You crave it. I crave it. We all crave it. I'm talking chocolate, a food that's in a category by itself. (You crave butterscotch? Then find yourself another web page -- just kidding...).
But what's so special about chocolate? Why do lovers send a chocolate heart for Valentine's Day, instead of, say vanilla cookies or strings of licorice?
It seems that chocolate, like coffee and tea, has an unusual capacity to interact with brain chemistry. For example, Adam Drewnowski of the University of Michigan found that chemically blocking receptors for opiate chemicals produced by the brain decreased the consumption of high-fat chocolates by compulsive, or "binge," eaters by more than half. (The same "opioid" chemical only slightly reduced consumption of women with normal eating patterns.)
Drewnowski, who directs the Human Nutrition Program in Ann Arbor, says, "Our research indicates that opioids are most implicated in the craving for high-sugar, high-fat foods -- chocolate, in particular." Although the suspicion focused on chocolate, the experiment could not prove that the sugar and fat consumed during the test were not causing the response.
As Drewnowski interprets it, chocolate (or sugar or fat) normally triggers the production of opioids, and that when the molecules that recognize opioids are blocked by the test treatment, the craving seems to decline greatly. Most peculiarly, they dropped most sharply in women who have a binge-eating problem. That implicated the receptors -- somehow -- in the causation of their problem.
What's the latest on choco-chemistry?
Chocolate also seems to interfere with another internal chemical signal, if research by Danielle Piomelli is to be believed. Piomelli, a researcher into the chemical effects of marijuana at the Neurosciences Institute in San Diego, has found that chocolate slows the destruction of chemicals that activate marijuana's receptor in the brain.
If he's right, that means that chocolate could preserve a marijuana high. But even more interesting is how chocolate seems to interfere with a pleasant brain chemical your brain can make without a hint of illegal drugs.
I have a feeling...
we need to back up and do some explaining. Major explaining.
About three years ago, scientists announced the surprising news that brain cells have a receptor (defined) for THC, the active ingredient in marijuana. The receptor is part of a signaling network, kind of like the modem on your computer, except it only carries one simple signal: When THC binds to the receptor, Piomelli explains, "We feel high."
The obvious question, he says, was this: "Why should the brain have a receptor for THC?" Were our ancestors on the African savanna smoking something strange? Was that habit helpful enough to enter our genes?
Nice theory, but apparently all bunk. It turns out that the brain produces a chemical that also binds to the receptor that produces effects similar to those of THC, Piomelli explains. "Everything feels better, your perception of time changes -- five minutes can feel like an hour. It's a pain killer in experimental animals." The natural chemical is called anandamide, and Piomelli says it's a "reasonable speculation" that it may play a role in feelings of euphoria.
So what's the bad news?
That's the good part. The bad part is that anandamide, like other neurotransmitters (defined), is broken down soon after it's produced. (But look at the silver lining -- who could stomach a legion of classmates or coworkers incessantly crooning "Oh what a beautiful morning"?)
At any rate, Piomelli's recent experiments indicate that two chemicals in chocolate inhibit the natural breakdown of anandamide. In other words, chocolate could preserve a natural high brought on by whatever caused the release of anandamide in the first place. Here's more on this research.
And while Piomelli says his interest is basic research, the implications for drug development are obvious. "In principle, the idea of interfering with the brain's own substances, as opposed to giving something from outside, may be superior." A disease like depression, he speculates, could be caused by too-quick breakdown of euphoria-causing natural chemicals like anandamide, and thus conceivably could be treated by slowing that breakdown with a drug.
But don't hold your breath -- even if it works, it's probably a decade in the future. Want to take action right now? Then find out who's in the love-sick Why Files team.
