It was only when he quit caffeine cold turkey that Pollan fully appreciated the mental and psychological boost his morning cup of coffee had provided: "I just couldn't focus," he says. "I lost confidence. The whole book seemed like a really stupid idea. And loss of confidence is actually listed as one of the symptoms of caffeine withdrawal."
Eventually the withdrawal symptoms subsided. Pollan lasted three months without caffeine — during which time, he says, his quality of sleep improved markedly. But now his research is complete and he's returned to his daily caffeine fix.
"I think the word 'addiction' has a lot of moral baggage attached to it," he says. "As [Johns Hopkins researcher] Roland Griffeth told me, if you have a steady supply of something, you can afford it and it's not interfering with your life, there's nothing wrong with being addicted."
Interview highlights
On his experience of giving up caffeine for three months
The thing that really struck me was that I've never had [attention deficit hyperactivity disorder]. I can focus pretty well. I felt like, oh, this is what ADHD is like. I can't keep stuff out of the peripheries. The peripheral information and sense data keeps rushing in and getting in the way. I felt like I was a horse that had taken its blinders off, and suddenly I could see too many degrees of circumference. So that was a real problem for working. I really had trouble sitting and writing and staying still.
After a few days, this began to lift. I think anyone who delays having their morning cup of coffee knows what I'm talking about, but there was a kind of a sense of a veil or fog that had descended between me and reality. I was just kind of muzzy-headed and that gradually lifted. But I have to say, even weeks later, I felt like there was a little mental hitch between me and reality. I felt as if this wasn't my natural language — speaking in another language, which never goes that well or that smoothly. ... I got over it eventually, and I wrote a big chunk of the piece without the influence of caffeine. ... But it was an interesting three months. I recommend it actually. I think it's a really interesting exercise.
On how going without caffeine improved his sleep
It was amazing. I was sleeping like a teenager again. I would pop off, and just sleep through the night — which I don't do that often. And I had some great sleeps. I guess that was the the big compensating benefit of giving up caffeine. ... Caffeine is the enemy of good sleep. ...
It's a problem in ways we don't perceive, because caffeine undermines the quality — not necessarily the quantity — but the quality of our sleep. And specifically, one very particular kind of sleep, which I'd never heard of before, called "slow wave" or deep sleep. This isn't REM sleep where you're having dreams, or light sleep. This is a really deep place you go for not that long a part of the night, but it's really important to your mental and physical health. It's where these slow waves start radiating from the front of your brain into the back, and they kind of harmonize all the neurons, get them on the same page. It's where you kind of take memories from short-term working memory and put them in their proper place. It's like cleaning up the desktop on your computer at the end of the day.
Matt Walker, the psychologist who wrote Why We Sleep, thinks that this is very important to our health to have sufficient amounts of deep sleep. As we get older, we have less of it naturally. And coffee or tea cuts into that, even if you stop drinking it, say, at noon, because caffeine has a very long half-life and quarter-life. So, for example, the caffeine you ingest at noon — a quarter of it is still circulating in your bloodstream at midnight. It's still around. And this is the subtle and, perhaps, insidious effect it's having on you.
On how caffeine withdrawal works
It's beginning when you wake up. I mean, you haven't had coffee or tea since sometime the day before. ... All those people who tell you, "I'm not civil" [or] "I'm not fit for human conversation until I have a cup of coffee." They're beginning to go through that withdrawal. They're starting to feel a little off — that muzzy-ness is coming in. Maybe they have a headache. Maybe they're a little irritable. And then they have that cup of coffee and the pleasure they're getting from it, I learned, is not simply the lift, the euphoric lift of the drug. It's the suppression of the symptoms of withdrawal. We go through that cycle.
One of the things you learn when you take a caffeine fast, as I did, is that the experience of caffeine is very different to a caffeine virgin or a restored caffeine virgin, as I was, than it is to someone who's addicted. Those people [who are addicted] are getting a little bit of lift, but mostly what they're getting is the relief from these symptoms that are about to come down on them. And that feels pretty good. You're back to baseline. But when you're off for a few months, man, it's something else. It's a very powerful drug experience. And I was not prepared for it at all.
On how caffeine keeps us alert
We have a neurotransmitter called adenosine. ... Over the course of the day, levels of it rise and its job is to gradually make us tired — create what's called sleep pressure. So, eventually, we turn out the lights and go to sleep, [and] there is a receptor that the adenosine fits into. And, as it turns out, caffeine fits into the same receptor — it gets there before the adenosine has a chance to. So it essentially blocks the action of that neurotransmitter — you never get the signal that you're tired.