May protect against diabetes and lower blood sugar levels

Grapes include 23 grams of sugar per cup (151 grams), making you question if they're a smart choice for diabetics. If you look at their glycemic index (GI) rating — a measure of how rapidly a meal boosts your blood sugar — it ranges from 49 to 59, depending on the grape type. Similarly, the definition of low GI varies depending on the source – some people regardless of 55 are low, while others consider less than 50 to be poor.

This indicates that grapes' GI scores can range from low to medium, implying that they can boost your blood sugar levels slowly or moderately but will not necessarily spike them. Keep in mind, however, that eating too much of a low GI item will have the same impact on blood sugars as eating too much of a high GI food. As a result, it's better to consume grapes in moderation. Furthermore, chemicals identified in grapes may aid enhance insulin response indicators. Grapes and grape supplements significantly reduced homeostatic model assessment of insulin resistance (HOMA-IR), a marker of insulin resistance, in a review of 29 trials involving 1,297 individuals.