Science confirms it: drinking alcohol makes people want to have unsafe sex.
Drunkenness and unwise choices have always gone hand-in-hand, but scientists in Canada wanted to know which came first — the drinking or the propensity for chancy behavior.
They analyzed the results of 12 experiments in which people were randomly assigned to drink or not to drink and then probed about their willingness to have sex without a condom. The more people drank, the researchers found, the worse their decisions — an increase in blood alcohol level of 0.1 mg/mL led to a 5% increase in the likelihood of unprotected sex. The legal blood alcohol limit in the U.S. is 0.8 mg/mL.
The authors’ larger goal was to figure out how big a role drinking may play in risky sex that leads to HIV infection. Although unsafe sex is a well-known risk factor for HIV, and despite safe-sex campaigns for the prevention of HIV/AIDS, rates of infection haven’t budged in high-income countries over the past decade, the authors noted.
“Drinking has a causal effect on the likelihood to engage in unsafe sex, and thus should be included as a major factor in preventive efforts for HIV,” said principal investigator Juergen Rehm of the Centre for Addiction and Mental Health in Toronto, in a statement. “This result also helps explain why people at risk often show this behavior despite better knowledge: alcohol is influencing their decision processes.”
The study appears in the journal Addiction.