Sugary coffee drinks tied to poor sleep for young women

Nearly half of all young women in a small U.S. study said they were poor sleepers, and those who drank sugary coffee beverages and energy drinks tended to have the worst sleep quality.

“Young adulthood is a time of intense change that influences health behaviors,” said Deborah Rohm Young, director of behavioral research at Kaiser Permanente Southern California in Pasadena. “We were specifically interested in sleep quality because not much research has been conducted on sleep and other health behaviors in young adults.” To explore this question, the researchers analyzed responses from 462 women who had participated in a long-term study as teenagers, beginning in 2006.

In 2015, the women answered a sleep quality questionnaire to rate their sleep duration, how often they wake up during the night, how long they take to fall asleep and any use of sleep medications. Sleep quality scores were calculated based on seven aspects of sleep.

Overall, 45.2% of the young women had scores indicating poor sleep quality.

Beverage habits were assessed using a survey that asked the women how often they drank soda, sports drinks and sweetened coffee-based drinks like mochas or frappuccinos over the past seven days.

Women who said they consumed energy drinks or high-calorie coffee beverages were more likely to report poor sleep quality, the authors report in the journal Sleep Health.

Two findings stand out, Young said.

“First, that prevalence of poor sleep quality was so high - almost half of the participants reported poor sleep quality,” she noted. “Second, that (consuming) sugary coffee drinks, even some compared with none, was associated with poor sleep quality.” The study wasn’t designed to prove that coffee-based drinks caused the women’s sleep problems. And it’s possible, the authors note, that sleep problems may lead to consuming sugary caffeinated drinks by day, which may lead to more sleep problems.

The relationship between sugar and caffeinated beverage intake and sleep is complicated, according to Dr. Suzanne Bertisch, clinical director of Behavioral Sleep Medicine at Brigham and Women’s Hospital in Boston, who wasn’t involved in the study.

“Consuming beverages with caffeine and sugar may be a sign that people are not getting the quality and quantity of sleep they need, but also may be a factor in causing poor sleep,” Bertisch told Reuters Health by email.

Factors other than diet could also account for poor sleep in young women, said Bertisch. A strength of the paper was that it accounted for the influence of parenting roles and employment status, she said.

“Other factors to consider are those related to mood, such as stress, anxiety, and depression; and medical conditions like migraine, which has high prevalence among young women.” The authors did not collect information about women doing shift work, which may also impact sleep, diet and caffeine intake, Bertisch noted.

Young pointed out that sleep quality scores were only modestly worse among women who consumed sugary caffeine drinks compared to those who didn’t, and future studies are needed to determine if drinking sugary coffee drinks affects sleep quality.