FRIDAY, May 17 (HealthDay News) -- It comes as little surprise that college students sometimes binge drink, but new research shows that college women are more likely to drink unhealthy amounts of alcohol on a weekly basis than are college men.

Much of this difference is probably because the amount of alcohol that's considered safe on a weekly basis is much lower for women than it is for men: seven drinks for women versus 14 for men. But, there's good reason for that difference. Women don't metabolize alcohol in the same way as men, and lesser amounts of alcohol can increase the risk of breast cancer and liver disease in women.

Throughout the study, 15 percent of women exceeded weekly drinking limits compared to 12 percent of men. In addition, men's weekly drinking appeared to go down throughout the year, but not so for women.

"College women adopt a drinking style that will cause toxicity soon. Overall, women drink less than men do, but they don't seem to know how muchless they should be drinking in a week," explained Bettina Hoeppner, lead study author and an assistant professor of psychology at Harvard Medical School.

Hoeppner said the biggest concern is that women may be setting themselves up for long-term health problems, particularly if they're not aware of the safe weekly alcohol limits. She noted that women might think they're fine if they don't binge drink, but it's easy to hit the weekly limit by just having a glass of wine with dinner every night.

The U.S. National Institute on Alcohol Abuse and Alcoholism (NIAAA) defines low-risk drinking as no more than three drinks a day or seven drinks a week for women. For men, those limits are four drinks a day and 14 drinks a week.

The daily limits were set to avoid the physical and thinking problems that can occur from drinking too much in one day. The weekly limits took into account how much alcohol someone would need to consume to raise their risk of chronic health conditions, such as liver disease, sleep disorders, heart disease and some cancers.

Hoeppner's study included 992 college students: 575 females and 417 males. The students provided biweekly reports of their daily drinking habits through a Web-based questionnaire.

Two-thirds of both the men and women exceeded the NIAAA weekly or daily guidelines at least once during the year, according to the study. Slightly more than 51 percent of the women and about 45 percent of the men exceeded weekly drinking limits at least once during the year.

Men were slightly more likely to exceed daily limits than women: 28 percent of men versus 25 percent of women, but the researchers said this difference wasn't statistically significant.

The study findings appear online May 17 and in the upcoming October print issue of Alcoholism: Clinical & Experimental Research.

Dr. Marc Galanter, director of the division of alcoholism and drug abuse at the NYU Langone Medical Center, said he suspects that college women may be trying to drink as much as their male counterparts. "I think these young women are independent souls and are motivated to drink in a manner that's similar to the way that men are drinking," he said. "In terms of what's considered normative, there isn't much difference between men and women now."

But, he cautioned, "Comparable levels of drinking for women have a greater impact in terms of intoxication."

Study author Hoeppner said she didn't think that women were necessarily trying to drink as much as men, just that they might not be as aware of what's considered a safe weekly limit.

"Women need to be reminded that there are weekly limits, and women can exceed those limits quickly. It's important to track the number of drinks you have per week, not just on occasion. And, alcohol prevention information should address the rationale behind weekly limits," Hoeppner suggested.

More information

Learn more about drinking in college from the U.S. National Institute on Alcohol Abuse and Alcoholism.