Pop and violence?

Regardless of whether you call it soda, pop, or a soft drink, do you think it might cause violent behavior? In “Does Soda Cause Violence? Teens who drink soda may be more likely to get into fights and act violently,” Emily Sohn of Discovery News goes pretty far along the path to answering in the affirmative.

Teenagers who drink lots of soft drinks get into more fights and carry more weapons than their peers who drink less, found a new study.

And while the study couldn’t determine whether soft drinks actually cause violence, the findings add to a growing — yet still controversial — body of research on the effects of nutrition on behavior.

“We were surprised at how large the effect was,” said David Hemenway, director of the Harvard School of Public Health’s Injury Control Research Center in Boston.

Ms. Sohn goes on to describe Sara Solnick and Professor Hemenway’s survey of teens’ self-reported consumption of non-diet soft drinks and whether they had carried a weapon or engaged in physical violence with a peer. They reported a significant positive correlation between soft-drink consumption and violent behavior.

Ms. Sohn cites other evidence arguing for a diet-behavior connection, leaving one with the overall impression that she sees a causal relationship between soft-drink consumption and violent behavior. In her report, to her credit, she found another expert who explained that the study was, indeed, reporting a correlation (and the original authors note this in their abstract as well), but the thrust of her article is toward causation; the comments show that other readers concur with my impression.

As reasonable readers of the research know, however, questions about diet and behavior have been extensively researched and many popular ideas have proven unfounded. For example, the idea that sugar causes children to act “hyper” simply can’t be established except anecdotally.

For example, Mark Wolraich and colleagues conducted a double-blind design with lots of families in which the families’ diets were closely controlled (e.g., food stuffs removed from house, meals prepared by the research project). Over many weeks, families ate foods that were sometimes sweetened by sugar and sometimes sweetened by two artificial agents; they got these special diets in different orders. Differences in the sweeteners did not affect children’s activity level or several other measures.

Why do all the cousins seem to get yippity-skippity right after eating desert when they’re at grandma’s house? Hmmmm…. suddenly they’re free to leave the table and run amok? They’re hanging with cousins which only happens every so often? There are new and different things to do? The adults will all be sitting around the table for a while longer, so supervision will be minimal?

Oh, shoot. It’s easier to point the finget at the food! Here’s the link to Ms. Sohn’s article, Does Soda Cause Violence?

Solnick, S. J., & Hemenway, D. (2011). The ‘Twinkie Defense’: the relationship between carbonated non-diet soft drinks and violence perpetration among Boston high school students. Injury Prevention, PMID: 22025524

Wolraich, M.L., Lindgren, S.D., Stumbo, P.J, Stegink, L.D., Applebaum, M.I., & Kiritsy, M.C. (1994) Effects of diets high in sucrose or Aspartame on the behavior and cognitive performance of children. New England Journal of Medicine, 330, 301-307.