Adolescents who drink over five cans of regular fizzy drinks weekly may be more likely to behave aggressively, including carrying a weapon and behaving violently towards peers and siblings, according to a new U.S. study.
The research was based on a biennial survey of 1,878 teenagers aged 14 to 18 at schools in Boston, Mass.
The number of carbonated non-diet soft drinks that each youth had drunk in the past week was measured to create two groups—low consumption (up to four cans), and high consumption (five or more cans).
Just under 30 percent of the participants were found to be in the high consumption group. The researchers found that people in this group were more likely to have drunk alcohol and smoked at least once during the last month.
They were also more likely to carry a gun or knife, and perpetrate violence towards friends and family members.
"There was a significant and strong association between soft drinks and violence," wrote the researchers in their paper. "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."
A dose-response relationship was discovered when these results were split into four consumption categories, despite controlling for factors like drinking alcohol and smoking.
"We thought that when we controlled for cigarettes and tobacco, the effect would disappear. But instead, soft drink consumption was still what mattered," said study co-author Sara Solnick at the University of Vermont, according to CTV News. "Even if kids used tobacco or alcohol, or they did not, it still boosted the risk."
The number of people carrying a weapon rose from just over 23 percent in those who drank one or no cans of soft drink to just under 43 percent in those drinking 14 or more cans. Similarly, violent behavior rose as follows:
- From 15 percent to 27 percent towards a partner;
- From 35 percent to 58 percent towards peers;
- From 25 percent to more than 43 percent towards siblings.
Overall, the researchers found that high consumption of regular fizzy drinks was associated with an increase in aggressive behavior of 9 to 15 percent. This correlation is also seen with alcohol and tobacco.
"We can’t explain why this is happening," Solnick added. "What we have now is just an association. People who are involved in a lot of aggression also drink more soda and we don’t know why."