Early-life sugar consumption has long-term negative effects on memory function in male rats

Abstract

Objectives: Added dietary sugars contribute substantially to the diet of children and adolescents in the USA, and recent evidence suggests that consuming sugar-sweetened beverages (SSBs) during early life has deleterious effects on hippocampal-dependent memory function. Here, we test whether the effects of early-life sugar consumption on hippocampal function persist into adulthood when access to sugar is restricted to the juvenile/adolescent phase of development.

Methods: Male rats were given ad libitum access to an 11% weight-by-volume sugar solution (made with high fructose corn syrup-55) throughout the adolescent phase of development (post-natal day (PN) 26–56). The control group received a second bottle of water instead, and both groups received ad libitum standard laboratory chow and water access throughout the study. At PN 56 sugar solutions were removed and at PN 175 rats were subjected to behavioral testing for hippocampal-dependent episodic contextual memory in the novel object in context (NOIC) task, for anxiety-like behavior in the Zero maze, and were given an intraperitoneal glucose tolerance test.

Results: Early-life exposure to SSBs conferred long-lasting impairments in hippocampal-dependent memory function later in life- yet had no effect on body weight, anxiety-like behavior, or glucose tolerance. A second experiment demonstrated that NOIC performance was impaired at PN 175 even when SSB access was limited to 2 hours daily from PN 26–56.

Discussion: Our data suggest that even modest SSB consumption throughout early life may have long-term negative consequences on memory function during adulthood.

GRAPHICAL ABSTRACT

Keywords:

• Sugar-sweetened beverages
• SSB
• Obesity
• Hippocampus
• Programming
• Adolescence
• Fructose

Acknowledgements

We would like to thank Andrea Suarez, Clarissa Liu, Alyssa Cortella, and Lilly Taing for their tremendous assistance with data collection.

Additional information

Funding

Our funding sources are: National Institute of Diabetes and Digestive and Kidney Diseases DK104897 (SK), University of Southern California Diabetes and Obesity Research Institute (SK), and National Institute of Diabetes and Digestive and Kidney Diseases F32-DK111158 (EN).