Sugar just crossed the line from being a diet hazard into actually changing the way the brain processes stress. Researchers from Emory University School of Medicine have revealed how the dangers of the simple sugar fructose can go deeper than just an unhealthy diet. After discovering that a diet thickly laced with sugar can worsen depression or anxiety in kids and teens, they presented their findings at Neuroscience 2014’s annual meeting.

"Our results offer new insights into the ways in which diet can alter brain health and may lead to important implications for adolescent nutrition and development," the study’s lead author Constance Harrell of Emory University in Atlanta, said in a press release. Harrell presented her work at the conference themed, “Unhealthy diet, unhealthy mind,” and showed an uglier side to the sweetness in young diets. Fructose is a sugar found rampantly throughout packaged foods and beverages and could be changing the way teens handle stress at school and home.

Harrell and her research team compared how stress hormones changed in adolescent and adult mice when they were placed on a particular diet. After 10 weeks, the adolescent rats on high-fructose diets were reacting differently to stress. They were depressed and the pathway in their brain that responds to stress had been changed. Adult mice that had been eating sugar weren’t affected, and neither were the adults and adolescents that were eating standard balanced meals.

Fructose is a type of sugar found naturally in some fruits and vegetables, but it isn’t digested the same way glucose is digested. Fructose and glucose are both simple sugars, but glucose is the body’s preferred energy source. Meanwhile, fructose causes insulin to be released and stimulates the hunger hormone leptin and actually acts more like fat in the body. Fructose’s influence on teens goes beyond the stomach, and now that researchers know its potential harm to their growing brains, diet therapies may be a way to curb stress.

Teenagers in America report experiencing stress at levels comparable to adults, according to the American Psychological Association (APA). Teens report their stress levels to be much higher than the levels considered to be safe. By combining a bad diet in with the social and academic pressures teens face every day, it could be a recipe for depression and anxiety disorders. Even though a high fructose diet didn’t affect the adult rats, the adolescent rats could grow up to be more susceptible to anxiety and depressive issues.

“It is alarming that the teen stress experience is so similar to that of adults. It is even more concerning that they seem to underestimate the potential impact that stress has on their physical and mental health,” APA CEO and Executive Vice President Norman B. Anderson said in a press release. “In order to break this cycle of stress and unhealthy behaviors as a nation, we need to provide teens with better support and health education at school and home, at the community level and in their interactions with health care professionals.”

Source: Harrell CS, Heigh GN, Burgado J, Kelly SD, and Johnson ZP. Developmental high-fructose diet consumption increases depressive-like and anxiety-like behavior and remodels the hypothalamic transcriptome. Neuroscience 2014. 2014.