A UAB study, led by Sylvie Mrug, PhD and published in the Journal of Adolescent Health, has identified soft drink consumption as a likely predictor of aggressive behavior.

Interviews with 5,147 children and their caregivers were conducted from three sites, at child ages 11, 13 and 16. At each time, the children reported on their frequency of consuming soft drinks, aggressive behavior and depressive symptoms.

The study showed that soft drink consumption at ages 11 and 13 predicted more aggressive behavior at the next time point. Aggressive behavior at age 13 also predicted more soft drink consumption at age 16. Soft drink consumption at age 13 predicted fewer depressive symptoms, but depressive symptoms did not predict soft drink consumption. Findings from this study suggest that reducing adolescents' intake of soft drinks may reduce aggressive behavior, but not depressive symptoms.

A number of studies have found that more frequent consumption of soft drinks has been associated with more aggression, other behavior problems such as hyperactivity and oppositional behavior, and depression and suicidal behavior in adolescents from the United States, Norway, Slovakia, Iran and China. Another recent cross-national study found a consistent association between adolescents' high sugar consumption and fighting, bullying and substance use in 24 of the studied 26 countries.

All of these studies have included statistical adjustments for a variety of potential confounders such as child age, gender, BMI, physical activity, diet, substance use and family factors.

Although the results are typically interpreted in terms of soft drinks' contributing to behavioral problems, it is equally likely that mental health problems may be driving the consumption of sugar-sweetened soft drinks, Mrug says. Studies show that some individuals consume more sugary foods in response to negative emotions.