Do Soft Drinks Play a Role in Adolescent Suicide?

Suicide is the fourth leading cause of death among 15- to 29-year-olds worldwide and the second leading cause of death among 10- to 34-year-olds in the U.S. Commonly studied risk factors for adolescent suicide include depression, acute stressful events, chronic adversity in early life, reduced physical activity, and genetic factors. Diet is also thought to play an important role.

Past studies in non-U.S., low- and middle-income countries have reported that the consumption of sweetened beverages is highly correlated to loneliness, sedentary behaviors, unhealthy weight, aggressive behaviors, poor mental health, and suicidality among adolescents. The youth of the entire world, including the U.S., spend a significant amount of time being sedentary and drinking soft drinks. A recent study investigated the relationship between consuming soft drinks and being inactive to the risk of suicide in the U.S.

The study first determined whether the subjects met the WHO recommendations for physical activity (i.e. how many of the past seven days the subjects were physically active for a total of at least 60 minutes per day), computer screen time, and nightly sleep duration. The study assessed whether the subjects met all three criteria or whether they met the criteria for physical activity and screen time, or physical activity and sleep duration, or screen time and sleep duration—or for physical activity only, screen time only, sleep duration only, or none of the three criteria.

The study also considered the role of demographic factors such as age, sex, race, and BMI. The study included data from five recent 10-year surveys (2011, 2013, 2015, 2017, and 2019) of students in grades 9 through 12 and ultimately included a total of 73,074 adolescent subjects. Eighty-eight percent of these subjects were over 15 years of age, 50 percent were males, and about 28 percent were overweight or obese.

The study also considered specific dietary behaviors, such as the intake of vegetables, fruit, milk, and daily breakfast consumption. [For more about the connection between diet and depression, go here.] Depressive symptoms were determined by asking the subjects whether, during the past 12 months, they ever felt so sad or hopeless for two weeks or more in a row that it prevented them from participating in their usual activities.

The Negative Impacts of Soft Drink Consumption

The frequency of soft drink consumption significantly correlated with the prevalence of suicidal ideation, making a suicide plan, and having attempted suicide. For both the boys and the girls, the linkage was greatest when soft drink consumption was greater than three drinks per day.

Girls who reported consuming soft drinks only 1 or 2 times each day had an increased risk of suicidal ideation. And in contrast to the boys, the girls showed no statistically significant association between meeting the 24-hour movement guidelines and suicidality. Meeting the movement guidelines was more important for the boys with regard to vulnerability to suicide.

Fortunately, the boys had a higher prevalence of meeting the movement guidelines. But in contrast to the girls, not meeting all the recommendations of the movement guidelines significantly increased the risk of suicidal ideation and suicide attempts among the boys.

Overall, the results of this study emphasize the importance of reducing the daily consumption of soft drinks for the prevention of suicide in adolescents—and this appears to be particularly true for boys who do not get enough sleep or daily physical activity.