Blueberries vs Grapes: Which Fruit Is Better for Blood Sugar?

Reviewed by Dietitian Mandy Enright, M.S., RDN, RYT

Key Points

• Fruit contains sugar, but not all sugars found in fruit can impact blood sugar the same way.

• Blueberries have less carbs and more fiber than grapes, plus anthocyanins for blood sugar control.

• Pairing fruit with protein, fat and other fiber sources can help keep blood sugars more stable.

Blood sugar refers to the amount of glucose, or sugar, in the blood at any given time. “We need glucose to fuel our brain, muscles and other organs, but consistently elevated blood sugar over time can increase the risk of complications, particularly for people with diabetes,” says Caroline Thomason Bunn, RD, CDCES, a dietitian and diabetes educator. Big blood sugar swings throughout the day can also negatively impact energy, mood and metabolic health.

Fruit often gets a bad rap since it contains sugar in the form of fructose, but not all foods with sugar impact blood sugar in the same way. “The fiber in whole fruit helps slow digestion and can lead to a more gradual rise in blood sugar compared with foods that contain added sugars and little fiber,” says Bunn. Fruit also contains antioxidants that have been shown to support healthy blood sugar levels.

Grapes and blueberries are two popular fruits, and you may be wondering which is better for blood sugar. We asked dietitians how each of these fruits influences blood sugar levels, along with blood-sugar-friendly ways to enjoy them.

Blueberries and Blood Sugar

“Blueberries contain carbohydrates and natural sugar, so they will cause some increase in blood sugar,” says Bunn. However, they also contain fiber and are relatively low in total carbohydrates for a serving of fruit. One cup of blueberries has 84 calories, 22 grams of total carbohydrates, 15 grams of sugar and 4 grams of fiber. Fiber slows how fast food leaves your stomach, how quickly carbs are broken down and how fast glucose is absorbed in the bloodstream. Since blueberries have fiber, they won’t spike your blood sugar as much as drinking fruit juice, which often lacks in fiber.

Research shows that blueberries, and other berries, boast benefits for glucose regulation, says registered dietitian and diabetes educator, Vandana Sheth, RDN, CDCES, FAND. “A systematic review and meta-analysis found improvements in fasting blood glucose and A1C among those with diabetes consuming blueberries or cranberries,” she says. Some of the blood-sugar benefits of blueberries seem to come from a group of plant compounds called anthocyanins. Anthocyanins are potent antioxidants that give blueberries their dark blue hue. Along with fighting inflammation and oxidative stress, research shows that anthocyanins play a role in the breakdown of carbohydrates, specifically reducing the amount of glucose that’s released into the bloodstream.

Grapes and Blood Sugar

Grapes are higher in sugar and lower in fiber compared to blueberries. One cup of grapes has 125 calories, 29 grams of total carbohydrates, 25 grams of sugar, and 1.4 grams of fiber. So, if you’re comparing eating one cup of grapes to one cup of blueberries, the grapes will lead to a sharper rise in blood sugar. “That said, grapes are still a nutritious whole fruit. They provide fiber, water, vitamins and beneficial plant compounds, and there’s no need to avoid them simply because they contain natural sugar,” says Bunn. Rather, it’s about pairing them with other foods high in fiber, protein and/or fat to blunt the blood sugar spike.

Similar to blueberries, red and purple grapes contain anthocyanins, and all grape skins contain some resveratrol, another potent plant compound. “Research on grape products and grapes has shown some potential benefits for insulin resistance. However, fasting glucose and A1C have been mixed. Much of the research has focused on grape products rather than fresh grapes,” says Sheth. Still, grapes can be enjoyed and fit into a blood-sugar-friendly diet, she says.

Which is Better for Blood Sugar?

When it comes to balanced blood sugar levels, dietitians say blueberries have an edge. “They provide slightly more fiber and somewhat fewer carbohydrates than grapes. Plus, we have more research examining berries and glucose regulation,” says Sheth. That doesn’t mean grapes are a “bad” choice or should be avoided. “The difference between these two fruits is relatively small compared with the overall meal, portion and what else you’re eating,” says Bunn.

Ultimately, says Bunn, most Americans fall short on their fruit servings for the day. And research shows that eating fruit may be protective against type 2 diabetes. Further, those who eat 1.5 to 2 cups of fruit per day are at a lower risk of dying from chronic diseases. “The key is portion size, what you pair your fruit with and your individual glucose response,” says Sheth.

How to Enjoy Blueberries and Grapes for Better Blood Sugar

Pairing protein, fiber and fat together helps keep blood sugar levels steady. Here’s how to enjoy both blueberries and grapes for better blood sugar.

• Add to Greek yogurt. For breakfast or a snack, add blueberries to strained (Greek-style) yogurt, which is rich in protein. “Pairing carbohydrate-containing fruit with protein, fat and/or fiber can help make a snack more satisfying and can result in a more gradual blood sugar rise,” says Bunn. For more protein, fiber and fat, add nuts or chia seeds.

• Pair with protein and fat for a balanced snack. Enjoy grapes with some cheese or a handful of nuts for a balanced snack or appetizer, says Sheth. Both cheese and nuts contain protein and fat, which together work to slow the rise of blood sugar.

• Mix into a smoothie. Blend blueberries or grapes into a smoothie with strained (Greek-style) yogurt or protein powder, milk and a tablespoon of almond butter for a balanced meal or snack you can take on-the-go.

• Add to your lunch. Portion out a one-cup serving of blueberries or grapes to have with your lunch. Just make sure your lunch has a protein source to make the pairing blood-sugar-friendly. Or add some sweetness to your lunch by adding some blueberries to a salad or grapes into chicken salad.

Our Expert Take

While blueberries and grapes both contain sugar, they also have fiber, which slows the rise of blood sugar. Dietitians say blueberries have a slight edge over grapes when it comes to supporting healthy blood sugar levels since they have fewer total carbohydrates and more fiber, as well as potent anthocyanins that favorably impact glucose regulation. But all fruits, including grapes, can be part of a balanced diet, even if you have high blood sugar or diabetes. It’s about pairing fruit with protein, fiber and healthy fats to slow the rise of blood sugar and release of insulin. This combination will also keep you feeling more full for longer and give you steady energy throughout the day.

Read the original article on EatingWell