An illustration of a pill container pouring out coffee beans into a jittery hand.

The surprising science behind your coffee addiction

In his book This Is Your Mind on Plants, author Michael Pollan explores our relationships to naturally occurring psychoactive substances – including caffeine. But are we enjoying coffee, or is coffee enjoying us?

The first step is admitting you have a problem

It was a Saturday just over a month ago that I stumbled, with some nervous amusement, upon a passage in Michael Pollan’s new paperback This Is Your Mind on Plants: Opium–Caffeine–Mescaline while sipping my morning coffee.

Some plants, Pollan wrote, have evolved to attract pollinators by "offering them a small shot of caffeine" in their nectar, to "sharpen the memories of bees, making them more faithful, efficient, and hard-working." In a series of studies, he wrote, entomologists found that "bees will remember and return more reliably to flowers that offer them caffeinated nectar". The flowers, in other words, were shrewdly exploiting the unknowing insects.

I looked down at what German naturalist Alexander von Humboldt might call my ‘cup of sunshine’. Over lockdown, particularly, my morning ritual of making coffee had become so important to me that I often went to bed excited to go through its lovely, meticulous stages the next day: scooping the beans; pushing down the cafetiere plunger; taking that first, deeply satisfying sip. Now, all of a sudden, I was left wondering: was my daily coffee routine a lovely, wilful choice, or was I just a bee flying slavishly back to a caffeinated flower?

So, I did what any hand-wringing potential addict might do: I went cold turkey.

Turning to the good book

'Was my daily coffee routine a lovely, wilful choice, or was I just a bee flying slavishly back to a caffeinated flower?'

In This Is Your Mind on Plants, Pollan combines the two approaches, untangling our fraught histories with the three naturally occurring psychoactive substances in the book's title. But it was Pollan’s exploration of caffeine and coffee – a cup of which I currently had snugly nestled into my hand – that ensnared my attention most. In that chapter, for the sake of his book, Pollan takes on the personal experiment of quitting caffeine, urged by experts who suggested that he “really couldn’t understand the role of caffeine in [his] life – its invisible yet pervasive power – without getting off it and then, presumably, getting back on.” The idea, he writes, was that “you can’t possibly describe the vehicle you’re driving without first stopping, getting out, and taking a good look at the thing from the outside.”

So, taking Pollan’s lead, I exited my gorgeous, mocha-coloured vehicle – on whose peppy, caffeinated wheels I’d rolled relatively painlessly through a global pandemic – and immediately felt the slow, gritty crunch of my lumbering footsteps on gravel.

Three weeks on foot

The first day of my caffeine abstention, a Wednesday, was novel at least – I could chat excitedly to my colleagues and laugh about my experiment – but the next day I felt grey and, in a half-word I jotted down in order to compare notes with Pollan's, “blinky”. It was as though a fog had descended on my mental faculties. My writing ideas felt stupid and half-baked. By Friday, my third day of abstention – and by far my worst, perplexingly – I found myself irritable and inarticulate, stumbling over words.

I already wanted to give up.

The following two weeks were a blurry slog. I woke up only to joylessly trudge past the kitchen and my beloved beans to my ‘home office’ (a laptop, a kitchen chair, a kitchen table), where I spent the days straining to focus: I felt discombobulated during meetings; my productivity slowed. My girlfriend noticed a dispositional shift (but didn’t tell me until after the experiment: “You never tell a cranky person they’re being cranky,” she smiled).

Getting to that third Wednesday was going to be gruelling.

Calling for help

If I’m totally honest, I spent much of my abstention wishing I could speak to Pollan; in the throes of decaffeination, I wanted to know how he’d done it. As it stood I had arranged, prior to my experiment, to compare notes with him after it was all over, via Zoom.

My first question: What exactly have I been missing so badly?

“The dose of optimism could be the dopamine release that caffeine gives us,” Pollan explains from his home in Berkeley, “but there could still be aspects of it we don’t fully understand yet.”

Part of coffee’s allure, he surmises, is that it intensifies what cognitive psychologists call ‘spotlight consciousness’, which facilitates focused, linear thinking and reasoning; the result is a feeling of confidence, which Pollan argues is related to focus.

'Part of coffee’s allure is what psychologists call ‘spotlight consciousness’ resulting in a feeling of confidence'

“When you wake up, you’re not focused; you have this swirl of things vying for your attention. Coffee narrows it: there is this sense of possibility that I think is a little like cocaine. You feel strong, like you can do what you have to do.”

