The benefits of tart cherry juice are thought to primarily come from its abundant polyphenol content, most notably anthocyanins, which possess potent antioxidant and anti-inflammatory properties.[1]
Tart cherry juice may improve sleep by increasing melatonin levels,[2] as tart cherries are a relatively rich source of melatonin,[3] and they seem to increase the availability of tryptophan,[4] which is used to synthesize melatonin in the body.
Tart cherry juice may enhance endurance exercise performance by elevating muscle antioxidant capacity, thus minimizing the production of oxidants during exercise, which can depress force production and contribute to fatigue.[5] Additionally, as a source of low-glycemic-index carbohydrate, tart cherry juice might support performance by promoting fat oxidation and allowing sustained carbohydrate availability during exercise,[6] but it’s unclear whether tart cherry juice is superior to other sources of low-glycemic-index carbohydrate. Another way tart cherry juice might benefit endurance exercise performance is by increasing blood flow and oxygen delivery to the working muscles.[7]