By Amy Norton
FRIDAY, Aug. 16 (HealthDay News) -- Five-year-olds who drink soda every day may have more behavior problems than kids with soda-free diets, a new study of U.S. children suggests.
After looking at nearly 3,000 urban families, the researchers found that 5-year-olds' scores on a standard measure of aggression tended to climb along with their soft drink intake.
Kindergartners who downed four or more servings per day were particularly aggressive, based on mothers' reports. They were twice as likely as other kids to get into fights or destroy property, and also displayed more attention problems than children who didn't drink soda.
The findings were reported Aug. 16 in the Journal of Pediatrics.
Experts were quick to stress that none of this proves that soda, itself, is at fault.
"This is a correlation. We're not saying soda causes aggression," said lead researcher Shakira Suglia, an assistant professor of epidemiology at Columbia University's Mailman School of Public Health in New York City.
Still, Suglia added, there are already reasons to keep children from drinking sugar-laden and caffeinated sodas. "There's no nutritional benefit of soda for children," she said.
A child psychologist not involved in the research agreed.
It's "impossible to disentangle" the effect of one part of a child's diet on aggression, said Rahil Briggs, director of pediatric behavioral health services at the Children's Hospital at Montefiore in New York City.
"That being said, the American Academy of Pediatrics has repeatedly advocated for the elimination of soft drinks in children's diets [and] schools," Briggs added. "Not limiting their intake, but total elimination." The academy is a leading group of U.S. pediatricians.
That advice, Briggs noted, is based on evidence linking kids' soft drinks to increased risks of obesity, cavities and, possibly, behavior problems.
Some past research has tied high soda intake to aggressive behavior in older kids, Suglia said. The new study extends the findings to young children.
The results are based on more than 2,900 mother-child pairs from 20 U.S. cities, many of whom were from single-mom, lower-income households. At age 5, the mothers reported, 43 percent of the children drank soda at least once a day, with 4 percent downing four or more every day.
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.