A quick primer: Mitochondria are the powerhouses of the cells, meaning they help power up the energy that allows all the cells in your body to function optimally. But like most good things, mitochondria deplete with age—that’s why many experts recommend optimizing its function as you grow older, through nutrient-dense foods, fasting, exercise, and supplements. (Check out our full explainer on mitochondrial health here). 

As for where melatonin comes in, “mitochondria will actually manufacture melatonin,” Gundry says, and research shows melatonin also has a protective effect, able to help maintain mitochondrial function. “Melatonin reduces mitochondrial fission and increases their fusion, thereby preserving their normal function,” the report reads. Needless to say, melatonin’s benefits extend way beyond a good night’s rest. 

https://www.mindbodygreen.com/articles/why-you-need-melatonin-in-your-diet-mds-go-to-sources