Alcohol intake linked to unsafe sex

By Dr. Ananya Mandal, MDDec 14 2011

It is known that unprotected sexual intercourse is the most common cause of HIV infection and finding ways to prevent unsafe sex is a major goal of public health efforts to prevent HIV/AIDS. It has not been clear whether unsafe sex associated with alcohol use actually led to HIV infection, or whether certain personality traits, such as sensation-seeking or risky behavior, led to both alcohol use and unsafe sex.

In a new study led by Jurgen Rehm, director of social and epidemiological research at the Centre for Addiction and Mental Health in Ontario, Canada, the researchers conducted 12 experiments that tested this cause-and-effect relationship. They concluded that alcohol affects decision-making and that this effect increases with the amount of alcohol consumed. The more alcohol the participants drank, the more willing they were to engage in unsafe sex, the study authors said. For each 0.1 milligrams per milliliter increase in blood alcohol level, there was a 5 percent increase in a participant's likelihood of having unsafe sex. The study is published in the January issue of the journal Addiction.

Rehm commented in a journal news release, “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… This result also helps explain why people at risk often show this behavior despite better knowledge: Alcohol is influencing their decision processes.”

Because the participants reported their own likeliness of having sex without a condom, there is the potential for bias, or underreporting regarding participants' willingness to have unprotected sex. The researchers noted that not all studies that have examined this link have been published, and after they accounted for this, the increased likelihood of having sex after drinking may be only 3 percent.

Despite limitations, the general health message of this research remains the same, and it highlights that alcohol can influence people’s decisions about whether to use a condom. Condoms are the most effective way to prevent the spread of sexually transmitted infections, and as a spokesperson for the Terrence Higgins Trust suggests, “if you know you will be drinking it is practical to make sure you carry a condom with you.”