More alarmingly, though, is that my lovely morning ritual was not just about that dopamine release and its attendant optimism, confidence, and focus: “You were looking forward to the pleasure of caffeine,” Pollan explains, “but you were also looking forward to stemming the withdrawal from the caffeine.” Or, to put it a more devastating way: those warm, wishful thoughts I had about coffee before bed were actually nascent feelings of withdrawal.

The caffeine cycle

“Here’s what’s uniquely insidious about caffeine”, writes Pollan in This Is Your Mind on Plants: “the drug is not only a leading cause of our sleep deprivation; it is also the principal tool we rely on to remedy the problem. Most of the caffeine consumed today is being used to compensate for the lousy sleep that caffeine causes.”

Here’s how that works: Throughout the day, our bodies produce adenosine, a psychoactive compound with a depressive and hypnotic effect on the brain designed to suppress brain activity; by the evening, as the adenosine binds to receptors in our central nervous system, we become less alert and, eventually, feel the urge to sleep. Coincidentally, caffeine molecules fit perfectly into those same receptors; when we drink coffee, the caffeine binds there first, blocking adenosine from fulfilling its function and keeping us alert.

'Those warm, wishful thoughts I had about coffee before bed were actually nascent feelings of withdrawal'

And it stays there. According to Matthew Walker, author of Why We Sleep: The New Science of Sleep and Dreams, caffeine’s lifespan in the body is such that for most coffee drinkers, 25 percent of the caffeine you enjoy at 10 a.m. is still circulating in the brain at 10 p.m. By the next morning, the built-up adenosine that your body has continued to create is flooding your brain, making you more tired than you would have been without coffee. No wonder my morning coffee felt so good; it was actively stopping me from feeling bad.

For Pollan, day one of his coffee abstention was the hardest, which made sense; why, I asked him, was mine the third? Pollan thinks I was running on fumes.

“People metabolise caffeine at very different rates. It does linger for a long time, and you don’t need a lot of it to stem the withdrawal symptoms; it may be that your liver hadn’t finished doing its job of finishing metabolizing the caffeine you had on your last day.”

Those entomologists discovered another interesting fact about the caffeinated bees: “They kept returning to the caffeinated flowers long after they’d been depleted of nectar.” My hunch had been right: I was a hapless, exploited bee – or, to borrow Pollan’s phrase, “a credulous animal duped by a plant’s clever neurochemistry into acting against its interests.”

Back on the bean

In the end, I went back to coffee on a Monday, two days before I was supposed to. With my liver cleared of caffeine and my adenosine landing properly – and, forgive me, with the work week looming – I was ready to feel the full effects of that gorgeous cuppa. Pollan laughs when I admit this; he, too, quit his experiment early.

For most coffee drinkers, 25 percent of the caffeine you enjoy at 10 a.m. is still circulating in the brain at 10 p.m.

As I scooped the grounds that morning, even the smell felt invigorating, but it was with the first sip that I could feel caffeine’s warm embrace: My heart rate went up slightly; I felt confident and across my work, like all of the day’s tasks were happily within my grasp; I sang ‘Bohemian Rhapsody’, replacing the bit where Freddie Mercury sings “Mamaaaaaaaaa” with ‘java’.

But Pollan put me at ease: though he technically agrees I’m an addict – “I think when you start organising your life around something, it’s verging on addiction” – he says I’m not alone in my relationship to caffeine.

“Coffee had a very small corner of the world before we became addicted to it,” he explains, “and now it’s got universal popularity. You are – we all are – working for these plants, when we use our money to get them to move around the world, summon them to us. It’s all redounding to the benefit of the plant.”

“It was very important for me to include caffeine in this book," he continues, "because people don’t think of it as a drug. But all the same issues apply: it can be a blessing and a curse. There are people who drink seven, eight, nine cups of coffee a day, and are jittery and unpleasant because of it; in the DSM of mental disorders, there’s caffeine use disorder. But it can be a harmless addiction, too; we moralise addiction, whether we should or not.

For my part, I’m more aware of caffeine’s nature, and like Pollan – who, even after writing his book, is back riding the java jalopy with me – I’ve decided to kerb my coffee intake by 11 a.m., in order to have less caffeine bouncing around my system by bedtime. At the end of our interview, I ask Pollan if he had any other epiphanies from his time off coffee.

“My big takeaway is a renewed sense of gratitude for this astonishing plant, which for its own purposes produces this alkaloid that just so happens to unlock this key to our consciousness. We’re learning things about plants now that we just didn’t know: the way that trees communicate underground, all this kind of stuff. I find it astonishing; my respect for plants and their ingenuity just grows and grows.”

Michael Pollan's This Is Your Mind on Plants is out now in paperback.

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