Take a few good friends, add a swank rooftop patio or late-night loft party, and mix liberally with free-flowing cocktails—it’s a recipe for summer fun familiar to us all. And for a growing number of young women in Canada, drinking a lot—just on occasion—seems like a harmless way to let loose.

On most days, Julia,* 26, sticks to the odd glass of wine with dinner. But in a social gathering, it’s not unusual for her to knock back five or six cocktails. As for the possible long-term impact on her body, she’s untroubled. “I have heard that drinking excessively for a short period of time does damage your health,” she admits, “but I guess I know I’m not going to be drinking this way for long.”

Heavy drinking isn’t just a habit of addicts. In fact, many of us do it. In a recent Statistics Canada survey, almost 30 percent of women aged 18–24 admitted to drinking heavily—defined as at least five drinks in a single occasion, at least 12 times a year. That’s more than enough to count as “binge drinking”. But despite how common it is to go on a bender, health experts say the effects can be serious and last way longer than the morning after, especially for young women.

“Men have more of a stomach enzyme that metabolizes alcohol more quickly. Also, women have a different fat-to-water ratio in their bodies. Men have more water to fat, and for women, it’s the reverse,” explains Scott Walters, an expert on alcohol use and associate professor of behavioral sciences at the University of Texas School of Public Health. “Alcohol is a water-soluble molecule—it will go anywhere there is water. In men, it has more places to spread out. But in women, the alcohol tends to cluster around the brain and vital organs, so it has the effect of hitting them harder.”

As for the lasting impact of drinking too much too often, you don’t have to be a rehab-ready alcoholic to develop problems. “Alcohol, even a pattern of periodic binging, can lead to a whole bunch of health issues, including gastrointestinal and stomach problems,” explains Dr. Robert Strang, chief public health officer of the department of health promotion and protection in Nova Scotia. “Most concerning is that it can increase your risk for heart disease and cancer.”

But what about all the headlines and hype over red wine’s heart-healthy side? “None of that benefit is going to be seen in people who drink a lot all at once,” cautions Walters. While the current research suggests that light or moderate drinking (about one glass of vino a day for women) may help ward off cardiovascular disease, going overboard can do more harm than good.

Thankfully, you don’t have to swear off liquor altogether to stay healthy—just be smart about how you indulge. Think of it like your favourite diet-busting dessert: as a treat, not an all-you-can-eat.

*Name has been changed

Binge Drinking has been edited for FLARE.com; the complete story “Happy Hour” appears in the May issue of FLARE magazine.