Hummingbirds Metabolism Equally Burns Glucose and Fructose

Have you ever marveled at the flight of a hummingbird, as its little wings beat 80 times per second! Well, a recent study also looks at the magic of this creature's metabolism.

New research from the University of Toronto Scarborough shows that these birds are equally adept at burning glucose and fructose, a unique trait not seen in any other vertebrates.

"Hummingbirds have an optimal fuel-use strategy that powers their high-energy lifestyle, maximizes fat storage and minimizes unnecessary weight gain all at the same time," Kenneth Welch said via a press release, an assistant professor of biological sciences at UTSC and an expert on hummingbirds.

For the study, researchers fed hummingbirds separate enriched solutions of glucose and fructose while collecting exhaled breath samples. They found that the birds were able to switch from burning glucose to fructose equally.

"What's very surprising is that unlike mammals such as humans, who can't rely on fructose to power much of their exercise metabolism, hummingbirds use it very well. In fact, they are very happy using it and can use it just as well as glucose," Welch said, via the release.

Welch notes that from an evolutionary perspective, these findings make sense. Just as humans evolved over time on a complex diet, hummingbirds evolved on a diet rich in sugar.

"Hummingbirds are able to move sugar from their blood to their muscles at very fast rates, but we don't yet fully understand how they are able to do this," he adds, via the release.

Though humans are not good at burning fructose because once ingested, much of it turns to fat, hummingbirds can burn sugar so fast that if they were the average person, they would need to drink more than one soda every minute!

"If we can gain insights on how hummingbirds cope with an extreme diet then maybe it can shed some light on what goes wrong in us when we have too much fructose in our diet," Welch said, via the release.

What do you think?

More information regarding the study can be found via the journal Functional Ecology.