Apple peels contain phlorizin, which can reduce plasma glucose levels in a manner similar to that of inhibitors for sodium-glucose cotransporters.
In this study, we examined the influence of a peeled apple, a sodium-glucose cotransporter-2 inhibitor (ipragliflozin) in combination with a peeled apple, and an unpeeled apple on interstitial glucose in a healthy individual across 3 experiments.
For Experiments 1, 2, and 3, the healthy volunteer consumed 327 g peeled Sun Fuji apple, took 50 mg ipragliflozin, and then consumed 327 g peeled Sun Fuji apple, or consumed 370 g unpeeled Sun Fuji apple (peel weight was 43 g), respectively. In each condition, the apple was eaten within a 15-minute period and interstitial glucose levels were measured every 15 minutes for 11.5 hours using FreeStyle Libre (Abbott Laboratories, Abbott Park, Illinois).