Blueberries are fruits of a shrub belonging to the heath family. Other members include the cranberry, bilberry, azalea, mountain laurel and rhododendron. There are more than 30 different species of blueberry. Popular varieties include Highbush, Lowbush and Evergreen.
Blueberries grow in clusters and range in size from that of a small pea to a marble. Although all blueberries are “blue” they cover a spectrum of shades from a medium gray-blue to a deep purple-black. All blueberries have a white-gray waxy casing that serves as a protective coat. This silvery sheen is referred to as a “bloom”. The flesh of blueberries is semi-transparent with tiny edible seeds.
Cultivated blueberries are called Highbush and are most commonly seen in the produce section of your grocery store. Lowbush, or wild blueberries, are significantly smaller than their cultivated counterparts. Highbush berries tend to be juicy and sweet while the Lowbush variety is firm with a tangier taste.
Blueberries are one of three fruits indigenous to North America (blueberries, cranberries, Concord grapes). By the time European settlers arrived in the United States, Native American tribes had been using clever preservation techniques for centuries and enjoying blueberries year round. According to legend, the Native Americans offered blueberries to the pilgrims, helping them to make it through their first winter. Because of their tart flavor, wild blueberries did not become popular among colonists until the mid 19th century when sugar became more widely available.
Blueberry cultivation began at the beginning of the 20th century when this fruit became commercially available in 1916. Today, North America accounts for nearly 90% of world blueberry production. Due to its acidic soil, blueberries flourish in Maine and this state accounts for virtually all of this country’s wild blueberry production.
At only 84 calories per cup, blueberries are the perfect summer treat. A good source of both soluble and insoluble fiber, blueberries contain 4 grams of fiber per cup.
These little berries are also a great source of vitamins C and K. With 14.4 mg of vitamin C, a cup of blueberries contains 24% of your suggested daily intake. That same serving of blueberries contains 28.6 mcg of vitamin K, or 36% of the suggested daily intake. Blueberries are an excellent source of the mineral manganese, boasting 25% of the suggested daily intake.
Blueberries are potent little powerhouses with several key health benefits. Perhaps the most well-known of these benefits comes from their high anthocyanidin content. This phytochemical is what gives blue, red and purple fruits and vegetables their color and is best known for its antioxidant activity. Like other dark colored berries, blueberries are one of the most potent sources of antioxidants.
Anthocyanidins help to prevent free-radical damage and oxidative stress in the body, slowing the signs of aging and reducing the risk of diseases caused by chronic or silent inflammation. Anthocyanidins improve the integrity of support structures in the veins and vascular system. This phytonutrient enhances the effects of vitamin C, improves capillary integrity and helps stabilize the collagen matrix.
Animal studies have demonstrated that the compounds in blueberries may help to stave off dementia and reduce the effects associated with Alzheimer’s disease.
Blueberries also contain tannins, the same compounds found in cranberries that help to prevent or eliminate urinary tract infections. These phytonutrients reduce the ability of E. coli, the most common cause of UTIs, from adhering to the urinary tract wall.
Blueberries like other berries and pomegranate contains another phytonutrient called ellagic acid. Like anthocyanidins, ellagic acid has powerful antioxidant and anti-inflammatory benefits.
If you’re looking to obtain the health benefits of blueberries, then you should eat them fresh or frozen. Cooking and processing the berries eliminates their phytonutrient content.
According to a “Shopper’s Guide to Pesticides”, a report published by the Environmental Working Group, blueberries are among the 12 foods with the greatest amount of pesticide residue. To avoid the health risk associated with pesticides, buy organic blueberries. For more information, check out our article that reviews the “dirty dozen” and “clean fifteen”.
Selection and Storage
Blueberries are in season mid-April to early October. Peak harvest is in July – National Blueberry Month.
When selecting blueberries, look for firm, uniform, powdery-blue berries with smooth skin. Blueberries do not ripen after they are picked so avoid berries that are reddish in color unless you plan to use for cooking. Avoid berries that appear soft, moldy, or damaged. Shake the container to ensure all berries move freely. Lack of movement may indicate soft or soggy berries. If the container is stained or leaking juice the berries may be crushed or moldy.
Stored in a container in the refrigerator, blueberries will remain fresh for about a week. Because of the protective powdery coating, blueberries tend to last longer than other types of berries. To get the most of out of your blueberries, do not rinse until you are ready to use. Rinsing takes off the powdery coating that protects the berries from degradation.
Due to their low water content, blueberries freeze wonderfully. If you find yourself with leftover berries, spread on a cookie sheet to freeze. Once the berries are frozen transfer to a plastic bag. Blueberries will keep in the freezer for up to a year.
As with most fruits, especially berries, the best way to enjoy their sweet to tart and tangy flavor is serving them fresh. This tiny fruit is easily added to fruit salads, yogurt, oatmeal or cereal. If you’re making a fruit salad, add the berries last and squirt with some lemon juice. This helps prevent the berries from crushing and preserves them longer.
If you’re cooking with blueberries, keep in mind that they tend to change color during cooking. Acids like lemon make the blue in blueberries turn red while an alkaline environment such as batter causes a greenish tint. To limit color streaking, stir frozen blueberries into batter last.
For a red, white and blue summer treat, top off homemade waffles with a mix of blueberries, blackberries, raspberries and strawberries. For a delightful weekday lunch, enjoy Chicken, Endive, and Blueberry Salad with Toasted Pecans. For a fresh and flavorful chutney delicious served warm or chilled, serve Chicken with Blueberry-Ginger Chutney. For an easy decadent dessert, try our Flourless Chocolate Cakes and serve with fresh berries. The berries and dark cocoa are an excellent source of phytonutrients!
Due to processing, baby foods containing berries do not have detectible levels of anthocyanidins. To ensure your baby is getting the powerful health benefits of these little berries, puree your own blueberry baby food.
A single blueberry bush can produce as many as 6,000 blueberries a year.
David H. Rahm, M.D. is the founder and medical director of The Wellness Center, a medical clinic located in Long Beach, CA. Dr. Rahm is also president and medical director of VitaMedica. Dr. Rahm is one of a select group of conventional medical doctors who have education and expertise in functional medicine and nutritional science. Over the past 20 years, Dr. Rahm has published articles in the plastic surgery literature and educated physicians about the importance of good peri-operative nutrition.