Chronic increase in sugar consumption and visual attention in Wistar rats

Abstract

High sugar consumption is known to elevate the risk of obesity and related metabolic disturbances, but far less is known about its effects on cognition, learned behavior and mental health. Experimental findings in rodents indicate that increased sugar intake can induce cognitive impairment, most consistently in regard to memory functions. Studies examining the effects of an increase in dietary sugars on attention are lacking. The present study investigated the effects on visual attention of chronic high intake of sucrose and glucose in Wistar rats. Two groups of Wistar dams and their offspring were fed either a diet high in sugar, containing a high percentage of sucrose and glucose, or a standard sucrose/glucose diet. Attention was examined using a 3-choice-serial-reactiontime task. The present results demonstrated detrimental effects of high pre- and postnatal sugar consumption on visual attention in rats. The previously demonstrated memory impairments following increased sugar consumption may be mediated, at least partly, by attentional deficits. Future studies should investigate the translational relevance of these findings in humans, particularly in regard to mental disorders such as attention deficit/hyperactivity disorder (ADHD). Emerging evidence suggests that the mechanisms underlying the behavioral impairments related to diets high in sugar and/or fat may include neuroinflammation, changes of the blood–brain barrier and altered levels of brain-derived neurotrophic factor (BDNF). The elucidation of these mechanisms requires further investigations.