Low Total Cholesterol Levels and Performance on the Iowa Gambling Task

Very low levels of systemic total cholesterol (TC) may have adverse neurological consequences, and there is a lack of research investigating how TC levels are related to specific aspects of behavior and cognition. This study examined the relationship between low TC levels and performance on the Iowa Gambling Task (IGT), a standardized measure of decision making. Fasting plasma TC levels were measured in 61 healthy female university undergraduates, various demographic and health measures were obtained, and each participant completed the IGT. Individuals with TC < 140 mg/dL performed significantly more poorly on the IGT than those with TC ≥ 140 mg/dL (p = 0.01). On the IGT, participants with TC levels < 140 mg/dL persisted in preferentially responding to task stimuli with large and immediate monetary gains, despite the fact that these gains were yoked to increasing and unpredictable losses over time. This difference cannot be attributed to dissimilarities in BMI or general health between the groups. These findings indicate that TC levels < 140 mg/dL are associated with significant impairments in decision making and heightened behavioral impulsivity. Negative cognitive and behavioral outcomes with “real-world” relevance may be associated with very low TC levels.