It will come as no surprise that drinking lots of alcohol often goes hand-in-hand with bad decision making. But up until now, scientists had yet to come up with a direct cause and effect relationship regarding alcohol and unprotected sex.
In the January issue of the journal Addiction, a new study reports that researchers in Canada conducted 12 experiments to test the theory. The results–yes, rather obvious–confirmed that drinking alcohol affects decision-making, and the more alcohol one drinks, the more impaired the decision making. As the results show, for every 0.1mg/mL increase in blood alcohol level, study participants were 5 percent more likely to engage in unsafe sex.
While the findings may not seem overly newsworthy, they do confirm the direct connection between alcohol and sexually transmitted diseases. The study’s conclusion states that ”alcohol use is an independent risk factor for intentions to engage in unprotected sex, and as risky sex intentions have been shown to be linked to actual risk behavior, the role of alcohol consumption in the transmission of HIV and other STDs may be of public health importance.”
“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.”

