About Last Night

David Vanderveen figures he should know better. But during a family party last Christmas, Vanderveen, 38, a normally temperate kind of guy, downed several glasses of champagne and Scotch before slurping some Boerenjongens, a Dutch concoction made from whisky and raisins. He spent the next morning on his couch, nursing a heaving stomach, headache and other assorted ills. "I felt like a monkey died in my mouth," says Vanderveen, cofounder of XS Energy Drinks, based in Laguna, Calif. "It wasn't pretty."

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Vanderveen isn't alone in his holiday booze binging. The free flowing hooch at the endless round of parties during the month of December can turn a sipper into a chugger. According to the Distilled Spirits Council of the United States, the $58 billion distilled-spirits industry makes about 25 percent of its profits between Thanksgiving and New Year's. And though there are enough problems with lack of judgment the night of, the saga often continues the morning after with that smorgasbord of pain called the hangover. In medical terms, this full-body assault is called veisalgia.

While hangovers have plagued revelers since early hominids kicked back with some date-palm wine, science still doesn't have a good understanding of how your I-love-everybody yuletide cheer turns into such a biological bah-humbug. There are few studies that examine the hangover and the best way to cure it. But what science theorizes about the hangover may be enough to make any reveler skip the holiday binge.

The misery begins when blood alcohol levels start to fall. Some experts to believe the hangover is a "kind of mini withdrawal," says Robert Swift, professor of psychiatry and human behavior at Brown University and director of research at the Providence Veterans Adminstration Medical Center. Because alcohol is a sedative, your body reacts by releasing various neurochemicals to stimulate the brain. These chemicals cause a rapid pulse, nausea, tremors and light and sound sensitivity--the same symptoms that alcoholics experience when they stop drinking. The worst of the symptoms occur when blood alcohol levels reach zero, also known as "the morning after."

How fast it takes you get to that zero level depends on your liver, which processes nearly all the alcohol you imbibe. And it can metabolize only small amounts of liquor each hour, explains liver specialist Dr. William Carey, professor of medicine at the Cleveland Clinic Lerner College of Medicine. But "every person is going to metabolize alcohol differently," Carey says, with genetics and gender playing a role. On average, the liver metabolizes about one ounce of pure alcohol per hour. That's about 12 ounces of beer, a five-ounce glass of wine or one and a half ounces of liquor.

Which leads to another theory that puts the blame for the hangover on pure physiology. Alcohol is first broken down in the liver into a toxic substance called acetaldehyde. Acetaldehyde is then further broken down into a harmless substance called acetate. At high doses, acetaldehyde causes nausea, vomiting, sweating and other symptoms akin to the hangover. Although there is no acetaldehyde in your system when you have a zero blood-alcohol level, some of the after-effects of the toxin may persist the morning after.