Fresh blueberries are one of the most popular summer treats of all time. They are sweet, succulent, full of nutrients, and can be eaten freshly picked as well as incorporated into a variety of recipes.
Blueberries contain a type of flavonoid known as anthocyanins, which are responsible for giving foods like blueberries, cranberries, red cabbage and eggplants their iconic deep red, purple and blue hues. Anthocyanins are responsible for more than just the blueberry’s pretty blue color – they also contribute to the popular fruit’s numerous health benefits.
This MNT Knowledge Center feature is part of a collection of articles on the health benefits of popular foods. It provides a nutritional breakdown of the blueberry and an in-depth look at its possible health benefits, how to incorporate more blueberries into your diet and any potential health risks of consuming blueberries.
One cup of fresh blueberries contains 84 calories, 0 grams of cholesterol, 1.1 grams of protein, 0.49 grams of fat, 21 grams of carbohydrate and 3.6 grams of dietary fiber (14% of daily requirements).
That same one-cup serving provides 24% of daily vitamin C, 5% vitamin of B6 and 36% of vitamin K needs. Blueberries also provide iron, calcium, potassium, magnesium, phosphorus, sodium, manganese, zinc, copper, folate,beta-carotene, folate, choline, vitamin A and vitamin E.
In addition to anthocyanins, blueberries contain a diverse range of phenolic compounds such as quercetin, kaempferol, myricetin and chlorogenic acid – all of which contribute to their antioxidant capacity.
Due to these large amounts of bioactive compounds, blueberries rank very highly on the Aggregate Nutrient Density Index (ANDI), which rates foods based on their vitamin and mineral content, phytochemical composition and antioxidant capacity. Foods that have the most nutrients per calorie have the highest rankings, and blueberries score among the top 20 fruits and vegetables.
Possible health benefits of blueberries
Consuming fruits and vegetables of all kinds has long been associated with a reduced risk of many lifestyle-related health conditions. Many studies have suggested that increasing consumption of plant foods like blueberries decreases the risk of obesity, diabetes, heart disease and overall mortality while promoting a healthy complexion and hair, increased energy, and overall lower weight.
Maintaining healthy bones
The iron, phosphorous, calcium, magnesium, manganese, zinc and vitamin K in blueberries all contribute to building and maintaining bone structure and strength.
Iron and zinc play crucial roles in maintaining the strength and elasticity of bones and joints. Low intakes of vitamin K have been associated with a higher risk for bone fracture, while adequate vitamin K intakes improve calcium absorption and may reduce calcium loss.5
Lowering blood pressure
Maintaining a low sodium intake is essential to lowering blood pressure. Blueberries are naturally free of sodium and contain potassium, calcium, and magnesium, all of which have been found to decrease blood pressure naturally.3
Studies have shown that type 1 diabetics who consume high-fiber diets have lower blood glucose levels and type 2 diabetics may have improved blood sugar, lipids and insulin levels. One cup of blueberries contributes 3.6 grams of fiber.
The Dietary Guidelines for Americans recommends 21-25 grams of fiber per day for women and 30-38 grams per day for men.
Warding off heart disease
The blueberry’s fiber, potassium, folate, vitamin C, vitamin B6 and phytonutrient content, coupled with its lack of cholesterol, all support heart health. The fiber in blueberries helps lower 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. When excessive amounts of homocysteine accumulate in the body, it can damage blood vessels and lead to heart problems.
According to a recent study from the Harvard School of Public Health and the University of East Anglia, regular consumption of anthocyanins can reduce the risk of heart attack by 32% in young and middle-aged women. The study, which was led by nutrition professor Aedin Cassidy, PhD, MSc, BSc, found that women who consumed at least three servings of blueberries or strawberries, showed the best results.
Vitamin C, vitamin A, and various phytonutrients in blueberries function as powerful antioxidants that help protect cells against free radical damage. They inhibit tumor growth, decrease inflammation in the body and help ward off or slow several types of cancer, including esophageal, lung, mouth, pharynx, endometrial, pancreatic, prostate and colon.1
Blueberries also contain folate, which plays a role in DNA synthesis and repair, thus preventing the formation of cancer cells from mutations in the DNA.1
Improving mental health
Population-based studies have shown that consumption of blueberries can reduce the risk of cognitive decline as well as Parkinson’s disease – a neurodegenerative disorder resulting from cell death in parts of the brain.
Studies have also revealed that in addition to reducing the risk of cognitive damage, blueberries can also improve short-term memory loss and motor coordination.4
Because of their fiber content, blueberries help to prevent constipation and promote regularity for a healthy digestive tract.
Weight loss and satiety
Dietary fiber is 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 and reduce appetite, making you feel fuller for longer and thereby lowering your overall calorie intake.
Collagen, the skin’s support system, relies on vitamin C as an essential nutrient that works in our bodies as an antioxidant to help prevent damage caused by the sun, pollution and smoke. Vitamin C also promotes collagen’s ability to smooth wrinkles and improve overall skin texture. Just one cup of blueberries provides 24% of your daily need for vitamin C.
