What was the first thing you did this morning? Did you tumble out of bed, stumble to the kitchen and pour yourself a cup of ambition? If so, you are not alone. As a nation, the UK drinks 95 million cups of coffee every day, so says the British Coffee Association.

Tea is even more popular, with more than 100 million brews glugged on a daily basis. And teachers, it seems, are on the front line of caffeine consumption. A 2014 survey for pressat.co.uk found that teaching is the profession consuming the most coffee - just behind journalists and police officers.

This is probably not surprising to anyone who has sat, bleary-eyed, through an early-morning staff briefing after an evening marking marathon. The idea of a simple beverage that can provide you with the energy boost you need to face your first lesson of the day is certainly appealing.

But how far should teachers be relying on caffeine to get them through their days?

The health messages around coffee, in particular, can be confusing. For example, in 1991, the World Health Organization included coffee in a list of possible carcinogens; in 2016, it was removed because there wasn’t conclusive evidence of a link with cancer.

So, what are the costs and benefits of your cappuccino habit? James Betts, co-director of the Centre for Nutrition, Exercise and Metabolism at the University of Bath, says that the power of caffeine should certainly not be underestimated.

The impact of caffeine on teaching

“Caffeine is a potent pharmacological agent. It is absorbed by pretty much everything in your body incredibly quickly and its effects are so profound you can immediately feel that kick on the central nervous system to make you feel alert,” he explains.

However, not everyone will react to that kick in the same way, says registered dietitian Lisa Simon, from Plant Based Health Professionals UK. The extent to which we can tolerate caffeine really varies from individual to individual.

“Some people are super-sensitive while others seem to be able to drink coffee all day long, including at night, and it doesn’t keep them awake. It depends on how you metabolise caffeine,” says Simon.

Much of the research on caffeine centres around coffee and the evidence suggests that, in moderation, it’s a beverage that brings some health benefits.

“Coffee, along with dark chocolate, contains plant compounds called polyphenols, which have an antioxidant effect,” Simon explains.

Antioxidants can “help prevent or minimise damage” caused to the body by stressors that come from the environment (pollution, for example); lifestyle choices, such as smoking; or a diet that’s heavy on sugar, fat and processed foods.

Indeed, a meta-analysis conducted by Robin Poole and colleagues and published in the BMJ in 2017 found that coffee consumption was “more often associated with benefit than harm” for a range of health outcomes. They found that consumption was associated with a lower risk of several specific cancers and neurological, metabolic and liver conditions.

Another 2017 study, by Marc Gunter and colleagues, looked at coffee drinking and mortality in 10 different European countries, and found similar results. The researchers concluded that “coffee drinking was associated with reduced risk of death from various causes” .

There’s good evidence to suggest that drinking coffee is generally not detrimental to our health, then - quite the opposite.

Yet the majority of coffee-drinking teachers are not rushing to the shared jar of granules in the corner of the staffroom each morning for the potential benefits to their livers; they’re doing it for the energy boost that caffeine can provide.

Most of us are familiar with the idea of dosing up on coffee to help us when we’ve had a rough night’s sleep, but does this really work?

Up to a point, according to a study conducted earlier this year at Michigan State University’s Sleep and Learning Lab. In the study, 276 participants were either kept awake overnight in the lab or sent home to sleep. In the morning, all participants were given a capsule containing either 200mg of caffeine or a placebo. They completed a simple attention task and a more challenging “placekeeping” task, where steps had to be taken in a specific order.

Study author Kimberly Fenn said at the time: “We found that sleep deprivation impaired performance on both types of tasks and that having caffeine helped people successfully achieve the easier task. However, it had little effect on performance on the placekeeping task for most participants.”

So, while caffeine can help us to feel more alert, its effects on our ability to complete higher-level tasks - such as planning that complicated lesson - may, in fact, be rather limited.

And there is another downside on the concentration front, too, according to Simon.

“Caffeine can be quite addictive. So, you might start increasing your caffeine intake over time to get the same effect and then you’re drinking more and more,” she says.

This matters because the amount of caffeine you consume affects all the benefits listed above; have too much of it and those benefits could be wiped out.

“Caffeine is a stimulant. It can increase stress levels and make you jittery and anxious if you have too much,” says Simon.

She recommends avoiding an “excess of caffeine”, which is “more than six cups of coffee a day”, although most experts agree that between three to four cups a day is unlikely to have significant adverse effects.

However, beyond the amount you drink, the timing of your morning coffee may also have health and wellbeing implications, according to research from Betts and his team, published last year in the British Journal of Nutrition.

Their study looked at the impact of caffeine on blood sugar levels after a broken night’s sleep - that yo-yoing between sleep and wakefulness that comes with having small children, stress or feeling uncomfortable.

“We know from previous research that caffeine can have some effects on insulin sensitivity. We thought that if people have had a bad night’s sleep, they’re not just going to get up and eat their breakfast - they’re likely to have caffeine with that in the form of a strong coffee. So, we gave participants a strong coffee before breakfast, which revealed that if you’ve had a bad night’s sleep and then have coffee as the remedy, you have clearly impaired blood glucose control. Blood sugars were increased as a result of having caffeine,” says Betts.

Why is that a bad thing? “Keeping good control of your blood sugar is a symptom of good health. If you have repeated episodes of high glucose, if you’re getting lots of high peaks in blood sugar then failing to bring them back down into the normal range quickly, it can cause inflammation and complications, which ultimately lead to chronic diseases like diabetes-associated cardiovascular disease,” he explains.

One possible way of mitigating this caffeine-related spike in blood sugar is to drink your coffee after breakfast. “We have to be pragmatic,” says Betts. “If you tell people ‘don’t drink coffee’ they’re going to switch off. But a more simple message is: would it be the end of the world if you had your porridge first and then your coffee?”

There are other ways in which we can take a smarter approach to our caffeine consumption, too. For example, Simon advises cutting out caffeine after 2pm to avoid sleep disruption.

It’s also worth remembering here that, despite their healthy image, drinks such as green tea and matcha tea also contain caffeine, so make sure that it isn’t just coffee that you avoid in the afternoons.

If you don’t want to forego your flat white habit entirely but you’re keen to cut down, without missing out on the antioxidant benefits, Simon suggests “switching every other coffee to a decaffeinated version - you’ll still be getting the polyphenols in there”, she says.

Turmeric lattes are also a good bet, she adds, as “turmeric contains curcumin, which is a powerful antioxidant”.

“Once you cut down, you’ll find that your energy levels improve because you’re not having those spikes and drops of energy. You’re not needing to have caffeine to bring you back to maintain a more steady energy level,” says Simon.

In the long run, then, cutting down on caffeine could have a positive impact on your energy levels. But above all, remember that your morning cuppa is ultimately no substitute for a good night’s sleep.

Christina Quaine is a freelance journalist

This article originally appeared in the 29 October 2021 issue under the headline “Tes focus on…caffeine”