A popular non-nutritive sweetener may be an effective and human-safe insecticide, researchers have discovered in a study that began as a sixth-grade science fair project.
Erythritol, the main component of the sweetener Truvia, was toxic to Drosophila melanogaster fruit flies in a dose-dependent manner, researchers at Drexel University found.
The flies consumed erythritol when sugar was available and even seemed to prefer it. No other sweeteners tested had these toxic effects.
Based on this discovery, the researchers are pursuing a patent on erythritol as an insecticide and are continuing to study its effectiveness.
Erythritol is a naturally occurring sugar alcohol that is present in small amounts in many fruits.
It has been tested in humans at high doses and found safe to consume; it has been designated as a generally recognised safe food additive by the US Food and Drug Administration since 2001 and is also approved as a food additive in many other countries.
This line of research would not have started without the curiosity of one of the paper's co-authors, Simon D Kaschock-Marenda, who is now in the ninth grade.
Three years ago, Kaschock-Marenda questioned why both of his parents had stopped eating white sugar when trying to eat healthier.
"He asked if he could test the effects of different sugars and sugar substitutes on fly health and longevity for his science fair, and I said, 'Sure!" recalled Daniel Marenda, Simon's father and an assistant professor of biology in Drexel's College of Arts and Sciences - and now co-senior author of the study.
Father and son proceeded to buy supplies at their local supermarket - as many types of sugar and sugar substitutes as they could find.
Marenda's lab supplied "baby" flies and growth medium for his son to raise flies in each of the different types of sweeteners at home, in preparation for the science fair at the Julia R Masterman School in Philadelphia.
After six days of testing, all the flies in the Truvia vials were dead. Under more rigorous testing conditions in the lab, they replicated their result.
Marenda then collaborated with colleagues to test flies grown feeding on each of multiple non-nutritive sweeteners as well as sucrose (table sugar) and corn syrup.
Flies raised on food containing Truvia lived for only 5.8 days on average, compared to 38.6 to 50.6 days for flies raised on control and experimental foods without Truvia. Flies raised on food containing Truvia also showed noticeable motor impairments prior to their deaths.
"Indeed what we found is that the main component of Truvia, the sugar erythritol, appears to have pretty potent insecticidal activity in our flies," Marenda said.
The study was published in the journal PLOS ONE.
