Teenagers who consume large amounts of soda are more likely to display violent tendencies, according to a study recently conducted by David Hemenway ’66, a professor at the Harvard School of Public Health.

Hemenway, along with his co-author, University of Vermont Economics Professor Sara J. Solnick ’86, found that teens who drank more soft drinks were between nine and fifteen percent more likely to be violent.

The study’s results were published in Injury Prevention, an international peer review journal.

The research was conducted using questionnaires collected from over 1,800 inner-city Boston public school students between the ages of 14 and 18. The majority of the students were African-American, Hispanic, or interracial and came from similar socioeconomic backgrounds.

Among other questions, the students were asked how many non-diet soft drinks they consumed in an average week, whether they carried weapons of any kind, and whether they had been involved in violent acts.

According to Hemenway, the questionnaires covered many different aspects of violence. These included witnessing violence and fearing violence, as well as partaking in violence.

“The more soda the students drank, the more likely the students were to perpetrate violence,” Hemenway said. “It was violence in all areas—against peers, against dates, against siblings—and they were even more likely to carry guns.”

After finding the initial correlational relationship, the researchers set out to control for a number of other factors, including gender, age, ethnicity, body mass index, alcohol use, tobacco use, and sleep. Hemenway said that several of these factors—particularly alcohol and tobacco use—are themselves heavily associated with violence.

Yet after this analysis was conducted, “the relationship [was] still there and ... incredibly strong,” Hemenway said.

According to Solnick, previous studies have suggested that soft drinks have been linked to mood disorders in teenagers.

However, Solnick said that there is not enough data to firmly conclude that soda is a direct cause for an increase in violent tendencies. High soda consumption may simply indicate a poor diet in participants.

“People who drink a lot of soda are missing out on other proper nutrition, and that may lead to aggression and violence,” Solnick said.

Solnick said that she and Hemenway will continue their research by looking at other types of violence, studying the relationship between soft drink consumption and suicidal behavior or self-harm.

“There are so many different factors that contribute to the problem, and we want to untangle all of them,” Solnick said.