Eating Refined Carbs and Junk Food Can Cause Depression

Avoiding high-glycemic foods may treat and prevent mood swings and depression.

Depression is one of the most common mental disorders in the U.S., affecting almost 7 percent of Americans, according to the National Institute of Mental Health. Persistent feelings of sadness and pessimism can interfere with work and your enjoyment of life, but depression can often be effectively treated with psychotherapy, exercise, and medication. And now research from Columbia University Medical Center suggests another strategy. 

It turns out that changing your diet can decrease bad moods and potentially treat and even prevent depression.

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The key, according to James Gangwisch, PhD, who headed the study, is to kick most refined carbohydrates (which lack fiber) and junk food containing added sugar out of your life. Gangwisch and his colleagues found that eating refined carbs like white bread, cakes, chips, candy, and sweetened cereals is associated with an increased risk for depression to develop in the first place. 

These are foods with a high-glycemic index, which means they cause a rapid surge of blood glucose levels after you eat them. “Foods that tend to have a lot of fiber like beans, yams, nuts have a low glycemic index whereas foods that are more processed, where all that fiber is removed — white bread, white rice, candies, cakes, sweetened beverages — those have higher glycemic indexes,” Gangwisch explained in a video interview.

Eating high-glycemic foods often results in what is often called a sugar “high.” Your body quickly reacts, releasing the hormone insulin to take the excess glucose out of your blood and move it into the liver, muscle, and fat storage.

“Unfortunately, it can bring blood sugar down too low,” Gangwisch, an assistant professor of psychiatry at Columbia, said. “Then we can have a stress hormone response in an effort to bring that blood sugar back up and that stress hormone response can cause symptoms such as anxiety and irritability. When glucose levels to our brain are jeopardized, then we can have difficulty focusing and concentrating, mood and behavioral changes and hunger.” 

The Columbia research team analyzed data from more than 70,000 postmenopausal women who participated in the National Institutes of Health’s Women’s Health Initiative Observational Study between 1994 and 1998, and who were not depressed when the study began. The investigators looked at the women’s diets, focusing on the glycemic index of the foods consumed, and symptoms of depression in the study participants. 

The result of the Columbia research revealed the women who ate high-glycemic index foods had a higher risk of new-onset depression. However, there was a decreased risk of developing depression among women who frequently ate lower-glycemic index foods rich in fiber. 

Previous studies looking at the diets of men and younger women also found that higher-glycemic index foods were associated with depression, Gangwisch noted.

“If higher-glycemic index diets increase the risk for depression, then consuming a lower-glycemic index diet could lower your risk for depression and could potentially be a treatment for depression,” he concluded. 

If you are suffering from depression and find yourself eating a lot of sweets and refined carbs, that’s understandable. Eating those foods can make you feel better momentarily and that’s why it can be difficult to stop consuming them, according to Gangwisch.

However, if you keep eating high-glycemic goodies, you’ll trigger highs and lows in your blood sugar and ultimately a lower mood. To break this cycle, you need to change your diet and not reach for sweets and carbs as quick pick-me-ups. 

“Putting the effort into trying to give them up and to replace those foods with more healthy alternatives can potentially pay dividends in terms of how you feel and your mood.“ Gangwisch said.