The study, published in the American Journal of Public Health, raised the price of sugary soft drinks in the university canteen by 35 percent for a four week period – about the same effect as a penny-per-ounce tax.
While sales of regular soft drinks fell, sales of diet soft drinks and coffee increased by 20 percent, they found, suggesting that higher prices for caloric drinks may encourage many people to switch to healthier alternatives.
“Policymakers and public health advocates have proposed the taxation of regular soft drinks as a means to reduce the consumption of these products and raise revenue for public health purposes,” the study’s authors said. “Our results may have implications for these proposed policies.”
The researchers also conducted a four-week education campaign in which they posted flyers and posters around campus that read: “Lose up to 15-25 pounds in one year and decrease your risk of diabetes by 1/2. Just skip one regular soda per day. For zero calories, try diet soda or water."
They reported no difference in consumption levels of sugary drinks with this approach. However, a combination of increased prices and flyers was associated with a further 18 percent drop in consumption of caloric soft drinks.
“Future research should test price increases on fruit juices and other sugary beverages and should examine several price levels to determine what price increase is most effective in reducing sugary beverages sales while maintaining revenue neutrality for a cafeteria or food establishment,” the authors said.
The American Beverage Association, which has strongly opposed beverage taxes, said that reducing consumption of sugary beverages was “a simplistic and ineffective solution to public health challenges”.
President and CEO of the ABA Susan Neely said: “Singling out one item as the cause of obesity completely misses the mark. If we really want to solve this national public health challenge, we must focus on educating Americans through comprehensive approaches that include nutrition education based in fact and focusing on total diet and exercise - not efforts that are simplistic and will be ineffective."
Source: American Journal of Public Health
Published online ahead of print June 17, 2010: e1–e7.doi:10.2105/AJPH.2009.175687
“Point-of-Purchase and Education Intervention to Reduce Consumption of Sugary Soft Drinks”
Authors: Jason Block, Amitabh Chandra, Katherine McManus, and Walter Willett.