美国研究人员称嚼口香糖可以帮助学生集中注意力，从而有助青少年提高数学成绩。这样的结果估计要让严令禁止学生嚼口香糖的学校管理人员大跌眼镜了。该研究是由口香糖巨头箭牌公司资助并由休斯敦贝勒医学院的克莱格？约翰斯顿主持进行的。经过为期14周的对比实验后，研究人员发现在课堂、考试以及家庭作业时嚼口香糖的学生最后的数学考试成绩要高于那些没有嚼口香糖的学生。

    In a study likely to make school janitors cringe, U.S. researchers said Wednesday that chewing gum may boost academic performance in teenagers.

    Many U.S. schools ban chewing gum because children often dispose of the sticky chaw under chairs or tables.

    But a team led by Craig Johnston at Baylor College of Medicine in Houston found that students who chewed gum during math class had higher scores on a standardized math test after 14 weeks and better grades at the end of the term than students in the class who did not chew gum. The study was funded by chewing gum maker Wrigley.

    "For the first time we've been able to show in a real-life kind of situation that students did perform better when they were allowed to chew," said Gil Leveille, executive director of the Wrigley Science Institute, a research arm of Wm Wrigley Jr Co, which is now a part of Mars Inc.

    Leveille said Wrigley has gotten feedback from many of its gum customers who say chewing gum helps them stay focused.

    So, four years ago the company started the science institute to see if some of these claims have merit.

    The researchers at Baylor studied four math classes or 108 students aged 13 to 16 years old from a Houston, Texas, charter school that serves mostly low-income Hispanic students.

    About half got free Wrigley's sugar-free gum to chew during class, homework and tests. They chewed at least one stick of gum 86 percent of the time they were in math class and 36 percent of the time they were doing homework.

    The other half went without.

    After 14 weeks, the gum chewers had a three percent increase in their math scores on the Texas Assessment of Knowledge and Skills achievement test, a small but statistically significant change, according to Johnston and colleagues, who presented their findings at the American Society for Nutrition scientific meeting in New Orleans.

    They found no difference in math scores between the two groups in another test called the Woodcock Johnson III Tests of Achievement. However, the gum-chewers did get better final grades in the class than their non-chewing peers.

    Another Wrigley-funded study found that college students in a lab who were given difficult computer tasks had lower levels of the stress hormone cortisol when they were chewing gum compared to when they were not.

    Leveille said he thinks chewing gum helps reduce stress so students can do their best work. And while he is aware that many schools have a dim view of students chewing gum in class, he hopes the findings may change that a bit.

    "It's not a matter of chewing. It's a matter of gum disposal," Leveille said, adding that that can be overcome by teaching proper disposal behaviors.

    If that fails, he quipped, "We'll have to provide the janitors with scrapers."