School ban on sugary drinks shows little effect

NEW YORK (Reuters Health) - Policies that rid Maine high schools of sugary drinks seem to have had little impact on teenagers' overall intake of sugar-laden beverages, according to a new study.

The study compared four high schools that eliminated soda and other sugar-sweetened drinks from cafeterias and vending machines with three schools that did not take such measures.

Researchers found that over one school year, students in both groups of schools cut down on their average daily intake of sugary drinks -- but there was no evidence that the school soda bans led to greater reductions.

The reasons for the findings are not clear, and the study does not mean that getting sugar-laden drinks out of schools is a waste of time, according to the researchers.

Lead researcher Dr. Janet E. Whatley Blum said she would not conclude that such school policies are "ineffective" based on these findings.

Students' consumption of sweet drinks did go down, she told Reuters Health; the study just failed to find a statistically significant difference between schools that cut back on sweetened beverages and those that did not.

Several limitations of the study might help explain the finding, noted Blum, an associate professor at the University of Southern Maine, in Gorham.

One is that students were followed for only nine months, which might not be a long enough period to see substantial effects. Another is that the study included only high schools; similar policies in elementary and middle schools might be more effective since younger children have less freedom to buy sugary treats on their own.

The study, published in the Journal of Nutrition Education and Behavior, included four Maine high schools that had banned the sale of sugar-sweetened drinks, with the exception of one school that allowed sports drinks to remain in vending machines.

The schools replaced these beverages by selling more milk, water and fruit juice.

Blum's team surveyed 235 students about their daily intake of sugary drinks at two time points: the spring before the school policies took hold and nine months after they went into effect. The researchers gave the same survey to 221 students at high schools that kept selling soda and other sugar-added drinks.

On average, the study found, students at both groups of schools curbed their intake of sugary beverages to a similar degree over the school year.

According to Blum, keeping such drinks out of teenagers' reach during school hours may not be enough.

"School appears to be just one source of sugar-sweetened beverages for youth," she said, "and it may be that an educational component...is needed to have an effect on consumption from sources other than school."

SOURCE: Journal of Nutrition Education and Behavior, November/December 2008.