Antioxidants in Turmeric: The Curry Spice Made Mice Better at Exercising

Turmeric, the bright, fragrant spice that turns curries yellow, is developing a reputation outside of the kitchen as a nutritional supplement. It’s the subject of clinical trials, countless studies that are all narrowing down on the same conclusion: Aside from making curry taste good, turmeric probably has some powerful anti-inflammatory effects.

A paper published November 21 in The Journal of Applied Physiology looked specifically at curcumin — the active component in turmeric that has been the focus of several rounds of clinical trials, all of which have demonstrated that it likely has a series of anti-inflammatory effects. Senior author Lie Gao, M.D., Ph.D., an assistant professor at the University of Nebraska College of Medicine who specializes in cardiac physiology, explains that his team was primarily interested in turmeric for it’s potential to increase exercise capacity — a common problem for people who suffer from heart failure. His experiment on mice found that dosing with curcumin for 12 weeks was enough to help mice with heart failure increase their ability to exercise — but it also increased the exercise capacity of perfectly healthy mice.

At the outset of Gao’s experiment, the mice who had induced heart failure, unsurprisingly, struggled to complete a treadmill running task. But over the course of eight weeks, he noticed that the mice were able to run farther and slightly faster than a control group that didn’t receive turmeric. He noticed the same pattern in healthy mice who were also treated with turmeric: They increased their running capacity — so they were able to go for longer — and their running speed.

When Gao looked more closely at how curcumin was affecting these mice’s hearts, he found no effect at all. Puzzling, since this was supposed to be an experiment on treatments for heart failure. Instead, when he turned to their skeletal muscles, he found a mechanism that might be responsible.

Gao’s findings build upon a series of findings from other labs, suggesting that turmeric can help the body fend off oxidative stress — which is essentially the creation of rogue electrons that can wreak havoc on the body. Gao’s study took a deep look into how turmeric might be able to do this: by increasing the production of a protein called Nrf2, which helps the body combat free radicals. In both the healthy mice and the mice with heart failure, he noticed the same thing. Curcumin seemed to help the body produce a protein that set a cascade of antioxidant effects into motion.

“Curcumin upregulated a protein, called Nrf2 in skeletal muscle, resulting in an increase in a battery of antioxidant enzymes and enhancement of antioxidant defense,” Gao told Inverse. “Our data showed that Curcumin upregulates Nrf2 in both normal and heart failure skeletal muscles, suggesting a same mechanism takes effect in both conditions.”

While this finding will likely have implications for healthy mice, Gao is more interested in looking into curcumin as a potential therapy for people who suffer from heart failure, which he’ll be looking into in the future.