WILL SUGAR-FREE SWEETENERS COMBINED WITH SUGAR IN A MEAL IMPAIR METABOLISM? THIS STUDY SUGGESTS IT WILL.

It’s been debated ad nauseam whether or not sugar-free foods and drink that contain sweeteners like sucralose (like Diet Coke) have an effect on the metabolic rate and insulin sensitivity. 

A new paper in Cell Metabolism suggests that combining sucralose and carbohydratesimpairs insulin sensitivity.

What's Important: According to this study, it’s probably best to avoid consuming sucralose-sweetened drinks with a meal containing carbohydrates.

Practical Example: You sit down at a restaurant for a burrito bowl (rice, beans as your carbohydrates) and pair it with a Diet Coke.

Why Does It Matter?: many people opt for a soft drink sweetened with sucralose. Based on what this study tells us, it might be causing metabolic dysregulation.

This comes as a surprise given what we know about how low-calorie sweeteners and carbohydrates impact the metabolic rate. 

• It’s been shown that carbohydrates (sugar) alone does not inhibit insulin sensitivity.
• The same goes for sucralose alone as it has no negative impact on insulin sensitivity or metabolism.

The Details: In this paper, they showed that consuming 7 sucralose-sweetened drinks that also contained carbohydrate (sugars) over 10 days decreased insulin sensitivity in humans.

The interesting thing to note here is they found, when assessed with fMRI brain scans, that while insulin sensitivity was impaired, the taste perception (response to sweetness) was unaltered, suggesting a dysregulation of the gut-brain control in glucose metabolism.

Here’s a quick graph to see the impairment over 10 days in the brain.

This study was conducted with 45 humans, who were randomly assigned to consume 1 of 3 different beverages:

• sweetened with sucralose (no calories)
• sweetened with sugar (contains calories)
• sweetened with sucralose and sugar (maltodextrin, contains calories)

What to know: In the end, they determined after 10 days of consuming the beverages, that insulin sensitivity was not impaired for those consuming the sucralose sweetened drink and the sugar-sweetened drink.

But for those who consumed the drink containing both sugar and sucralose, they saw reduced insulin sensitivity and a blunted response to sugar in the brain.

Resource: https://www.cell.com/cell-metabolism/fulltext/S1550-4131(20)30057-7