MONTREAL, Quebec — Why do some people drink more than others? The answers can range from drinking history, to gender, age, and weight. However, researchers from Concordia University argue that a protein that regulates your sleep may also influence your alcohol consumption.

The new study found the Bmal1 gene is involved in alcohol drinking behavior. However, whether it causes you to drink more or less depends on your gender.

Gene promotes drinking in women but not men

The researchers studied how the Bmal1 gene affected drinking in mice — a verified model in monitoring alcohol consumption and its effects on the brain. Genetic manipulation in one group of mice removed the Bmal1 gene from a brain area known as the striatum. The striatum plays a major role in decision-making and reward.

The team selectively took the Bmal1 gene from the striatum, but not anywhere else, to avoid disrupting the circadian rhythm. Since sleep deprivation has a connection to cognitive problems that may affect decision-making, the team left Bmal1 genes untouched to avoid disrupting the process.

Results show that male mice with the deleted gene drank more than the control group (a separate group of mice with their striatal Bmal1 gene left intact). Interestingly, female mice with the deleted gene showed the opposite effect. Female mice with the deleted Bmal1 gene drank less than female mice who had it.

The findings suggest the Bmal1 gene promotes risky behavior in females while serving as a protective gene for males to drink less.

Evidence for sex-specific treatments for alcohol addiction

The study further adds to the growing research on the sex differences in alcohol consumption.

“So far, the limited biological and pharmacological treatments for alcohol dependence don’t distinguish between males and females, even though there are major differences in alcohol drinking behavior and addiction between the sexes,” says Shimon Amir, a professor of psychology and Distinguished University Research Professor, in a university release. “By discovering sexually dimorphic mechanisms, addiction treatment specialists could ultimately use this knowledge to develop sex-based treatment.”

The gene may explain sex-based differences in drinking behavior as women tend to experience more negative side-effects despite drinking less than men. Understanding why men and women drink differently could help create specialized treatments for people with alcohol addiction.

“It seems that striatal Bmal1 plays a causal role in the control of alcohol consumption and makes an important contribution to sex differences in alcohol intake,” Dr. Amir explains.

The study is published in the journal Communications Biology.