical boost, have no cardiovascular risk factors, and tolerate it without digestive issues. At moderate intake (one to three cups a day), it’s associated with health benefits of its own, including lower risk of type 2 diabetes and certain neurodegenerative diseases.
There’s also no rule that says you have to pick one. Many people drink coffee in the morning for the stronger kick and switch to green tea in the afternoon. That approach gives you the antioxidant variety of both, keeps your total caffeine reasonable, and avoids late-day cortisol spikes that could interfere with sleep.