New Study Sheds Light On How Artificial Sweeteners Impact Water And Ecosystems

The human body cannot break down sucralose, an artificial sweetener in many zero-calorie foods and drinks. Scientific research has shown that this compound is so stable it remains intact through wastewater treatment processes, ending up in drinking water and aquatic environments.

"We can't break down sucralose, and a lot of microorganisms can't break it down, either, because it's a really tough molecule that doesn't degrade easily. So there are a lot of questions about how it is affecting the environment and whether it's something that could impact our microbial communities," said Tracey Schafer, an assistant research scientist for the University of Florida's Whitney Laboratory for Marine Bioscience and the soil, water and ecosystem sciences department, part of UF's Institute of Food and Agricultural Sciences.

Impact on Aquatic Microorganisms

Schafer co-authored a study examining sucralose's effects on cyanobacteria and diatoms. Cyanobacteria are aquatic photosynthetic bacteria, while diatoms are microscopic algae responsible for over 30% of primary food production in marine ecosystems. The findings were published in Environmental Monitoring and Assessment.

Researchers gathered soil and water samples from freshwater and brackish sites in Marineland, Florida. At their St. Augustine lab, they exposed these samples to varying sucralose concentrations. They then measured photosynthesis and microbial respiration at intervals: every four to six hours within a day and every 24 hours over five days.

Freshwater vs Brackish Water Reactions

Compared to control groups, freshwater cyanobacteria concentrations rose when exposed to sucralose. However, brackish cyanobacteria levels initially spiked but later crashed under similar conditions.

"There is the potential that the freshwater communities might be mistaking sucralose for a nutrient, for a sugar that they can use as food," said Amelia Westmoreland, the study's lead author who worked on the project during her undergraduate chemistry degree.

Both freshwater and brackish diatoms showed an overall population decrease when exposed to sucralose compared to control groups. This decline was more significant in freshwater experiments.

Potential Ecosystem Threats

Sucralose's dual ability to increase or decrease microbial populations could disrupt natural ecosystem balances. "Extreme examples of how this could play out are the diatom community could disappear, and the other extreme is this community could completely overtake everything else," Westmoreland noted.

Schafer emphasized the need for further studies to fully understand sucralose's environmental impact. "I think this study was a good first step in starting to look at how sucralose could impact our aquatic communities, and hopefully it will drive more research forward," Schafer said.