Established for the first time in mice.
Copper does a lot more for humans than providing a malleable and conductive metal for cookware, electronics, jewelry, and plumbing. It’s been known to play a role in the formation of red blood cells, iron absorption, developing connective tissue, and supporting the immune system, according to a new press release on the material.
Now, a new study, published in Nature Chemical Biology, has established yet another important role of copper for the first time — metabolizing fat.
"We find that copper is essential for breaking down fat cells so that they can be used for energy," study lead Chris Chang, professor of chemistry at UC Berkeley, said in a press release. "It acts as a regulator. The more copper there is, the more the fat is broken down.”
Using mice with a genetic mutation that causes a buildup of copper in the liver, the researchers were able to make the link between copper and its fat-metabolizing abilities.
Notably, these mice have larger deposits of fat than the average mouse, and the inherited condition, Wilson’s disease, also occurs in humans. Analysis of the mice with Wilson’s disease revealed that these mice had lower levels of copper in their fat tissues compared to the control mice.
The researchers then treated the Wilson’s disease mice with isoproterenol, which is a beta agonist (medication that relaxes muscles of the airways) known to induce the breakdown of fat into its building blocks, fatty acids. Compared to the control mice, the mice with Wilson’s disease displayed less fat-breakdown activity.
These results inspired the researchers to clarify the mechanism by which copper influences the breakdown of fat by conducting cell culture analyses. They found that copper binds to phosphodiesterase 3 (PDE3), which is an enzyme that binds to cAMP (an important messenger in many biological processes), halting the messenger’s ability to promote the breakdown of fat.
"When copper binds phosphodiesterase, it's like a brake on a brake," said Chang.
According to the Food and Nutrition Board of the Institute of Medicine, the average estimated dietary requirement for copper is about 900 micrograms per day (for adults). The Board also found that only about 25 percent of the US population gets enough copper daily.
Foods like leafy greens, mushrooms, seeds, nuts, beans, oysters and other shellfish are packed full of copper, according to the press release, and Chang says copper could potentially play a role in “restoring a natural way to burn fat.”
But importantly, since the study was conducted with mice, we can’t yet confirm whether copper has the same fat-burning effects on humans.
Still, as Chang explains, "Copper is not something the body can make, so we need to get it through our diet.”