Everything You Need to Know About Blueberries — One of the Most Antioxidant-Rich Foods

Blueberries pack big nutritional benefits into a small package. These powerhouse berries evoke the flavor of summer but deserve a place in your diet all year long.

You may find yourself more likely to eat blueberries than other fruits because they're easy to prepare — there's no need for peeling or slicing (just a rinse under water). This type of accessibility plays an important role in helping you maintain a healthy diet, because you're more likely to eat quick and easy-to-prep nutritious foods.

What's more, blueberries provide a rich blend of nutrients that may benefit your heart health, regulate blood sugar, improve your skin and preserve cognitive function. Their abundance of antioxidants and fiber may play a role in preventing a number of diseases, which is why the blueberry is a flavorful, accessible part of a healthy diet.

One cup of fresh blueberries is equal to a single serving. One cup of blueberries contains:

• ‌Calories‌: 84
• ‌Total fat‌: 0.5 g
• ‌Cholesterol‌: 0 mg
• ‌Sodium‌: 1.5 mg
• ‌Total carbs‌: 21.4 g
• ‌Dietary fiber‌: 3.6 g
• ‌Sugar‌: 14.7 g
• ‌Added sugar‌: 0 g
• ‌Protein‌: 1.1 g

• ‌Total fat‌: One cup of blueberries has 0.5 grams of total fat, which includes 0.2 grams of polyunsaturated fat, 0.07 grams of monounsaturated fat, 0 grams of saturated fat and 0 grams of trans fat.
• ‌Carbohydrates‌: One cup of blueberries has 21.4 grams of carbs, which includes 3.6 grams of fiber and 14.7 grams of naturally occurring sugars.
• ‌Protein‌: One cup of blueberries has 1.1 grams of protein.

• ‌Vitamin K‌: 24% of your Daily Value (DV)
• ‌Manganese‌: 22% DV
• ‌Vitamin C‌: 16% DV
• ‌Copper:‌ 9% DV
• ‌Vitamin E:‌ 6% DV
• One cup of blueberries is not a significant source of ‌potassium‌ (2% DV), ‌calcium‌ (1% DV) or ‌phosphorus‌ (1% DV).

Blueberries are part of a healthy diet and can benefit your heart, skin, brain and blood glucose levels. They are filled with potent antioxidants that may lower your risk of disease and are also a good source of fiber and other important nutrients like vitamin C.

‌1. Blueberries Are Linked to Better Heart Health‌

Many of the health benefits blueberries provide — including their heart-health benefits — can be attributed, at least partially, to their phytonutrients, plant compounds that have antioxidant effects. One large class of phytonutrients are flavonoids, which include anthocyanins. These are protective compounds that give blueberries their rich blue hue.

One cup of blueberries per day improved heart function and arterial stiffness and was predicted to contribute to a 12 to 15 percent lower risk of heart disease in people with overweight and obesity (aged 50 to 75) with metabolic syndrome in a May 2019 study published in ‌The American Journal of Clinical Nutrition‌.

It's important to note that this study was supported by the U.S. Highbush Blueberry Council, but it's still significant because it examined the effect of blueberry intake over six months — longer than other trials of its type to date. The protective effect may be due to the anthocyanins in blueberries, per the researchers.

"Phytonutrients like anthocyanins are defenders of health, and may help reduce the risk of chronic disease like heart disease," says Mary Opfer, RD, a clinical assistant professor of nutrition at Pace University.

The fiber in blueberries may also contribute to heart health. Blueberries contain 3.6 grams of fiber per serving, or 14 percent of your daily value, and are certified as heart-healthy by the American Heart Association.

Certified foods must be a good source (provide at least 10 percent of the daily value per serving size) of one or more of these six nutrients: vitamin A, vitamin C, iron, calcium, protein and dietary fiber. Blueberries qualify due to their fiber content.

"A diet higher in fiber is associated with lower cardiovascular risk, and in general, we know that diets higher in antioxidant-rich fruits and vegetables like blueberries tend to be associated with a lower risk of inflammation and chronic disease," says Mary Ellen Phipps, RDN, a spokesperson for the U.S. Highbush Blueberry Council.

‌2. They Can Benefit Your Skin‌

A number of the antioxidants in blueberries can help protect your skin from oxidative damage that accelerates the aging process. "Blueberries have many essential nutrients for skin health, with the main player being vitamin C," Opfer says.

Vitamin C supports the production of collagen, a structural protein that gives skin its elasticity. With age, the vitamin C content in your skin and your body's production of collagen naturally declines, per Oregon State University.

This decline in collagen can contribute to wrinkles and also cause health issues like weakening muscles or osteoarthritis due to worn cartilage, according to the Cleveland Clinic.

