Why cherries can be a smart summer fruit for blood sugar, mood, and sleep

Dr. Maya Rozman, scientific adviser to the Plant Council, says cherries are not just tasty but may be a particularly smart choice for people with diabetes or prediabetes. Although they contain about 12% sugar, their glycemic index is very low, around 20 to 22, far below watermelon and lower than apples. That means they raise blood sugar more slowly and are less likely to trigger sharp spikes, especially in type 2 diabetes or prediabetes.

Rozman says cherries are rich in anthocyanins, powerful antioxidants linked in studies to better insulin sensitivity, less inflammation, and healthier pancreatic function. The same compounds may also lower cardiovascular risk by reducing inflammation in artery walls, preventing oxidation of LDL cholesterol, and improving blood-vessel flexibility. She notes that some studies have found these effects stronger than those seen with red wine, without alcohol or extra calories.

She also highlights a possible sleep benefit, especially from sour cherries, which contain natural melatonin and polyphenols that have been examined in small studies on sleep quality, sleep duration, and sleep efficiency. Most of that research used sour cherry juice, not regular sweet cherries, and the tested doses were not always comparable to an ordinary snack portion.

Rozman says fresh cherries, or frozen cherries without added sugar, are preferable to juice, dried cherries, or canned cherries in syrup. Processing removes much of the balancing effect and can sharply increase sugar levels. She also notes that whole cherries are more filling because they contain water, fiber, and volume. At about 60 calories per 100 grams, she suggests a snack portion of 200 grams, roughly enough for a midafternoon snack, though the exact number depends on cherry size.