Fewer teens are driving after drinking alcohol, but that concern may be replaced by a growing number of teens who are driving after smoking marijuana, a new study suggests.
Researchers at the University of Michigan looked at annual survey responses from 17,000 high school seniors between 2001 and 2011. In the most recent survey, 28 percent of seniors reported that within the previous two weeks, they drove after using drugs or having five or more alcoholic drinks, or had ridden in a car with a driver who had used drugs or drank. That was down from 32 percent a decade earlier.
However, teens who reported driving after smoking marijuana or accompanying a driver who had done so rose from 10 percent in 2008 to 12 percent in 2011. The increased rate of driving after marijuana use may also mean an increased risk of car crashes, the researchers wrote.
BOTTOM LINE: A growing number of teens report driving after smoking marijuana.
CAUTIONS: The study relies on self-reported survey results, which may not be accurate. The study did not look into whether marijuana use before driving led to impaired driving or crashes.
WHERE TO FIND IT: American Journal of Public Health, Sept. 12.
Fitness may boost memory, learning in some children
Exercise may help children learn and memorize challenging material, University of Illinois researchers report.
For the study, 48 children ages 9 and 10 were divided into two groups: One consisted of children who scored in the top 30 percent on a test measuring their aerobic fitness level on a treadmill, and the second group scored in the lowest 30 percent.
Both groups were asked to memorize names and locations on two maps, using different strategies for each. The first strategy involved the children being tested on the material as they studied, while the other strategy involved only memorization.
When tested the next day, children in the high-fitness group were better able to learn and recall names and locations on a map they used a memorization-only strategy to learn, compared with the children in the low-fitness group using the same strategy. There was no difference in scoring between both groups on the map where they were tested as they studied.
The memorization-only strategy is a more challenging way of learning, according to the researchers.
The findings suggest that perhaps the brains of high-fitness children are able to retain information better than the brains of children who are more sedentary, the researchers wrote.
BOTTOM LINE: Exercise may help boost learning and memory in children ages 9 and 10.
CAUTIONS: The study involved a small number of children, so the results may not apply to a wider group. The study cannot determine a cause and effect relationship between the children’s fitness level and their level of learning.
WHERE TO FIND IT: PLOS ONE, Sept. 11.