Not so Sweet: High-Sugar Diets Linked to Depression


If you have a tendency to indulge your sweet tooth, you may also be at risk for developing depression or anxiety, especially if you’re male.

In a study that spanned 30 years, more than 8,000 adults were regularly given questionnaires concerning their health and lifestyles starting in the 1980s. Anika Knüppel, of the University College London, said the study’s results weren’t what she was expecting.

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“I had a feeling we’d see the ‘Bridget Jones-like women eat chocolate’ idea,” Knüppel told New Scientist. “But it turns out people underestimate that men’s sugar intake is super high.”

The questionnaires were given to determine participants’ diet and intake of sweet food and beverages such as cakes, cookies, added sugar to coffee or tea, and soft drinks. The participants also took depressive symptom assessments throughout the study as well.

Sugar consumption was associated with socio-demographic factors, health behaviors and diet-related factors. Those who were placed in the highest category of sweet food and beverage intake were surprising, the study said.

“Unexpectedly, participants in the highest tertile of sweet food [and] beverage intake had the highest prevalence of normal weight and lowest prevalence of overweight and obesity as well as the lowest prevalence of abdominal obesity in men,” the authors wrote.

Related: Drinking Sugary Beverages While Pregnant Increases Child’s Obesity Risk

The study said there was an increased likelihood for incidents of common mental disorders in men and evidence of recurrent depression in both sexes with higher sugar intakes from sweet foods and beverages. The authors said they were able to exclude any potential reverse causation as the reason for the association between high sugar intake and low mood.

“Over years and decades, it could be that those susceptible to depression tend to increase their sugar intake. This group may tend to report higher consumption at study baseline even in the absence of depression at the time of the questionnaire, while having an increased risk of future depression compared to other participants,” the authors wrote. “However, there was no support for this alternative hypothesis, since the observed associations in our analysis were not the result of secondary changes in consumption of sugary food and drinks.”

Related: 6 Ways to Remedy Your Sugar Addiction

Knüppel said she thinks there could be a variety of reasons sugar affects someone’s mental health. Consuming a food or beverage with a high sugar content can cause a dip in their blood sugar later and could last longer.

She said sugar could also affect nerve cells by lowering proteins that help to develop and grow neurons in the brain. Diets with high sugar can also increase inflammation. Both stunted neuron growth and inflammation have been linked to depression.

“Our study provides evidence that sugar intake from sweet food/beverages increases the chance of incident mood disorders in men and limited evidence regarding recurrent mood disorders in both sexes,” the authors wrote. “With a high prevalence of mood disorders, and sugar intake commonly two to three times the level recommended, our findings indicate that policies promoting the reduction of sugar intake could additionally support primary and secondary prevention of depression.”