Why do women binge drink when estrogen surges? Study explains

Women may not be able to resist

binge drinking

on days their

estrogen levels

are high, says a new study. The research published in Nature Communications found that women may consume large amounts of alcohol in the first 30 minutes after it’s offered due to an increase in the sex hormone estrogen, as per a preclinical study led by scientists at Weill Cornell Medicine.
Estrogen is a sex hormone that’s required for maintaining sexual and reproductive health. It is normal for estrogen levels to fluctuate. They are likely to rise during ovulation and dip as menopause nears. It also dips during your period.
The study published in Nature Communications delves into the drinking behaviour in females and the impact of hormones on it. The study finds out that circulating estrogen plays a role in increasing binge alcohol consumption in females and contributes to known sex differences in this behavior. The findings could help scientists find ways to tackle alcohol addiction.
Alcohol drinking behavior is less studied in females as the majority of studies done have been around males. However, females too display binge drinking behavior and are more susceptible to the negative effects of alcohol than males.

According to the New England Journal of Medicine, women produce less alcohol dehydrogenase (ADH), the enzyme that breaks down alcohol, leading to slower alcohol metabolism. Additionally, higher body fat and lower body water levels cause women to experience stronger physiological effects from alcohol. The International Journal of Addiction study says women with alcohol struggles tend to start drinking later in life than men, but it takes them much less time to develop alcohol addiction. Women also are more at risk of experiencing liver disease and damage to their hearts and nerves than men.

During the pandemic lockdown, women increased heavy alcohol consumption more than men as per several studies. This pattern could spell disaster for women’s health.

A 2021 study revealed that a specific subpopulation of neurons in the brain’s bed nucleus of the stria terminalis (BNST) was more excitable in female mice compared to males. This increased activity was linked to their binge drinking behavior.
But what causes this neural circuit to be more excitable in females? “Estrogen has a significant influence on many behaviors, especially in females,” the researchers noted. “It makes sense that it would also play a role in modulating drinking.”

How the study was conducted

The researchers in the study monitored the hormone levels throughout estrous cycle of female mice and subsequently served up the alcohol. Researchers found that females tend to drink significantly more on days when their estrogen levels are high compared to days when their estrogen levels are low.
This increased binge drinking behavior was linked to heightened activity in the same neurons within the BNST.
“When a female takes her first sip from the bottle containing alcohol, those neurons go crazy,” senior author Kristen Pleil, an associate professor of pharmacology said. “And if she’s in a high-estrogen state, they go even crazier.”
This enhanced neural activity resulted in the female mice hitting the bottle even harder, specifically within the timeframe of first 30 minutes after alcohol was made available to them.

Pleil and her team discovered that estrogen directly excites neurons in the BNST, triggering binge drinking within minutes. Using chemically modified estrogen that couldn’t enter cells, they found that the hormone binds to surface receptors on neurons, directly influencing cell-to-cell communication and promoting binge drinking.
“We believe this is the first time that anybody has shown that during a normal estrous cycle, endogenous estrogen made by the ovaries can use such a rapid mechanism to control behavior,” Pleil said. That rapid action drives the front-loading of alcohol when estrogen is high.

The team has found out the specific estrogen receptor responsible for this effect, finding it present in the activated BNST neurons as well as in neurons from other brain regions that stimulate them. They are now exploring the signaling mechanisms behind this process and plan to investigate whether the same system influences drinking behavior in males.
“All of the infrastructure is there in males, too: the

estrogen receptors

and the basic circuit organization,” Pleil said. The only difference will be the source of the estrogen, which in males without an ovarian source relies on local conversion of testosterone to estrogen in the brain.
Inhibiting the enzyme that produces estrogen could provide a new way to reduce alcohol consumption during hormone surges. An FDA-approved version of this inhibitor is already used to treat women with estrogen-sensitive cancers.
“Combining this drug with compounds that modulate the downstream effects of the chemicals produced by the BNST neurons could potentially provide a new, targeted approach for treating alcohol use disorder,” Pleil said.