Caffeine has been a boon for civilization, Michael Pollan says. But it has come at a cost.

Pollan, the author of "The Omnivore's Dilemma," "The Botany of Desire," "In Defense of Food" and "How to Change Your Mind" - in which he has explored our complicated relationship with food, plants, drugs and many other things we take for granted - has turned his imposing analytical skills to caffeine, the most popular mind-altering chemical on the planet.

"For most of us, to be caffeinated to one degree or another has simply become baseline human consciousness," Pollan writes, well, reads in "Caffeine." "Something like 90% of humans ingest caffeine regularly, making it the most widely used psychoactive drug in the world and the only one we routinely give to children, commonly in the form of soda. It's so pervasive that it's easy to overlook the fact that to be caffeinated is not baseline consciousness but, in fact, is an altered state."

After others suggested the idea, Pollan decided to get off caffeine, cold turkey, to better understand the stimulant's effects on human consciousness. Last year, he abstained from coffee and tea for three months. As he notes in "Caffeine," the experiment nearly killed his enthusiasm for the book. "How can you possibly expect to write anything when you can't concentrate?" Pollan writes about his withdrawal symptoms, a state so intense that it's officially classified as a mental disorder by the American Psychiatric Association.

When Pollan ended his caffeine fast, he promised himself to drink coffee and tea only on Saturdays. Our interview was on a Monday. So what happened?

His Saturday-only policy was proceeding as planned, Pollan says, but then he went to Scandinavia on a book tour in December, when the days are shorter than the attention span of a tween on Twitter. "It was really dark," he says. "It got dark at 2:46 in the afternoon in Stockholm. I remember this. So people are like caffeinated till then, and then they switch over to alcohol, and that's basically how they survive. And I was jet-lagged on top of it, so I started having some caffeine then, and it did get me through that whole experience."

"And now I've lapsed," he adds. These days, he has a half-caff every morning.

Pollan's fall from the wagon is more testimony to the addictive nature of caffeine, a drug that the author argues helped advance civilization while, simultaneously, disrupting our sleep. The introduction of coffee and tea to Europe in the mid-17th century - at the time, alcohol was the drink that fueled and befogged workers - freed "people from the natural rhythms of the body and the sun, thus making possible whole new kinds of work and, arguably, new kinds of thought, too," Pollan writes.

Caffeine would transform the world around us in ways large and small, magnificent and horrific. It would stimulate and focus the mind in a way that would influence the workplace, politics, social relations and "arguably even the rhythms of English prose," Pollan writes. But the cultivation of, and trade in, coffee and tea plants (and the sugar used in both) would also enslave countless people and lead to the East India Company opening an opium trade with China. The drug trade was good for British coffers, but it crippled a great empire.

Once business executives discovered caffeine could improve worker production, coffee became capitalism's silent co-conspirator. Pollan delves into a Fair Labor Standards Act case from the 1950s in which a company, Los Wigman Weavers, made 15-minute coffee breaks mandatory, but refused to pay workers for the breaks. The courts ruled against Wigman, ushering in a law that requires employers to pay workers for short breaks.

Historically, Pollan says, drugs that favor business have fared better under U.S. law than those that don't, though the increasing legalization of marijuana counters that trend.

"I think there is a kind of a bias against drugs that interfere with the smooth working of the economic machine," the author says. "As soon as you get into jobs that involve machines or numbers, alcohol is a challenge. And we did try to ban alcohol, without success. I just think it's too deeply rooted in everyday life to take it on. But in general, you find that the drugs that increase productivity are the ones that are most supported in our society."

With "Caffeine," though, Pollan wanted to separate what's good for civilization (and business) from what's good for humans as a species. He spent considerable time with sleep researchers, most of whom don't touch caffeine because of what it does to the body and the quality of one's shut-eye. Coffee, in particular, has become the solution to the problem that coffee has created, Pollan notes in the book.

"There is no free lunch," Pollan says, laughing at the memory of his struggle without caffeine. "You know, these drugs give us something, and they take something, too. I think, on balance, the advantages exceed the disadvantages. I'm drinking coffee, and it's not just because I'm enslaved to it. I get a lot from it. I get a lot of pleasure, and I'm convinced it helps me with my writing. Getting off it certainly hurt my writing."

Pollan says he started drinking coffee at age 10, more than 50 years ago, mostly as a way to bond with his father, who worked in New York City and would not return home to suburban Long Island until late at night. "So my time with him was in the morning when he was getting ready to go to work. I'd get up early so I could hang out with him, and I started drinking coffee because he drank coffee."

In other words, until Pollan gave up caffeine last year, he had rarely, if ever, known an adult consciousness that was not altered by the drug. Perhaps not surprisingly, he prefers the clarity of mind that caffeine provides. Or what his wife, the painter Judith Belzer, calls the morning "cup of optimism."

Although he prefers the caffeinated life, Pollan is not sure where he stands on whether coffee and tea have been good for humans in general. And even if he were clear, he probably wouldn't tell us, he says.

"Caffeine makes us work harder. Is that good for us or not? What is good for a species?" Pollan says. "The kind of person caffeine made us, someone more likely to be striving and ambitious and highly productive, does that necessarily make us happier?"

"The benefits are clear on the civilization ledger," he adds. "On the species ledger, it really depends if you see civilization as a plus or minus for the species. It does a lot for us, but it also has an enormous cost."