Caffeine in Tea and Coffee: The Good, the Bad, and the Buzz

So coffee generally has more caffeine, often double or even triple that of tea.

Caffeine is one of the world’s most widely consumed stimulants, found naturally in over 60 plant species. But for most of us, our daily dose comes from two beloved beverages: tea and coffee. Whether you're reaching for a cup of English Breakfast or a bold espresso, caffeine plays a major role in why these drinks are so energizing — and so addictive.

Let’s unpack what caffeine actually does, compare how it behaves in tea versus coffee, and weigh the benefits and drawbacks of both.

What Caffeine Actually Does

Caffeine is a central nervous system stimulant. Its primary effect is blocking adenosine, a neurotransmitter that promotes sleep and relaxation. By blocking adenosine receptors, caffeine keeps us alert and can temporarily improve concentration, mood, and even physical performance.

Beyond keeping you awake, caffeine can:

• Increase dopamine signaling (the "feel-good" neurotransmitter)

• Enhance physical endurance and reduce perceived effort during workouts

• Improve short-term memory and reaction time

• Temporarily boost metabolism and fat oxidation

But — as with anything — there's a tipping point.

Coffee vs. Tea: The Caffeine Breakdown

Caffeine Content

• Coffee: Typically contains 80–120 mg of caffeine per 8 oz cup

• Black Tea: Around 40–70 mg per 8 oz cup

• Green Tea: Roughly 20–45 mg per 8 oz cup

So coffee generally has more caffeine, often double or even triple that of tea.

Absorption & Effect

Caffeine from coffee hits faster and harder. The energy spike is more immediate, but the crash can be more noticeable too.

Caffeine in tea is buffered by L-theanine, an amino acid that promotes calm and focus. This slows caffeine absorption and produces a gentler, longer-lasting alertness.

The Positives

Caffeine can be good for you, in moderation.

Physical Benefits

• May reduce risk of Parkinson’s and Alzheimer’s

• Can protect liver function

• Linked to lower risk of Type 2 diabetes and stroke

Mental Benefits

• Enhances alertness and cognitive function

• May improve mood and decrease depression risk

• Helps with focus, especially during mentally demanding tasks

Tea-Specific Positives

• Rich in antioxidants like catechins and flavonoids

• L-theanine may reduce stress and anxiety while supporting concentration

• May support immune health and heart function

The Negatives

Too much caffeine — from either source — can backfire.

Physical Side Effects

• Insomnia and disrupted sleep patterns

• Increased heart rate and blood pressure

• Digestive discomfort (especially with coffee)

Mental Side Effects

• Jitters and anxiety

• Dependence and withdrawal (e.g., headaches, irritability)

• Energy crashes after the stimulant wears off

Coffee is more likely to cause these issues due to its higher caffeine content and acidic profile. Tea tends to be easier on the stomach and nervous system, though excessive consumption can still lead to side effects.

Which Is “Worse”?

It depends on the context.

• If you’re sensitive to caffeine, coffee can be harsher — more intense highs, more noticeable crashes.

• If you're looking for a more balanced and sustainable energy boost, tea may be a better option, especially green or white tea.

• Coffee may be more effective for short bursts of productivity or physical performance, but tea can support mental clarity over longer periods.

Neither is inherently bad — it’s about how much you consume, how often, and how your body reacts.

Caffeine is both a helpful tool and a potential troublemaker. Coffee and tea offer different experiences and health benefits, so the best choice depends on your personal tolerance, goals, and lifestyle.

• Want sharp focus and a quick lift? Coffee might be your friend.

• Prefer calm alertness with fewer side effects? Tea is your ally.

At the end of the day, the key is moderation. Listen to your body, stay hydrated, and enjoy your brew — whatever it may be — mindfully.