Heavy Drinkers: Smaller Brains?

A new study indicates that the brains of people who drink large amounts of alcohol get smaller.

Psychiatrist and substance abuse expert Dr. Robert Millman says that doesn't surprise him in the least.

Millman, who's with New York Presbyterian Hospital / Weill Cornell Medical Center, says it makes complete sense, considering how much of a poison alcohol is. People recovering from alcoholism can take six months to a year to fully regain their cognitive abilities, such as memory and ability to do abstract thinking. So, it follows that alcohol has a physical impact on the brain.

"According to this study of 1,800 people, which is a lot," Millman told co-anchor Hannah Storm on The Early Show Friday, "fourteen drinks a week was classified as a lot of drinking. … When you think about it, 14 drinks a week is not so much for a lot of people."

A drink was classified as a glass of wine, a bottle of beer, or an ounce-and-a-half of vodka.

The researchers discovered that the brains of people who drink a lot were more than 1.5 percent smaller than people who don't drink.

"It's been known for years, or thought for years," Millman remarked, "that, if you drank a lot, your brain shrunk. You would get some sort of atrophy of the brain. But it's never been shown in this kind of a systemic way. And it's never been with this many people. This is actually a remarkable study, showing that the more you drink, the more your brain shrinks, up to about 1.6 percent, which isn't huge, but it's significant."

One observation in the study was that women's brains appeared to shrink more markedly than men's.

Again, that's no surprise to Millman. He notes that men are bigger, and earlier research found that women's bodies contain far less of an enzyme that metabolizes alcohol. Women only have 25 percent as much of it as men. So, alcohol in its most poisonous form is more likely to linger in a woman's body. Also, men have more water in their bodies than women, making men more capable of diluting alcohol.

Women handle alcohol worse than men in numerous ways. Among them: They react more intensely to the alcohol they consume, and are less able to predict the effects of what they're about to drink. So, it follows that the same amount of drinking would affect a woman's brain more than a man's.

The apparent effect on the brain is just more evidence of how poisonous alcohol is, Millman stresses. It hurts all parts of our bodies. It's well-known that alcohol affects the liver. It also can damage the heart and intestinal lining, and aggravate existing illnesses such as diabetes. And that's not to mention its role in accidents and psychological illnesses.

True, Millman continued, in very moderate amounts, alcohol is found to improve cardiac health. But in larger amounts, it is poison.

So how much alcohol might actually be good for you?

"A little," Millman responded to Storm. "One or two drinks a night, but not every night. The big danger is to drink every day without a break, and more than three drinks a day."

This study comes out just four months after another one found that when people stop drinking, their brains appear to grow. That, says Millman, is an interesting observation in that it provides hope of an ability to recover, and an incentive for people now drinking heavily to stop, though it's far from certain that any recovery they enjoy would be complete.

That research, Millman told Storm, showed "that maybe you're not knocking off parts of the brain, that it's just weakening."