The Last Word On Nothing

Pam is a former methamphetamine user. On a website for recovering addicts, she posted an entry from a journal she kept at the height of her problem, when she was 19 years old. It’s an engrossing story about how meth — snorted throughout the day, but always at lunch time, in a parking lot — has ravaged her body and personal relationships. Here’s the part I want to talk about:

…I stopped and got a milkshake to try to make myself feel better. The guy in line was flirting with me. I couldn’t smile at him, it was too hard. I answered all of his questions in between grinding my teeth. I sat in my car and forced the disgusting milkshake down my throat. I didn’t feel better until I did another one. I couldn’t get the whole Chick-fil-A biscuit down this morning, but I managed to eat the hash browns. The bad part is, I drove 30 minutes out of my way to go to Chick-fil-A house because I was craving a sweet tea. So, I was late to work… I’m just here killing time until my lunch break. The lunch break I take daily. When I say I’m going to Brittany’s to eat. Then I drive to the Wal-Mart and park.

From television, books and the popular press, I thought I’d already heard about all of the nasty effects of crank: paranoia, stroke, heart problems, acne, loss of appetite, loss of teeth. But what about these carb cravings?

Meth support websites are littered with stories of addicts hankering for sweets but, as far as I can tell, the topic gets little attention in the scientific literature. (I did find one report, conducted by dentists, showing that meth users are more likely to drink soda than are non-users.) A fruit fly study published yesterday provides a possible molecular explanation for the meth-induced sweet tooth.

Most meth research has zeroed in on the brain. The drug spurs excessive release of dopamine, a brain chemical that activates reward pathways and leads to euphoria. Meth use also kills neurons — perhaps, some say, because of toxic chemicals that are released when all of that extra dopamine breaks down. (Because of this neurotoxic effect, meth-exposed mice can be used to model Parkinson’s disease.)

If you’ve ever seen a meth addict, though, you know that the drug wreaks havoc on many other parts of the body. It can damage the heart, lungs, liver, stomach, kidneys, skin, and even sperm. The scientists behind the new study wanted to get a better idea of how meth affects the entire body.

The researchers extracted genetic material from whole frozen flies whose food had been mixed with meth. Then they analyzed the expression patterns of many different genes. (Gene expression is how much RNA or protein is made from a particular gene.)  They found that, compared with normal flies, meth-exposed insects have abnormal expression of a host of genes. These genes are involved in (among other things) iron and calcium regulation, the birth of sperm, muscle contraction and — bingo — carbohydrate metabolism.

Following up on the carb finding, the researchers did a second experiment in which they fed flies both meth and trehalose, a common blood sugar in insects. These flies lived much longer (about 92 hours) compared with flies who ate meth without that extra sugar (50 hours).

This, the researchers say, might give us an explanation for those meth milkshakes. It could be that sugar-eating is a survival mechanism, the body’s attempt to stave off the harmful effects of meth.

But it seems to me that there’s another powerful force involved. The brains of meth addicts are used to running on a super supply of dopamine. If it’s been awhile since they scored, they may resort to a tried-and-true substance for getting the dopamine juices flowing: sugar.

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I gave the young girl in the story the name Pam because I don’t know her real name. On the website, she goes by Babyjk. I also corrected a few of her spelling mistakes, for clarity.

Meth photo by feastoffun, via Flickr