Neither tea nor coffee is categorically healthier than the other. Both beverages deliver protective plant compounds, both are linked to lower risks of several chronic diseases, and both come with trade-offs depending on how much you drink and what health concerns matter most to you. The real answer depends on your body, your habits, and what you’re optimizing for.
Antioxidant Power: Tea Has the Edge
Tea and coffee contain different families of protective plant compounds, and they don’t overlap much. Coffee is rich in phenolic acids and coumarins. Tea, especially green tea, delivers a broader arsenal: catechins, epicatechin, epigallocatechin gallate (EGCG), quercetin, rutin, and gallic acid, among others. In lab comparisons of standard servings, green tea consistently shows the highest antioxidant potential of the three most-studied beverages (coffee, tea, and red wine). Black tea falls somewhere between green tea and coffee.
That said, antioxidant activity in a test tube doesn’t always translate directly to benefits in your body. What matters more is what these compounds do over years of regular consumption, which is where the disease-specific research comes in.
Heart Health: Similar Benefits, One Key Difference
For most people, moderate coffee drinking has no meaningful effect on cardiovascular death risk. That holds true whether your blood pressure is normal, slightly elevated, or in the mild hypertension range. But there’s one important exception: people with severe hypertension (systolic blood pressure at or above 160) who drink two or more cups of coffee per day face roughly double the risk of dying from cardiovascular disease compared to non-drinkers. A study published in the Journal of the American Heart Association found that hazard ratio was 2.05 for heavy coffee drinkers in this group.
Green tea showed no increased cardiovascular risk at any blood pressure level. Even at five to six cups per day, green tea consumption wasn’t associated with higher cardiovascular mortality. There were hints of a protective effect at moderate intake levels, though the statistical significance faded after adjusting for other lifestyle factors. If you have high blood pressure, tea is the safer daily choice for your heart.
Blood Sugar and Diabetes Risk
This is one area where coffee pulls ahead. A meta-analysis of 30 studies found that each additional daily cup of coffee was associated with a 6% lower risk of developing type 2 diabetes, with the benefit remaining linear up to eight cups per day. Tea also helps, but the effect is smaller: a two-cup-per-day increase in tea intake was linked to a 4.6% reduction in diabetes risk. Both beverages appear protective, but cup for cup, coffee offers a stronger benefit for blood sugar regulation.
Caffeine, Energy, and Stress Hormones
An 8-ounce cup of brewed coffee contains about 96 mg of caffeine. The same size cup of black tea has roughly 48 mg, and green tea about 29 mg. The FDA considers up to 400 mg of caffeine per day safe for most adults, which translates to about four cups of coffee or eight cups of black tea.
The caffeine gap matters beyond just alertness. Coffee triggers a cortisol spike of roughly 50% above baseline, according to a comparative review covering about 2,500 subjects. Tea raises cortisol by only about 20%. Part of this difference comes from the lower caffeine dose, but tea also contains an amino acid called L-theanine that promotes calm focus. L-theanine essentially takes the jittery edge off the caffeine, which is why tea drinkers often describe their energy as smoother and more sustained compared to the sharper (and sometimes anxious) buzz from coffee.
If you’re sensitive to caffeine, prone to anxiety, or find that coffee makes you feel wired and then crashed, tea gives you a gentler ride.
Digestive Comfort and Acid Reflux
Both coffee and tea can relax the valve between your esophagus and stomach, which allows acid to flow upward and cause heartburn. Caffeine is one trigger, but it’s not the only one. Coffee contains other compounds that stimulate acid production, and certain herbal teas (especially peppermint and spearmint varieties) can aggravate reflux through entirely different mechanisms.
A 2019 study in women found that drinking coffee, tea, or soda was associated with increased reflux risk, while substituting water reduced it. Interestingly, a separate 2019 study in men found no association between coffee or tea and reflux symptoms. The effect seems to vary by individual. If heartburn is a regular problem for you, cold brew coffee (lower in both caffeine and acidity) or lighter teas may be worth experimenting with. But the most reliable fix is simply drinking either beverage between meals rather than during them.
Iron Absorption: Both Beverages Interfere
This is a genuine downside shared by tea and coffee, and it’s more significant than most people realize. The polyphenols in both drinks bind to non-heme iron (the type found in plant foods, eggs, and fortified grains) and prevent your body from absorbing it. Drinking tea with a meal can reduce iron absorption by about 64%. Coffee with a meal cuts absorption by 39% to 90%, depending on the food.
The severity depends on the polyphenol concentration. Beverages containing 100 to 400 mg of polyphenols per serving can inhibit iron absorption by 60% to 90%. Since tea generally contains more total polyphenols per cup than coffee, it may interfere slightly more with iron uptake. If you’re at risk for iron deficiency (common in menstruating women, vegetarians, and people with digestive conditions), the simple fix is to wait at least an hour after eating before having your tea or coffee.
Bone Health: Both Are Protective
Older advice often warned that caffeine leaches calcium from bones, but large-scale evidence tells a different story. A 2025 meta-analysis of 14 studies covering more than 562,000 people found that both coffee and tea drinkers had lower rates of osteoporosis than non-drinkers. Coffee drinkers had a 21% lower risk, and tea drinkers had a 25% lower risk. For both beverages, drinking more frequently (at least one cup of coffee per day, or tea at least four times per week) strengthened the protective effect.
The likely explanation is that the anti-inflammatory and antioxidant compounds in both beverages support bone maintenance over time, and this benefit outweighs any minor calcium losses from caffeine.
Which One Should You Choose?
Tea has clear advantages if you have high blood pressure, are sensitive to caffeine, experience anxiety, or want maximum antioxidant variety with minimal stress hormone activation. Coffee is the stronger choice if your priority is diabetes prevention, you need a more potent energy boost, or you simply tolerate caffeine well. Both protect your bones, both contain compounds that fight chronic disease, and both can disrupt iron absorption if you drink them with meals.
The healthiest option is whichever one you’ll drink consistently, in moderate amounts, without loading it with sugar. Three to four cups of coffee or up to six cups of tea per day falls within the range where benefits appear in most research, without crossing into territory where side effects become common. Many people drink both, using tea for calmer moments and coffee when they need a stronger lift, and the evidence suggests that’s a perfectly reasonable strategy.