How to incorporate more blueberries into your diet
Blueberries are available fresh, frozen, freeze dried and in jellies, syrups and jams. Make sure to check the label of frozen and dried blueberries for added sugars. When looking for jellies or jams, go for all fruit spreads without the added sweeteners and fillers.
- Use blueberries as fresh toppings on oatmeal, waffles, pancakes, yogurt or cereal for an extra burst of flavor in your breakfast
- Whip up a quick and easy smoothie using frozen berries, low-fat milk and yogurt
- Mix fresh or dried blueberries into a spinach salad with walnuts and feta cheese
- Fold them into muffins and sweet breads or blend them in a food processor with a little water and use as a fresh syrup to top desserts or breakfast foods.
Potential health risks of consuming blueberries
If you are taking blood-thinners such as Coumadin (warfarin), it is important that you do not suddenly begin to eat more or less foods containing vitamin K, which plays a large role in blood clotting.
It is the total diet or overall eating pattern that is most important in disease prevention and achieving good health. It is better to eat a diet with a variety than to concentrate on individual foods as the key to good health.
Written by Megan Ware RDN LD
and Helen Yuan, nutrition intern
Posted by Brenda Hughes – 7 Common Signs of Nutrient Deficiency
Look for stunted growth. If a child is not getting enough nutrients, they will not grow at a normal rate. The rate of growth for a particular child varies with their age. For instance, most people grow rapidly from infants to toddlers, then slow their growth until puberty, when they experience another period of rapid growth. If your child does not grow rapidly during these sensitive periods, they might be suffering a nutrient deficit.
- See a doctor regularly to ensure your child is growing at a normal rate.
Check dental health. Inflammation of the gums, especially, is an early indicator of periodontal disease, which may in turn indicate a nutrient deficit. If your gums are puffy, red, tender, and bleed when you floss or brush, you might not be getting enough nutrients. In advanced cases, you might have loose teeth. See a dentist if you experience any of these dental problems.
- See a dentist at least twice each year for a regular dental checkup. Your dentist will be able to refer you to a nutritionist if they believe it is necessary.
Monitor for increased illnesses. People who do not receive adequate levels of nutrients are more prone to colds and viral infections. A nutrient-deficient immune system cannot fight off illnesses that a healthy one can, leading to a greater frequency of illnesses, more severe illnesses, or both. Nutrient-deficient people might, for instance, experience:
- a sore throat
- a runny nose
- other respiratory tract infections (like pneumonia and bronchitis) and flu-like symptoms
Look for muscle spasms. Muscle spasms are any involuntary contraction or vibration of the muscle tissue. If you suddenly develop facial tics – for instance, a sudden upturning of the mouth, or scrunching up of the nose – you might be nutrient deficient. Eye twitches (closing your eyes with excess force or experiencing difficulty in keeping your eyelids stable) could also indicate you need more nutrients. Painful cramps in your legs (especially your calves or thighs) are also reported in some cases of nutrient deficits.
- You might be experiencing a magnesium deficit, since magnesium helps regulate the neuromuscular system that allows our muscles to relax.
- Deficits of B vitamins and calcium might also contribute to muscle spasms.
Look for thyroid problems. Some kinds of nutrient deficiencies – especially iodine deficiency – lead to imbalances in the thyroid and an inability to produce and regulate hormones properly. Signs that your thyroid might be acting up include weight gain, deceased libido, goiter (swelling of the thyroid gland that usually produces a large bump in the neck), hair loss, and infertility
Look for eye problems. In a developing child, a vitamin A deficit could lead to blindness or visual impairment. If your child cannot see well, or suffer from night blindness (an inability to see in the dark), they might not be getting enough vitamin A. Other eye problems like cataracts and macular degeneration also occur in people who have a deficit of vitamin C, vitamin E, zeaxanthin, and zinc.
- You can detect macular degeneration and cataracts by paying attention to any loss of quality in your vision. Blurriness, clouded vision, and increased sensitivity to light are common symptoms.
Look for signs of malnutrition. Nutrient deficiencies are one form of malnutrition. Signs of this condition include, notably, sunken eyes and a bony frame with visible ribs. The skin of a nutrient deficient person will be leathery, dry, and inelastic. Jaundice (yellowing skin) could also occur. Finally, a malnourished person will usually feel lethargic and have low energy levels overall.
- Malnutrition usually indicates that someone is not getting enough calories or is not getting a balanced diet. Malnutrition might also indicate that someone is getting too many calories.
See a doctor. The many symptoms of nutrient deficits are common in many other conditions and diseases. Therefore, in order to rule out other possibilities, it is important to see a doctor and get a professional diagnosis of your condition. Doctors can draw and analyze your blood to determine concentrations of key nutrients. Some doctors might conduct a cellular analysis as well as (or instead of) a blood analysis. If you suspect you or your child has a nutrient deficit, see a doctor and explain why you’re concerned about your nutrient levels.
- Your doctors might not need to conduct a blood analysis if signs and symptoms of a nutrient deficit are obvious enough.
- Your doctor might run tests to look for levels of specific nutrients, or just do a general screening for major nutrients.