Is caffeine good or bad for your health? - Health

Jun 25, 2026

We spill the tea on the good, the bad and the jittery.

Working in an open-plan office, it’s hard not to overhear things. Who’s having a bad day. Who’s on the keto diet. Again. Who left their charger at home. So we really weren’t eavesdropping or anything (honest) when we recently overheard that someone a few desk-rows over had decided to quit all caffeine. Not just coffee – everything. Tea. Matcha. Even (brace yourselves) Diet Coke.

Once we stopped reeling from the shock – how do they, like, function as a human being? – it made us curious, and a little worried. Is caffeine actually something ‘bad’ that we should all be giving up? And in that case, was life even worth living? Determined to get to the bottom of it all, I ordered myself an extra-strong extra-large long black double ristretto and knuckled down to do some research.

Credit: Supplied

Is caffeine bad for you?

Caffeine is not ‘bad’ for you in the same way that smoking is ‘bad’ for you, although both can be addictive in their own way. However, caffeine can cause a variety of health issues, especially if you drink way too much of it:

Anxiety and palpitations: consuming too much caffeine can cause or worsen feelings of agitation, ‘the jitters’, anxiety or panic. It can also cause benign heart palpitations, especially in people with caffeine sensitivity, or with underlying heart conditions.
Sleep disruption: caffeine has an average half-life of anywhere from 1.5 to 9.5 hours, which means a significant amount of it can stay in your system into the night if you drink it in the afternoon. Caffeine disrupts sleep by blocking adenosine, the brain’s natural sleep-inducing chemical, making it harder for you to fall asleep and stay asleep.
Digestive issues: caffeine increases gastric acid production and speeds up the contractions in your digestive tract, which can trigger heartburn or an upset stomach.
Dependence and withdrawal: if you’re really dependent on caffeine, missing a dose can cause headaches, irritability and lethargy.

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Is caffeine good for you?

Beyond bringing joy to your everyday, caffeine has been shown to offer a variety of health benefits:

Energy and focus: while blocking adenosine in the brain can keep you up at night, doing the same during the day can help to reduce fatigue and improve focus, short-term memory and reaction times.
Improved mood: caffeine enhances dopamine and influences serotonin pathways in the brain. Regular intake has been linked to a lower risk of depression.
Metabolic and physical performance: caffeine stimulates the nervous system, releasing adrenaline, which breaks down stored body fat and improves endurance during workouts.
Long-term brain benefits: long-term regular coffee and/or tea intake has been linked to a significantly lower risk of neurodegenerative diseases like Alzheimer’s and Parkinson’s.
Other benefits: regular caffeine consumption (particularly coffee) has been linked to a reduced risk of liver disease, stroke and heart disease, and some cancers. It’s also been associated with healthy ageing.

An important point to remember is that everyone processes caffeine differently. Some people metabolise caffeine quickly, and these people are more likely to enjoy the positive benefits. Those who metabolise caffeine slowly are more likely to see the negative side-effects.

How many cups of coffee a day is safe?

According to Food Standards Australia New Zealand, the US Food and Drug Administration and the European Food Safety Authority, 400mg of caffeine per day (roughly 4 cups of brewed coffee) is perfectly safe for the vast majority of healthy adults.