Other than aging, too little collagen in the body is most often caused by a poor diet. Blueberries also provide copper and zinc, two additional nutrients required for collagen production.

‌3. Blueberries Are a Brain-Healthy Food‌

Blueberries are specifically noted in the MIND Diet (Mediterranean-DASH Intervention for Neurodegenerative Delay), an eating plan based on results of over 20 years of data from the Chicago Health and Aging Project (CHAP) aimed to help lower the risk of brain health decline and developing Alzheimer's disease.

The MIND diet encourages two or more servings of berries per week and specifies that blueberries may be particularly beneficial, per the Academy of Nutrition and Dietetics.

"The phytonutrients in blueberries may help with cognitive health and brain function by protecting the brain cells from stress and inflammation," Opfer says.

Greater dietary intakes of blueberries and strawberries were associated with slower rates of cognitive decline in older women in a July 2012 study published in the ‌Annals of Neurology‌, an effect researchers owe to the flavonoids in berries. This study was partially funded by the California Strawberry Commission but is notable because it reviewed data of more than 16,000 participants from the Nurses' Health Study.

Eating the most blueberries and strawberries was linked to delaying memory decline by up to 2.5 years. The study researchers note that berry-derived anthocyanidins, flavonoids that are counterparts of anthocyanin, are uniquely able to cross the blood-brain barrier to accumulate in areas of the brain responsible for learning and memory such as the hippocampus.

In general, flavonoids have powerful protective effects against oxidative stress and inflammation, which are thought to contribute to cognitive impairment.

‌4. They Might Benefit Blood Glucose Levels‌

Blueberries are a fantastic way to enjoy sweetness without over-consuming calories. "Blueberries don't have a lot of sugar, but they do have a lot of flavor," Opfer says.

The glycemic index measures the impact of foods with carbohydrates on blood sugar levels, and foods with a low GI number (considered 55 or less) can raise blood glucose levels more slowly than those with a medium or high GI number. Blueberries have a glycemic index of 53, which is considered low.

Eating foods less likely to cause large increases in blood sugar levels may help you lose weight or maintain a healthy weight, eat healthier meals and maintain blood sugar levels as part of a diabetes plan, per the Mayo Clinic.

Eating certain whole fruits — particularly blueberries — was significantly associated with a lower risk of developing type 2 diabetes in an August 2013 study published in the ‌British Medical Journal‌‌.‌ The researchers observed the diets of more than 187,000 participants and noted the beneficial effects could be due to fiber, antioxidants and phytochemicals.

That said, while whole fruit is generally considered part of a healthy diet that may reduce type 2 diabetes risk, the results of this study should be treated with caution: It used surveys to ask participants how often they ate a particular type of food, which can be a less reliable way of gathering dietary information than other methods.

A December 2016 review published in the journal ‌Antioxidants‌ noted that while current evidence of blueberries' effect on insulin resistance and glucose intolerance is promising, more long-termed, randomized and placebo-controlled trials are needed to determine the role of blueberries in preventing or delaying type 2 diabetes.

‌Allergies‌

A food allergy is an immune system reaction from a certain food that can cause symptoms such as hives, swollen airways or even life-threatening anaphylaxis. It affects up to 3 percent of adults, per the Mayo Clinic.

While blueberry allergy is rare, it has been reported and can cause anaphylaxis like other food allergies. Speak to an allergist to determine your risk: If you have a food allergy, you may need to carry epinephrine with you at all times in case of a severe reaction.

‌Drug Interactions‌

There are currently no known drug interactions. Be sure to discuss any medication and food interactions with your health professional.

You can typically find fresh or frozen blueberries in supermarkets year-round, but they're in season from late spring to the end of summer in North America. Follow these tips to purchase, wash and store blueberries.

‌Check the package.‌ Look for firm, full-colored berries that aren't bruised or oozing. Be sure to flip the container to check the berries at the bottom and ensure they're free of mold, per Iowa State University.

‌Store in the refrigerator.‌ Cover and refrigerate berries when you get home. It's best to hold off on washing your berries until you're ready to use them so they stay fresh for several days, per the university.

‌Wash properly.‌ Even if you buy organic berries, it's important to wash all produce before eating it. Produce can become contaminated in a number of ways before it reaches your plate, including by animals, harmful substances in the soil and water or by poor hygiene from handlers. Produce passes through many hands after it is harvested, which increases contamination risk, according to the U.S. Food & Drug Administration.

Wash your hands for 20 seconds with warm water and soap before and after handling fresh produce. Gently rub the berries while holding them under plain running water (no need to use soap or produce wash) and then dry them with a clean cloth or paper towel to further remove lingering bacteria.