Coffee starts the morning. Tea gets us through the afternoon. An energy drink promises another few hours of concentration. Cola quietly adds another dose.

Caffeine has become so embedded in everyday life that giving it up can sound almost eccentric.

“I couldn't function without coffee” is said casually, often with a laugh.

But there is an interesting question hiding inside that statement.

Why should we need a stimulant simply to feel normal?

The answer, for many people, is that we don't.

Caffeine can improve alertness and reduce feelings of fatigue. Coffee and tea can also be pleasurable rituals with an important social dimension. There is no compelling reason for every healthy person to abandon them.

But caffeine is not an essential nutrient. The human body does not require a daily dose of it to function.

And once the initial adjustment is over, living without caffeine may be considerably easier — and more pleasant — than habitual users imagine.

What caffeine actually does

Caffeine does not manufacture energy.

It primarily works by interfering with the action of adenosine, a chemical involved in the body's increasing sense of sleep pressure as the day progresses.

The result is familiar: we feel more awake.

That can be genuinely useful. A morning coffee may improve alertness and concentration. For some people, caffeine can improve aspects of physical performance as well.

But there is an important distinction between feeling less tired and no longer needing rest.

Caffeine can mask some of the sensation of fatigue. It cannot replace sleep.

That distinction is easily forgotten in a society that frequently treats tiredness as an inconvenience to be chemically negotiated.

Then tolerance enters the equation

Regular caffeine consumption can produce tolerance.

Someone who once felt noticeably stimulated by one coffee may eventually regard that same coffee as necessary merely to start the day.

This creates an intriguing cycle.

Consume caffeine regularly enough and the absence of caffeine can itself produce symptoms: headache, tiredness, irritability, reduced alertness and difficulty concentrating.

Have a coffee and those symptoms disappear.

It can therefore feel as though the coffee has transformed an exhausted person into a functioning one.

Sometimes, however, part of what has happened is simpler: caffeine has relieved the effects associated with not having the caffeine to which the body has become accustomed.

That does not make coffee inherently bad.

It does challenge the idea that everyone who says they need caffeine necessarily needs it in the ordinary meaning of the word.

Giving it up can initially feel terrible

This is where simplistic advice to “just stop drinking coffee” falls apart.

People accustomed to substantial amounts of caffeine may feel decidedly worse when they stop.

Headaches are common. So are fatigue, sleepiness, irritability and difficulty concentrating. Symptoms generally resolve, but the experience can be unpleasant enough to convince someone that caffeine was essential after all.

It wasn't necessarily.

The body was adjusting to its absence.

For that reason, someone wishing to reduce caffeine may find gradual reduction more comfortable than suddenly going from several coffees or energy drinks a day to none.

There is no prize for suffering through withdrawal.

Then something interesting can happen

Once caffeine is no longer driving the daily cycle, mornings can become remarkably ordinary.

You wake up.

You become alert.

You start the day.

There is no urgent trip to the coffee machine required before conversation can begin.

For some people, another change is more important: sleep.

Caffeine has a relatively long half-life, and a significant amount can remain in the body hours after consumption. An afternoon coffee therefore isn't necessarily finished with us by bedtime.

Sensitivity varies enormously between individuals, but people struggling with sleep sometimes overlook caffeine because they are drinking it many hours before going to bed.

The paradox is obvious.

We consume caffeine because we are tired.

Caffeine can interfere with sleep.

Poorer sleep makes us tired.

So we consume more caffeine.

Removing or reducing it can interrupt that loop.

Anxiety and the racing body

Caffeine's stimulant effects are not universally pleasant.

At higher doses, or in people particularly sensitive to it, caffeine can contribute to nervousness, restlessness, tremor, palpitations and feelings of anxiety.

One person's pleasant morning lift can be another person's uncomfortable racing heart.

This is one reason sweeping declarations about caffeine are unhelpful.

Human responses differ.

The person happily drinking two coffees before lunch and sleeping soundly that night may have little reason to change anything.

The person consuming coffee throughout the afternoon, sleeping badly, waking exhausted and immediately reaching for another coffee has a different equation to consider.

Coffee isn't the enemy

There is another important distinction.

Caffeine and coffee are not synonymous.

Coffee is a complex drink containing numerous compounds, and observational research has repeatedly found associations between coffee consumption and various health outcomes. Tea likewise contains compounds beyond caffeine.

That means an argument that humans can live perfectly well without caffeine should not be distorted into an argument that coffee is poison.

It isn't.

For most healthy adults, moderate caffeine consumption can fit comfortably within a healthy lifestyle. Australian and international health guidance generally focuses on limiting excessive intake and exercising particular caution during pregnancy and in people who are especially sensitive to caffeine.

The sensible question is not:

Is caffeine good or bad?

It is:

What is caffeine doing for me?

There is also the ritual

For many people, giving up caffeine sounds like giving up coffee.

It doesn't have to.

Decaffeinated coffee retains the experience remarkably well. Herbal teas offer the same pause in the day. Even the ritual of boiling a kettle, sitting down and holding a warm cup can survive perfectly well without a pharmacological stimulant attached to it.

That matters because much of our attachment to coffee is behavioural and social.

Meeting for coffee is rarely really about caffeine.

It is about stopping.

Talking.

Thinking.

Being with another person.

None of those things requires caffeine.

Energy drinks deserve separate consideration

Coffee and tea have been consumed for centuries. Modern energy drinks introduce a somewhat different cultural phenomenon.

They can contain substantial caffeine, are often consumed quickly and may be marketed around performance, endurance, gaming, sport or simply getting through a demanding day.

For young people in particular, caffeine can arrive without the traditional boundaries surrounding coffee — not as one morning cup, but as a cold sweet drink that can be consumed almost anywhere and at almost any time.

That makes awareness of total daily caffeine intake increasingly important.

Coffee at breakfast, another at work, cola at lunch, an energy drink in the afternoon and chocolate later in the evening can produce a cumulative intake that the person consuming it may never have consciously calculated.

Try the experiment

Perhaps the most revealing approach is not to declare war on caffeine at all.

Treat its absence as an experiment.

Reduce consumption gradually. Allow the body time to adjust. Notice sleep. Notice afternoon energy levels. Notice whether mornings eventually become easier without the requirement for an immediate stimulant.

Some people will discover little difference and happily return to their morning coffee.

Others may discover something they did not expect.

They don't actually miss caffeine.

They may miss the taste of coffee.

They may miss the ritual.

They may miss sitting outside a café with a cup in front of them.

All of that can remain.

What disappears is the feeling that the day cannot properly begin without a chemical instruction to wake up.

The Times View

Caffeine is one of the world's most socially accepted psychoactive substances, and for most adults moderate consumption need not be regarded as a problem.

But acceptance has gradually become something more curious: dependence is often treated as normal, amusing and even part of our identity.

Perhaps we should separate enjoyment from necessity.

Have a coffee because you enjoy coffee. Drink tea because you love tea. Appreciate the ritual, the aroma and the conversation surrounding them.

But there is something quietly liberating about discovering that you do not actually require caffeine to be awake, productive or happy.

A cup of coffee can be one of life's pleasures. It becomes a different proposition when we believe we cannot face life without it.