Sleep and Memory: How Drink Sweetness Affects Bedtime

Have you ever thought about how the sweetness of your evening drink might impact your night's sleep and memory? A recent study explored this by comparing the effects of a low glycemic index (LGI) drink to a high glycemic index (HGI) drink on the sleep and memory of healthy men. The LGI drink contained isomaltulose, which is slowly digested, while the HGI drink had glucose, which is quickly absorbed. Twenty healthy males participated in the study, visiting a lab three times over a few weeks. They consumed a standard dinner followed by one of the two drinks four hours later. Their sleep was monitored using polysomnography, and their memory was tested before and after sleep using tasks like finger tapping and story recall. Interestingly, the type of drink didn't make a big difference overall. But when the men drank the LGI drink on their second visit, they experienced more deep sleep (also known as N3 sleep) and better memory retention for neutral stories compared to when they drank the HGI drink first. This suggests that the type of carbohydrate in your pre-bedtime drink can influence both the quality and quantity of your sleep, as well as how well you remember things. The study was pre-registered with ClinicalTrials. gov (NCT05591573).