Fat is not all that bad. Scientists have now discovered a new class of molecules -produced in human and mouse fat – that protects against diabetes.

The researchers found that giving this new “good” fat or lipid to mice with the equivalent of type 2 diabetes lowered their elevated blood sugar.

The team also found that levels of the new lipids called called fatty acid hydroxy fatty acids (FAHFAs) are low in humans with a high risk for diabetes, suggesting that the lipids could potentially be utilised as a therapy for metabolic disorders.

“We can add FAHFAs to the small list of beneficial lipids. These lipids can also reduce inflammation, suggesting that we might discover therapeutic opportunities for these molecules in inflammatory diseases such as Crohn’s disease, rheumatoid arthritis and diabetes,” explained Alan Saghatelian, professor at the Salk Institute and Beth Israel Deaconess Medical Center (BIDMC) in Boston.

FAHFAs had not been noticed previously in cells and tissues because they are present in low concentrations, making them difficult to detect.

Once researchers identified FAHFAs as being the lipid that was different between normal mice and these diabetes-resistant mice, they found that when the mice eat FAHFAs, blood sugar levels dropped and insulin levels rose, indicating the potential therapeutic value of FAHFAs.

To determine whether FAHFAs are also relevant in humans, the team measured FAHFA levels in humans who are insulin-resistant and found that their FAHFA levels were lower in fat and blood, suggesting that changes in FAHFA levels may contribute to diabetes.

“This work suggests that changes in FAHFA levels are a new mechanism in diabetes,” Saghatelian concluded.

The study appeared in the journal Cell.