No wonder everyone was so angry about Mayor Michael Bloomberg’s soda ban.

In a study of nearly 1,900 Boston teenagers, Harvard researchers found that “heavy” consumers of sugary soft drinks (five or more cans per week) were significantly more likely to engage in violent behavior with peers and carry weapons.

The strength of the effect was on par with the correlation (well known among researchers) between these behaviors and alcohol and tobacco use; in some cases, the correlation with soda was stronger.

Even within the scientific community, people found these results very surprising, Hemenway reports: “When you think about the causes of violence, soft drinks are not on the map of variables that you tend to look at.”

It ain’t causal, mind you, but the correlation is strong, and has been backed up by further Harvard studies of adolescent populations across the country.

Cue a renewing and recycling of the Twinkie Defense, perhaps?