US teen usage of marijuana remains high. The University of Michigan released the results of a study on U.S. teens and marijuana use. The survey included about 45,000 students in grades 8, 10 and 12 in schools across the country. The results found that 22.9 percent of high school seniors said they had used marijuana within the previous 30 days and 16.6 percent had used a vaping device.The results also showed that marijuana use was up overall about one percent. However, the study raised concerns about the popularity of vaping devices, which are perceived by some experts as a healthier alternative to traditional cigarettes because they don’t include carcinogens that come with burning tobacco. The devices are typically sold with nicotine, but when 12th-graders were asked what they thought was in the vapors, 51.8 percent said “just flavoring.” While noting that the data on vaping devices as a gateway to cigarettes is inconclusive, some researchers are watching this trend carefully. 

Sugary diet during pregnancy increases asthma risk. A new study published in the Annals of the American Thoracic Society looked at the link between poor diet and obesity and current increases in childhood asthma. Harvard researchers studied 1,068 mothers, gathering diet information during their pregnancies. They checked children’s diet and asthma diagnoses at ages 3 and 7. Compared with the children of women who consumed the least sugar (an average of 21 grams a day) the children of those who had the most (46 grams a day) had a 58 percent higher risk for asthma. The authors are unsure of the causes for the association but implicate sugary drinks and fructose, or fruit sugar.