ADHD News & Research

ADHD and Sugar Study: High Fructose Consumption May Trigger Impulsivity, Aggression

A new study expands our understanding of the relationship between ADHD and sugar — specifically how an excessive intake of fructose may trigger foraging instincts that cause impulsivity and aggression.

October 19, 2020

Sugar intake has been linked to several behavioral disorders, including attention deficit hyperactivity disorder (ADHD or ADD) and bipolar disorder, but the nature of this association has remained unclear until recently. A new study published in the journal Human Evolution and Behavior1 proposed that hyperactivity, impulsivity, and mania come from ancient foraging instincts triggered by a high or excessive intake of fructose.

Researchers explored the role of fructose and uric acid (a fructose metabolite) in increasing the risk for certain behavioral disorders. They referenced and largely confirmed previous research that found fructose intake — largely from fruits and honey — to trigger “an evolutionary-based survival pathway that stimulates foraging behavior” as well as the storage of energy as fat, suggesting a link between metabolic syndrome and high levels of sugar intake.

Fructose lowers the energy in cells, causing a response similar to starvation. While some fructose may help animals store fat as a protective measure from starvation, researchers suggest that high intake — in excess of FDA recommendations2 — causes a “hyperactive foraging response that stimulates craving, impulsivity, risk taking, and aggression that increases the risk for ADHD, bipolar disease, and aggressive behavior,” according to the new research from the University of Colorado Anschutz Medical Campus.

Researchers also found evidence that high-glycemic carbohydrates and salty foods might contribute to the risk for impulsivity and aggression since they can be converted to fructose during metabolism.

These findings are significant for understanding the role that sugar consumption plays in causing and/or exacerbating symptoms of ADHD. Though added sugars should comprise less than 10% of total daily calories, the CDC found that Americans (aged 6 and older) consumed around 14% of total daily calories from added sugars in 2003-2010.3


1Johnson, Richard, et al. Fructose and uric acid as drivers of a hyperactive foraging response: A clue to behavioral disorders associated with impulsivity or mania? Human Evolution and Behavior (Oct. 2020).

2Statement on new guidance for the declaration of added sugars on food labels for single-ingredient sugars and syrups and certain cranberry products. Food and Drug Administration (Jun. 2019).

3Know Your Limit for Added Sugars. CDC (2019)