By now, most of us are aware of the caloric dangers of non-diet soft drinks and the increased risk of obesity that drinking them brings. Now a new study has found that the more non-diet soda teens drink, the more prone they are to violence. Teens who drank more than five cans of non-diet, fizzy soft drinks every week were significantly more likely to carry a weapon and act violently toward peers and siblings.

The study looked at 1,878 teens who took part in the Boston Youth Survey, a biennial survey of 9th to 12th graders (14- to 18-year olds). The students were from 22 public schools in Boston.

Soda had the same impact as alcohol on those teens who were heavy consumers of non-diet carbonated soft drinks. It raised the probability of aggressive behavior by 9 to 15 percent.

The teens were asked how many carbonated, non-diet soft drinks they had drunk over the past seven days. Their intake was measured in cans (12 ounces or 355 ml), and the students' responses ranked according to quantity.

Based on these responses, the students were divided into two groups: those who drank up to four cans over the preceding week (the low consumption group); and those drinking five or more cans of soda in the previous week (high consumption). Nearly one in three (30%) respondents fell into the high consumption category.

Then researchers looked at violent behavior, asking if the student subjects had been violent towards their peers, a sibling, or a partner, and if they had carried a gun or knife over the past year.

They also analyzed responses to account for factors likely to influence the results, such as age and gender, alcohol consumption, and average amount of sleep on a school night. They found that those who drank 5 or more cans of soft drinks every week were significantly more likely to have drunk alcohol and smoked at least once in the previous month.

Even when those factors were considered, heavy use of carbonated non-diet soft drinks was significantly associated with carrying a gun or knife, and violence towards peers, family members and partners.

Nearly 43% of those drinking 14 or more cans a soda a week carried a gun or knife, as compared to 23% of those drinking one or no cans a week. Violence toward partners, peers and siblings also rose at a similar rate between the high- and low-consumers.

Soda had the same impact as alcohol on those teens who were heavy consumers of non-diet carbonated soft drinks. It raised the probability of aggressive behavior by 9 to 15 percent.

The results may remind some of what became known as the "Twinkie defense." During the murder trial of Dan White, the San Francisico supervisor convicted of killing San Francisco Mayor George Moscone and gay supervisor, Harvey Milk, it was asserted that White's acts were in part the result of his having switched from a healthy diet to one containing junk food, including the sugary snack cakes. (White was convicted of voluntary manslaughter based on his mental instability.)

The authors, Sara J. Solnick and David Hemenway of The University of Vermont and Harvard School of Public Health respectively, concluded that, "The influence of soft drink consumption on violence appears to be a ‘dose- response’ relationship, with effects visible at low levels of consumption and increasing with greater consumption."

It is important to keep in mind that further study is needed to determine why sugary soda consumption is positively Correlational study with violent behavior. According to the authors, "There may be a direct cause-and-effect-relationship, perhaps due to the sugar or caffeine content of soft drinks, or there may be other factors, unaccounted for in our analyses, that cause both high soft drink consumption and aggression."

The study was published online ahead of print in the journal, Injury Prevention.