Blueberries are small blue fruits in the berry family and come from a flowering bush (Vaccinium sect. Cyanococcus) closely related to cranberries and huckleberries. Sweet and tart, these little fruits appear green and deepen to a purple and blue hue as they ripen. They can be eaten raw, purchased frozen, or utilized in recipes.
This article will explore how blueberries may impact blood sugar levels and the health benefits of including this fruit in your diet.
Wild blueberries are considered a low glycemic index fruit, with a score of 53. This score is on the upper end of the low GI rating and higher than oranges (45), strawberries (40), and peaches (28).¹ However, the low glycemic index rating means consuming blueberries should not cause dramatic rises or spikes in blood sugar levels.
While fresh fruit is always the best option, many consume blueberries in jams and jellies, which can contain added sugars. These add-ins can dramatically increase the glycemic index of the product, and people living with chronic conditions like diabetes should be mindful of consumption.
Review the nutrition label to determine if other ingredients have been added when selecting a product that may include this delicious berry.
The below glycemic index and glycemic load data is for 100g of raw, wild blueberries, which is approximately one cup of blueberries:¹ ²
Blueberries contain many nutrients and minerals, including copper, beta-carotene, folate, choline, vitamins A and E, and manganese. This fruit is one of the most nutrient-dense berries and contains 85% water.
The nutritional information below is for 100g of raw, wild blueberries.²
A (3 µg), B6 (0.05 mg), C (8.1 mg).
Blueberries are often included in diets aimed at weight loss. One of the main reasons for their inclusion is that this little berry contains antioxidants, fiber, and phytochemicals that will keep you full and ensure your blood sugar levels remain in an optimal zone.
One animal study found that rats consuming blueberries for 90 days lost more belly fat than the group who did not consume blueberries.³⁰ Researchers believe this study shows a link between the antioxidants found in blueberries and the body's metabolism of fat and glucose.
Blueberries are also known to aid in the recovery of athletes. These mighty berries help fight inflammation and, if consumed before a strenuous workout, can allow athletes to move forward and have less oxidative stress, leading to less fatigue and pain.³¹
If you are ready to add blueberries to your meal plan, try one of the below options to start reaping all of the health benefits of this delicious fruit:
With a low glycemic index rating, blueberries are a safe choice for people living with diabetes. While blueberries contain a moderate amount of sugar, the bioactive compounds in blueberries outweigh any negative impacts of this sugar content.
Research suggests that anthocyanins (the main antioxidant found in blueberries) have beneficial effects on insulin sensitivity and glucose metabolism. These impacts have been observed in consuming fresh and freeze-dried blueberries.²⁴ ²⁵ ²⁶
In a study involving 32 obese participants with insulin resistance, consuming two blueberry smoothies a day caused major improvements in insulin sensitivity.²⁷ Improved insulin sensitivity could lower the risk of metabolic syndrome and type 2 diabetes.²⁸
Another study published in 2022 involved 34 women with a history of gestational diabetes. Those who ate two cups of blueberries as a snack and a fiber supplement were found to be less likely to gain excessive weight and had lower blood sugar levels after 18 weeks.²⁹
Symptoms of a blueberry allergy include itchiness of the mouth, lips, or throat, swelling, and redness. In severe cases, allergic reactions can cause hives, difficulty breathing, and anaphylaxis. Please consult a healthcare professional if you suspect an allergy, sensitivity, or intolerance to blueberries.
Outside of an allergic reaction, blueberries can possibly interact with certain medications, especially blood thinners like warfarin, due to the berry’s high vitamin K content. If you are concerned about a possible blueberry interaction, please consult your healthcare provider.
Blueberries also contain oxalates, natural compounds that can contribute to kidney stone formation. If you have a history of kidney stones, it is recommended to consult with your doctor and moderate blueberry consumption.
The glycemic index (GI) is a measure of how quickly a carbohydrate-containing food raises blood sugar levels compared to a reference food, usually glucose. It ranks foods on a scale from 0 to 100, with higher values indicating a faster rise in blood sugar. The glycemic index (GI) scale is typically categorized as follows: Low GI [55 or less], Medium GI [56-69], High GI [70 or higher]. Foods with a high glycemic index digest rapidly and can cause dramatic fluctuations in blood glucose or glucose spikes.
Glycemic load (GL) takes into account both the quality (glycemic index) and quantity (carbohydrate content) of carbohydrates in a specific serving of food. It is a measure of how much a particular food will raise blood sugar levels. GL is calculated by multiplying the glycemic index of a food by its carbohydrate content and dividing it by 100. It provides a more accurate representation of the overall impact of a food on blood sugar compared to the glycemic index alone.
There is some evidence to suggest that blueberries may have a positive effect on insulin sensitivity and glucose metabolism. However, more research is needed to fully understand the mechanisms behind this potential benefit and to determine the extent of its impact. It is important to note that while blueberries may have health benefits, they should not be relied upon as a sole treatment for any medical condition. It is always best to consult with a healthcare professional for personalized advice and treatment.
Yes, blueberries are considered low glycemic due to their low glycemic index (GI) score of 53. This means they have a minimal impact on blood sugar levels.
Yes, people living with diabetes can eat blueberries as they are low in glycemic index and high in fiber and antioxidants. However, they should consume them in moderation and as part of a balanced diet.