Kindergartners' Soda Intake Linked to Aggression in Study
Nearly half of urban 5-year-olds consume soft drinks every day, their mothers say
Overall, the children's scores on an aggression scale rose in tandem with their soda intake, Suglia's team found. Those scores were based on moms' responses to a standard questionnaire, asking how often their child got into physical fights, destroyed property or otherwise acted out.
"We tried to account for other things that could affect both a child's soda intake and aggressive behavior," Suglia said.
That included mothers' education levels, any reports of domestic abuse and how often kids watched TV or ate sweets. In the end, high soda intake -- four or more a day -- was still linked to a higher risk of aggressive behavior.
The researchers could not account for everything that might explain the link, however. "There's still a possibility that something else is driving this," Suglia said.
It's also not clear how drinking soda would directly affect young children's behavior. Suglia said that in theory, caffeine or sugar might play a role -- though scientific studies have doubted the common notion that sugar makes kids hyper or aggressive.
"One of the limitations of our study is that we don't know what types of soda kids were drinking," Suglia said. "We don't know if they were regular or diet, or caffeine-free."
The beverage industry dismissed the findings.
"It is a leap to suggest that drinking soda causes these or any other behavioral issue. The science does not support that conclusion," the American Beverage Association said in a statement. "The authors themselves note that their study 'is not able to identify the nature of the association between soft drinks and problem behaviors.' Importantly, our member companies do not promote or market the consumption of soft drinks to children in the age group examined in this study."
However, Suglia and Briggs both said parents would do well to ban sugary drinks for kids.
Water is a calorie-free way to hydrate, and milk gives kids needed nutrients, such as protein, calcium and vitamin D. Even fruit juice, Suglia noted, should be avoided if it has added sugar.
"Whether or not research reveals that this link between soda and aggression holds true, there are plenty of well-documented negative effects of soda consumption in childhood," Briggs said.
"Why take chances?" she added.