Blueberries are perennial flowering plant with blue or purple berries. They are classified in the section Cyanococcus within the genus Vaccinium. Vaccinium also includes Cranberries, bilberries, huckleberries and Madeira blueberries. Commercial blueberries-both wild (lowbush) and cultivated (highbush) – are all native to North America. The high Bush varieties were introduced into Europe during the 1930s.
Blueberries are usually prostrate shrubs that can vary in size from 10 centimeter (3.9 in) to 4 meters (13 ft) in height. In commercial production of blueberries, the species, with small, pea-size berries growing on low-level bushes are known as “lowbush blueberries” (synonymous with “wild”), while the species with large berries growing on taller cultivated bushes are known as “highbush blueberries”. Canada is the is the leading producer of lowbush blueberries, while the United States produces some 40% of the world supply of highbush blueberries.
FAST FACTS ON BLUEBERRIES
Blueberries can be eaten freshly picked or incorporated into a variety of recipes. They can also be purchased frozen.
● blueberries contain a plant compound called anthocyanins. This gives blueberries both their blue color and many of their health benefits.
● Blueberries can help heart health, bone strength, skin health, blood pressure, diabetes management, cancer prevention, and mental health.
● One cup of blueberries provides 24 percent of a person recommended daily allowance of vitamin C.
● Use blueberries to top waffles, pancakes, yogurt, oatmeal, or cereal, blend them in a smoothie or syrup, or fold them into muffins and sweet breads.
● People who use blood-thinners, such as warfarin, should speak to their doctor before increasing their intake of blueberries, as the high vitamin K content can affect blood clotting.
HEALTH BENEFITS OF BLUEBERRIES
A type of flavonoids called anthocyanins gives blueberries many of their health benefits. Flavonoids are plant compounds that often have a powerful antioxidant effect.
Anthocyanin is responsible for the blueberry’s characteristic blue color. It also contributes to the numerous advantages of blueberries.
Consuming a variety of fruits and vegetables has long been associated with a reduced risk of many lifestyle-related health conditions.
Many studies have suggested that increasing consumption of plant foods such as blueberries decreased the risk of obesity, diabetes, heart disease, and overall mortality. Plant foods may also promote hair and skin health, increased energy, and overall lower weight.
Freezing blueberries is often discussed by experts. It is often said that the freezing process can diminish the potency of the blueberry’s health benefits. One study showed that over the course of 6 months in storage, the anthocyanins degraded by 59 percent.
However, this is not confirmed, and different sources takes different stances on whether freezing blueberries reduces their impact on health. When in doubt, buy fresh, organic blueberries.
Although more research is needed, blueberries are strongly linked to various different elements of healthful living.
■ MAINTAINING HEALTHY BONES
Blueberries contain iron, phosphorus, calcium, magnesium, zinc, and vitamin K. Each of these is a component of bone. Adequate intake of these minerals and vitamins contributes to building and maintaining bone structure and strength.
Iron and zinc fulfill crucial roles in maintaining the strength and elasticity of bones and joints.
Low intakes of vitamin K have been linked to a higher risk of bone fracture. However, adequate vitamin K intake improves calcium absorption and may reduce calcium loss.
■ SKIN HEALTH
Collagen is the support system of the skin. It relies on vitamin C as an essential nutrient, and works to help prevent skin damage caused by the sun, pollution, and smoke. Vitamin C may also improve collagen’s ability to smooth wrinkles and enhance overall skin texture.
One cup of blueberries provides 24 percent of the recommended daily allowance of vitamin C.
■ LOWERING BLOOD PRESSURE
Maintaining low sodium levels is essential to keeping blood pressure at a healthful level. Blueberries are free of sodium.
They contain potassium, calcium, and magnesium. Some studies have shown that diets low in these minerals are associated with higher blood pressure. Adequate dietary intake of these minerals is thought to help reduce blood pressure.
However, other studies have counteracted these findings. For a 2015 study of people with metabolic syndrome found that daily blueberry consumption for 6 weeks did not affect blood pressure levels.
■ MANAGING DIABETES
Studies have found that people with type 1 diabetes who consume high-fiber diets have low blood glucose levels, and people with type 2 diabetes who consume the same may have improved blood sugar, lipid, and insulin levels. One cup of blueberries contributes 3.6 grams (g) of fiber.
A large 2013 cohort study published in the BMJ suggested that certain fruits may reduce the risk of type 2 diabetes in adults.
Over the course of the study, 6.5 percent of the participants developed diabetes. However, the researchers found that consuming three servings per week of blueberries, grapes, raisins, apples or pears reduced the risk of type 2 diabetes by 7 percent.
■ PROTECTING AGAINST HEART DISEASE
The fiber, potassium, folate, vitamin C, vitamin B6, and phytonutrients content in blueberries support heart health. The absence of cholesterol from blueberries is also beneficial to the heart. Fiber content helps to reduce the total amount of cholesterol in the blood and decrease the risk of heart disease.
Vitamin B6 and folate prevent the buildup of a compound known as homocysteine. Excessive buildup of homocysteine in the body can damage blood vessels and lead to heart problems.
According to a study from the Harvard School of Public Health and the University of East Anglia, in the United Kingdom (U.K.) regular consumption of anthocyanins can reduce the risk of heart attacks by 32 percent in young and middle-aged women.
The study found that women who consumed at least three servings of blueberries or strawberries per week showed the best results.
■ PREVENTING CANCER
Vitamin C, vitamin A, and the various phytonutrients in blueberries function as powerful antioxidants that may help protect cells against damage from disease-linked free radicals.
Research suggests that antioxidants may inhibit tumor growth, decrease inflammation in the body, and help ward off or slow down esophageal, lung, mouth, pharynx, endometrial, pancreatic, prostate, and colon cancers.
Blueberries also contain folate, which plays a role in DNA synthesis and repair. This can prevent the formation of cancer cells due to mutations in the DNA.
■ IMPROVING MENTAL HEALTH
Population-based studies have shown that consumption of blueberries is connected to slower cognitive decline in older women.
Studies have also found that in addition to reducing the risk of cognitive damage, blueberries can also improve a person’s short-term memory and motor coordination.
■ HEALTHY DIGESTION, WEIGHT LOSS, AND FEELING FULL
Blueberries help to prevent constipation and maintain regularity for a healthful digestive tract because of their fiber content.
Dietary fiber is also commonly recognized as an important factor in weight loss and weight management by functioning as a “bulking agent” in the digestive system. High fiber foods increase satiety, or the feeling of being full, and reduce appetite.
One Cup of Fresh Blueberries
That Same Serving per 100 g Provides:
Blueberries also contain copper, beta-carotene, folate, choline, vitamin A, and E, and manganese.
As well as anthocyanins, vitamins, and minerals, blueberries contain a diverse range of phenolic compounds such as quercetin, kaempferol, myricetin, and Chlorogenic acid. These contribute to the antioxidant capacity of blueberries.
The large quantities of bioactive compounds place blueberries high on the Aggregates Nutrient Density Index (ANDI). This index rates food based on their vitamin and mineral content, phytochemicals composition, and antioxidant capacity.
Foods with the most nutrients per calorie have the highest rankings, and blueberries are placed among the top fruits and vegetables for nutrients density, with an ANDI score of 132.
ANDI is one of several rating systems for food nutrition, but further research is needed to determine the role of specific foods in disease prevention.