Blackberry Glycemic Index

Blackberries have a low glycemic index estimated at 25 to 40, depending on ripeness and variety. This places them among the lowest-GI fruits available. Their glycemic load for a one-cup serving is only about 4, which is very low. The range reflects real variation across sources, but all estimates confirm blackberries as a low-GI food.

Yes, blackberries are considered one of the best fruit choices for people with diabetes. They are low in sugar (only 7 g per cup), high in fiber (nearly 8 g per cup), and have a very low glycemic load. Their net carb count of about 6 g per cup makes them easy to fit into most meal plans. As always, this is general nutrition information — individuals should discuss their diet with their healthcare team.

Blackberries have a GI similar to strawberries (about 40) and raspberries (about 30–40), and slightly lower than blueberries (about 53). All berries are low-GI fruits, but blackberries and raspberries have the advantage of higher fiber content per cup, which gives them an especially low net carb count. Blueberries are still a good choice but have a bit more sugar.

Yes, blackberries are keto-friendly in moderation. With only about 6 g of net carbs per cup, they fit easily into strict keto (under 20–30 g net carbs/day) and moderate low-carb diets. A half-cup serving provides just 3 g net carbs, making blackberries one of the lowest-carb fruits available. They are a popular choice for keto dieters who want fruit without exceeding their carb limit.

The deep purple-black color of blackberries comes from anthocyanins, which are antioxidant compounds that may have beneficial effects on insulin sensitivity and blood sugar regulation. While the color itself doesn't directly lower GI, the anthocyanin content is associated with metabolic benefits in some research. Riper, darker blackberries may have slightly more sugar but also more antioxidants.