Even in Parisian intellectual circles known for heavy drinking, French philosopher and feminist icon Simone de Beauvoir found that a glass of wine had a stronger effect than expected. De Beauvoir even joked that two drinks made him dizzy, long before an existential debate began.
Decades later, science explains why: the female body processes alcohol differently from the male body – usually more quickly and more intensely – and the female brain also responds more strongly to its rewarding effects, even when the amount consumed is the same as men’s.
How alcohol circulates in the body
Alcohol affects the body almost immediately. Before reaching the stomach, the taste buds send a signal to the brain, causing small changes in heart rate, blood flow and brain chemistry to prepare the body.
When you drink alcohol, a small amount is absorbed in the stomach, but most of it moves to the small intestine, where it quickly enters the bloodstream.
Some is metabolized in the stomach and liver by an enzyme called alcohol dehydrogenase (ADH), a process known as first-pass metabolism.
In 1990, researchers gave 20 men and 23 women the same amount of alcohol, adjusted for each individual’s weight. Women drank the same amount as men, but their bodies initially filtered less alcohol, so more alcohol entered the bloodstream, leading to higher average blood alcohol levels.
However, intoxication is not just about how quickly alcohol enters the bloodstream. What happens next in the brain is also different depending on biological sex.
Gender differences
Scientists generally agree that women feel the effects of alcohol earlier on average. Researchers, however, disagree on the reasons for this phenomenon.
German neuropharmacologist and addiction researcher Rainer Spanagel says the dominant factor is “not the enzyme” but rather “body weight.”
Ethanol, according to the researcher, is distributed evenly throughout so-called compartments of the body, including the brain and organs.
Smaller bodies mean smaller compartments. “If a man drinks half a bottle of wine and a woman drinks the same amount, the same amount of ethanol accumulates in a smaller body.”
However, other researchers say weight alone doesn’t fully explain alcohol’s effects on women.
Enzymes, body composition and the brain
Alcohol begins to work as soon as it is consumed and continues to influence the body long after it reaches the brain. “Maybe not so much in terms of weight or height, but body composition shows a bigger difference between the sexes,” says Edward Scotts, of Louisiana State University, US, who studies the neurobiological mechanisms of alcohol use disorders.
Women generally have more body fat and less water than men, which is why alcohol is more concentrated in their blood.
“This all adds up to the difference in ADH,” adds Scotts, who says this enzyme is a crucial initial filter.
“When you drink alcohol, it goes to the stomach first, and there is some ADH in the stomach, but men have more than women,” he says. “So men can metabolize it much faster initially. »
This intrinsic difference helps explain why health guidelines define excessive or harmful alcohol consumption differently for men and women.
Jill Becker, a researcher at the University of Michigan who specializes in sex differences in the brain and behavior, says metabolism and absorption shape intoxication, but daily consumption rarely accounts for this process.
“A glass of wine is the same size for a man or a woman,” says Becker. “I’m not asking how much it weighs to give you less.”
As a result, women often receive a higher dose than their body before the enzymes even begin to work.
Alcohol addiction in women
Once alcohol reaches the brain, women experience a phenomenon called telescoping: a significantly faster progression from consumption to dependence. “They become addicted more quickly and consume larger amounts in less time,” says Becker.
Becker’s observation is supported by research showing that women move more quickly from first use to serious alcohol-related problems and treatment, often after fewer years of drinking and less drinking over their lifetime.
Clinical studies conducted in the 1980s, 1990s, and 2000s consistently found that women experience shorter intervals between drinking milestones, even though they typically start drinking regularly later than men.
Hormones also play a role. Estradiol, the main hormone produced by the ovaries, increases the release of dopamine in the brain. Alcohol indirectly increases dopamine and estradiol amplifies this effect.
“During ovulation, women tend to like substances more,” Becker explained, making them more likely to drink more alcohol. Stress is also a big factor. Women are more likely than men to use alcohol to self-medicate for anxiety or depression.
“Some men self-medicate,” says Becker, “but a higher percentage of women use alcohol and drugs to self-medicate.”
Rethinking equality at the bar
For Becker, science has social implications. “I’m a woman from the 1970s, from the second wave of feminism,” she says.
“(At that time) there was a strong belief that we had the right to drink like men.” This belief was rooted in equality, but biology can make this realization lead to certain complications.
“Women need to be aware that not only will they get drunk more quickly if they drink shots with the man next to them,” says Becker, “but the long-term consequences can also be more devastating.”
The conclusion is not a matter of restriction, but of understanding. Alcohol does not have a greater effect because women drink less.
The impact is greater because women’s bodies, enzymes, hormones and brains respond differently, long before tolerance kicks in.
About The Author
