The holiday season is a time for family, friends, and not least of all, cookies. However, people who are prone to depression might want to pass up on the sweets, according to study results published in Medical Hypotheses.1
Examining a Potential Link Between Sugar and Depression
A team of researchers at the University of Kansas hypothesized that high levels of sugar intake may increase the risk for major depressive disorder (MDD). To test their hypothesis, they scoured research on the physiological and psychological effects of consuming added sugar, which is present in many holiday treats.
“Although excessive sugar consumption is now robustly associated with an array of adverse health consequences, comparatively little research has thus far addressed its impact on the risk of mental illness,” the authors explained. Maladaptive dietary habits “pose an obvious threat to physical well-being” and “carry the potential to endanger psychological health.”
The investigators reviewed data from several large epidemiological studies including the Women’s Health Initiative Observational Study and the NIH-AARP Diet and Health Study. They also analyzed data from cross-sectional surveys of soda drinkers.
The researchers found that consuming too much sugar can trigger numerous inflammatory, metabolic, and neurobiological processes linked to depression. “Multiple distinct lines of evidence generally converge in suggesting that the consumption of added sugars may induce depressogenic effects,” they wrote.
Inflammation, they found, was a critical physiological effect of dietary sugar intake. “Added sugars have a profound effect on inflammatory processes within the body and brain, and inflammation may serve as a key mediator of sugar-induced depression onset.”
The researchers also found that sugar affects the release of dopamine. “Interestingly, acute sugar consumption tends to stimulate the [dopamine] system.” It also alters the structure and function of dopamine pathways, a “pathology consistent with the observed connection between [dopamine] dysregulation and depression.”
“When we consume sweets, they act like a drug,” explained Stephan Ilardi, associate professor of clinical psychology at the University of Kansas. “They have an immediate mood-elevating effect, but in high doses they can also have a paradoxical, pernicious longer-term consequence of making mood worse, reducing well-being, elevating inflammation, and causing weight gain.”2
While the link between added sugar and depression is “neither definitive nor conclusive,” the evidence to date is compelling, the authors concluded. “Much more extensive investigation will be necessary, of course, to fully elucidate the sweetener’s hypothesized depressogenic potential in humans.”1
- Reis DJ, Ilardi SS, Namekata MS, Wing EK, Fowler CH. The depressogenic potential of added dietary sugars. Med Hypotheses. 2019;134:109421.
- Lynch BM. Want to avoid the holiday blues? New report suggests skipping the sweet treats. University of Kansas website. Published December 12, 2019. Accessed December 16, 2019.