The impact of nutritive and non-nutritive sweeteners on the central nervous system: preliminary study

Nutr Neurosci. 2021 Feb 28;1-10. doi: 10.1080/1028415X.2021.1885239. Online ahead of print.

Abstract

Background: Human consumption of food and beverages containing added nutritive or non-nutritive sweeteners has increased worldwide.

Objective: The present study evaluated the possible impact of frequent sweetener consumption on human CNS activity and functions through neuropsychological testing and EEG/qEEG analysis.

Methods: A sample of 23 women and 16 men, aged 18-35, with a body mass index between 18 and 24.9 kg/m2 was evaluated. Participants underwent a 1-week washout period in which food with added sugars or sweeteners was restricted from their diet. Initial assessment of cognitive functions was performed with a validated neuropsychological test and EEG/qEEG analysis, prior to supplementation. Sucrose, sucralose, or steviol glycosides, in commercially available presentations, were randomly assigned to three experimental groups of 13 participants each. Sweeteners were supplemented in fixed amounts, daily, for six weeks. After supplementation, neurological tests were repeated and the initial and final results were compared.

Results: The results show no significant changes between final and initial measures in the steviol glycosides group. However, a significant decrease in encoding memory was found in the sucrose group in the final evaluation. Strikingly, the sucralose group showed a significant decrease in overall memory, encoding memory, and executive functions after supplementation. Furthermore, qEEG analysis showed an increase in theta wave absolute and relative power at the final evaluation in the same group.

Conclusion: These data show that frequent consumption of specific sweeteners is accompanied by measurable changes in EEG/qEEG activity and neuropsychological test performance in humans.

Keywords: Sweeteners; central nervous system; encoding memory; exeutive functions; neuropsychological testing; non-nutritive sweeteners; over all memory; qEEG.