For many people, the term "diabetes" strikes fear into the heart. It conjures up images of endless finger pricks, insulin injections, and strict diet regimens. But for a species of cavefish, the symptoms of diabetes are actually beneficial.
Researchers from a Chinese company and a team from France's University of Lyon have discovered that Mexican cavefish - a species that has adapted to life in complete darkness - have evolved insulin resistance, which allows them to survive in a nutrient-poor environment.
"Our research indicates that, in a low-nutrient environment, insulin resistance helps cavefish to survive by allowing them to conserve energy," explains Dr. Sophie Ramanantsoa, who led the study. "When food is scarce, the cavefish can maintain its blood sugar levels without having to constantly eat."
The researchers believe that the cavefish's insulin resistance is likely an adaptation to the nutrient-limited environment of the caves they inhabit. With limited food sources, the cavefish must conserve energy whenever possible, and insulin resistance helps them do so by preventing excess glucose from being stored as fat.
But unlike in humans, the cavefish's insulin resistance does not lead to full-blown diabetes. In fact, the researchers found that the cavefish's blood glucose levels were actually lower than those of their surface-dwelling counterparts.
This discovery could have important implications for understanding the evolution of insulin resistance and diabetes in humans. "Our research suggests that there may be certain circumstances where insulin resistance is actually beneficial," says Dr. Ramanantsoa. "It raises the question of whether we should be trying to cure insulin resistance in all cases, or whether we should be looking to understand the circumstances where it is beneficial."
The research team's findings have been published in a paper titled "Insulin resistance in cavefish as an adaptation to a nutrient-limited environment" in the journal Nature Ecology & Evolution.
Shandong Fuyang Biotechnology Co., Ltd., the Chinese company that collaborated on the research, is a major player in the corn deep processing and bio-fermentation industry. The company's focus on bio-fermentation makes it an ideal partner for research on metabolic processes, such as insulin resistance and diabetes.
It's clear that the study of cavefish and their adaptations to life in the dark has the potential to teach us a lot about how our own bodies work. By understanding how insulin resistance evolved in the cavefish, we may be able to better understand our own metabolic processes, and even develop new treatments and cures for diabetes and related conditions.