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Martina M. Cartwright
Martina M. Cartwright Ph.D., R.D.

Do Soft Drinks Really Make Kids More Aggressive?

Media pundits quick to blame sugary sodas for bad behavior. What's the truth?

Yesterday, news headlines were ablaze with the latest nutrition study suggesting that soft drink consumption “causes,” or is associated with, violent and aggressive behavior in children. Television pundits and media were quick to generate inaccurate headlines and blame the sugar and caffeine found in soda for the violent behavior. However, a closer look at the original publication reveal a flawed study that did not evaluate the type of soda consumed by the children. (e.g. sugar vs. sugar free; caffeinated vs. decaffeinated). Yet headlines would have one to believe otherwise, with sensational statements like: "sugary sodas are making our kids violent." So what's the scientific truth? The study failed to show that the oft-cited caffeine and sugar found in soft drinks cause violent behavior. Here’s why:

The Study Data: The study, which was published in the August issue of the Journal of Pediatrics, examined data collected on 5 year olds enrolled in the Fragile Families and Child Wellbeing (FFCW) study. Of the 4898 families participating in the FFCW study, the J Peds study ( examined 60 month follow up “in-home assessments” from nearly 3000 mother-child pairs. These assessments were not specific to soda consumption and behavior. In fact, the assessment inquiries covered a number of topics. Because the data collected for the J Peds study were not intended to look specifically at the association between soda consumption and behavior, it’s tough to make conclusions about this inferred association. Further, the moms responses relied on recollection. Studies have demonstrated that recollection of past diet and behaviors are unreliable.

The Assessment: Mothers were asked to report their child’s behaviors using a Child Behavior Checklist. The trouble is, the checklist questions ask the mother to answer “not true, somewhat or sometimes true or very true-often true” to a series of statements “based on their child’s behavior during the previous 2 months.” ( ) The checklist has been validated as a method to assess aggressive behavior, however, if one is trying to correlate behavior with soda consumption, it is difficult to do so using this tool because the behavior assessment questions cover a 2-month period and the child may not be drinking soda everyday. Moreover, the mom may not accurately recall behavior or soda consumption. Therefore, there is no way to definitively say, at least from this study, that soft drinks cause aggressive behavior.

The Beverages: To assess beverage consumption, the moms were asked, “on a typical day, how many servings of soda does your child drink?” Possible answers were none, 1,2,3,4,and 5 or more sodas in a typical day. The study does make a correlation between number of servings and higher likelihood of “aggressive” behavior….but…what is a serving?

To truly state that there is an association between soda and behavior, the obvious questions that need to be considered are:

• What is a serving? Is junior running around with a 12-ounce can or a 48 -ounce super sized soda? Serving size was not considered in the study. The amount makes a difference especially if one is trying to correlate the quantity with the behavior.

• Did the child drink regular, sugar sweetened soda? Diet soda? Caffeinated soda? No caffeine? The study didn’t consider or record the type of soda. If one is trying to correlate behavior with soft drink-derived sugar or caffeine, it is important to know the type of soda consumed.

• Did the term soda include “energy drinks” or other carbonated beverages? The study didn’t consider this either but in the title the term “soft drink” is used. Which is it? For some people “soda” and “soft drink” do not mean the same thing.

Other Behaviors: The study did look at other sugary drinks, candy and juice consumption and when controlled for these factors, soda was still believed to impact behavior but….How many of these children had a history of ADD or other behavioral issues? The study didn’t assess these other possible behavioral issues.

The study did examine television viewing time, and other factors like the mother’s history of depression, intimate partner violence and paternal incarceration. When these factors were controlled, soda consumption appeared to be linked with behavior…..but…

Television time has an impact on behavior but so does programming. There was no information regarding the types of programs the child watched…were the programs they watched violent?

Aggressive behavior was twice as likely to be displayed by those children who consumed 4 or more sodas a day….but…because there were only 110 children who drank more than 4 sodas a day, its difficult to draw conclusions about the relationship between soda drinking and behavior. Nevertheless, this is an interesting observation…if one is to make the leap to say that aggressive behaviors are triggered by soda intake, what is it about the soda that makes the child more aggressive? Is it the soda itself? An ingredient in soda? The authors admit that, “We were not able to characterize the nature of the associations between soda consumption and the problem behaviors.”

What’s compelling about this study is the 43% of 5 year olds consuming “one serving of soda a day” and the 4% who consume more than 4 servings a day. Again, we don’t know the serving size, but these results beg the question, “why are so many 5 year olds drinking so everyday?” TV “experts” were quick to blame soft drink makers for marketing sodas to kids and making sodas readily available to youngsters, but consider:

Where do the tots get the money to raid the vending machine or to reach the soda dispenser at the convenience store? How does a 5 year old get the heavy 2-liter bottle out of the fridge and pour a cold one? Does junior have the strength to open a pop top can? Most likely the answers to all of these questions is the parent(s) provided the child with the soda. And if someone is giving their 5 year old a serving of soda a day, one has to question the overall nutritional status of the child, how this affects behavior and the degree of parental supervision. Parenting practices significantly impact diet and behaviors of young children. Under supervised young children are more likely to have poor dietary habits and aggressive behavioral issues.

So what are we to conclude from this study? There may very well be a correlation between certain dietary practices and behaviors in children and this study suggests that perhaps soda or soft drinks may trigger negative behavior. The body of scientific evidence does suggest, to a degree, that high caffeine consumption can influence negative behaviors in children, but we don’t know from this study if the aggressive tots were consuming caffeinated soft drinks, and if so, how much. Similarly, the authors and the scientific literature suggest that sugar consumption is not definitively linked to child behaviors. In this study, high fruit juice was linked to less aggressive behavior, but what kind of fruit juice? Not all juices are high in sugar. Also, high candy/sweets were associated with higher aggressive behaviors. What kind of candy, how much? What about the child’s overall diet? What about parental supervision? How many of the children in the study have been diagnosed ADD or other behavioral issue?

Although there are many questions left unanswered by this study to definitively say that soda triggers aggressive behavior in children, most of us would agree that soft drinks should not be a staple in any young child’s diet but rather, reserved as an occasional treat in very small portions. Banning sodas altogether or making them a “forbidden food” won’t curb poor dietary habits. Well-designed studies and observations show that food deprivation enhances cravings and reduces self-regulation. (,

Nutrition education based on science, not sensationalism or deprivation, ignites self-regulation that empowers parents, families and children to make mindful dietary choices that endure. The real challenge is how can we, as nutrition professionals and healthcare providers, better educate parents and families on prudent inclusion of sweet foods into their child’s diet.

About the Author
Martina M. Cartwright

Martina M. Cartwright, Ph.D., R.D., is an adjunct professor of Nutritional Sciences at the University of Arizona and an independent biomedical consultant.

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