Why can't women drink as much as men?

When you came to our school you told us that pretty well everything about alcohol was worse for women that it was for men, particularly around BACs for driving, and that we shouldn’t drink as much as a guy does. Why can’t women drink as much alcohol as men?

Thanks for the question. When I stand in front of a group of young women and talk about the impacts of alcohol on women I can see that some of the audience just think that this seems just so unfair! As much as this seems like some sort of male conspiracy the truth is that alcohol does indeed affect women more than men.

Put simply, women aren’t able to drink as much as men because, on average, they are smaller in size and weigh less and they also are unable to absorb and metabolize alcohol as effectively as men. There are three main factors that lead women to be more quickly affected by alcohol and more vulnerable to the effects of alcohol:

Body fat: Women tend to weigh less than men, and their bodies contains less water and more fatty tissue than a man’s (that’s something no young woman wants to hear!). Fat retains alcohol while water dilutes it, and so alcohol remains at higher concentrations for longer periods of time in a woman’s body, exposing her to more alcohol and potentially more damage.

Enzymes: Women have lower levels of two enzymes—alcohol dehydrogenase and aldehyde dehydrogenase—that metabolize alcohol in the stomach and liver. They don’t break down alcohol as well as a man and therefore more alcohol is absorbed into their bloodstream.

Hormones: Changes in hormone levels during the menstrual cycle may also affect how a woman metabolizes alcohol.

We now believe that women who drink also face a greater risk of developing diseases related to alcohol abuse, such as liver disease, heart disease, cancer and particularly breast cancer, than men who drink similar amounts or even more.
Just a quick fact about alcohol and breast cancer that is so important for young women. Each additional standard drink (10g of alcohol) per day raises that a woman drinks increases the relative risk of developing breast cancer over a lifetime by about 10%. This means that a woman’s overall lifetime risk of breast cancer is almost 9 in 100 if she drinks no alcohol. Two drinks per day increases the risk to just over 10 in 100, while six drinks a day ups her risk to about 13 in 100. It’s not about not drinking at all, it’s just don’t drink a lot ….
Of course, we need to remember that everyone is different and there are always going to be exceptions to the rule, but on average, women achieve higher concentrations of alcohol in the blood and become more impaired than men after drinking the same of alcohol. You just have to be a little more careful with alcohol than young men of your age.

First published: May 2015