Over the past few years people have started to take great interest in the amazing properties and uses of blueberries (Vaccinium sect. Cyanococcus). Despite a modest nutritional value, blueberries have become popular thanks to their generous antioxidant content, a source of wonderful health benefits and long-term provider of good health. The berries contain generous amounts of purple and blue-black anthocyanin antioxidants as well as good amounts of vitamins C, K and the antioxidant manganese, dietary fiber and are low in calories. Regular consumption can provide benefits for bones, the nervous, gastrointestinal and immune systems, skin and vision.
Most of the blueberry varieties available on the market come from North America, the US and Canada, South America, Europe, Australia or New Zealand, where they are grown commercially from a single variety occurring naturally in certain parts of North America and some its hybrids. This variety is called the northern highbush blueberry (Vaccinium corymbosum) and is the main cultivated blueberry variety. The northern highbush blueberry occurs naturally in eastern Canada, eastern and southern US and has been naturalized across South America, Europe, Asia, New Zealand and other parts of the world.
Hybrid blueberry varieties resulting from the northern highbush blueberry (Vaccinium corymbosum) and the southern lowbush blueberry (Vaccinium darrowii) account for a significant part of the blueberry market worldwide. Semi-wild and wild blueberries also account for a good deal of local markets in particular. In Europe and Asia, for example, a significant part of of blueberries available in farmer’s markets, health food stores and mini-markets are sourced from the wild. And they are actually different varieties from the North American Vaccinium corymbosum blueberry and its hybrids. A related and very similar looking shrub growing freely in the wild in Europe is called European blueberry or bilberry (Vaccinium myrtillus) while a common variety growing freely in the wild all over the Northern Hemisphere and especially popular in Rusia is called the bog blueberry (Vaccinium uliginosum).
Blueberry vs bilberry vs bog blueberries. The first major difference between the two is that North American blueberries are light green, whitish and translucent inside and have tiny seeds, while bilberries (European blueberries) have darker, red-purple pulp and slightly larger seeds. Bilberries tend to stain more than blueberries and are more flavorful. Another major difference between the two is that North American blueberries have a small protuberance at the end opposite to the stalk, similar to a crown or 5 pointed-star from 5 remaining sepals; bilberries have a round depression at the end opposite to the stalk. Lastly, blueberries grow in clusters, while bilberries grow as singular berries or in pairs. Bog blueberries are more similar to North American blueberries, with a star-shaped protuberance, blue-black skin, whitish, translucent flesh and sweet, but not too strong a flavor.
Blueberry nutrition facts
What vitamins and minerals do blueberries have? The berries are good sources of vitamins C (9.7 mg/100 g), K (19.3 mcg) and manganese (0.336 mg), accounting for 12%, 18% and 16% of the recommended daily allowance for an average adult. They also contain smaller amounts of B vitamins (B1, B2, B3, B5, B6 and B9), vitamin E, calcium, iron, magnesium, phosphorus, potassium and zinc (less than 5% of the recommended daily allowance) and trace amounts of vitamin A.
The nutrient that stands out the most in blueberries nutrition profile is vitamin K, followed by manganese and then vitamin C.
Other nutrients in 100 g of fresh blueberries are:
– dietary fiber: 2.4 g of fiber per 100 g of blueberries
– carbohydrates: 14.49 g
– sugars: 9.96 g
– fat: less than 0.4% (an almost irrelevant amount)
– protein: less than 0.8 g
– water: 84 g
– energetic value: 57 kcal/100 g of fresh blueberries
What are the benefits?
1) Good for blood coagulation. Vitamin K is essential for proper blood coagulation and a sufficient intake can help prevent hemorrhage, nosebleeds and easy bruising. Unless you have a tendency for blood clots or are receiving anticoagulant medication, eating blueberries and leafy greens rich in vitamin K is good for you.
2) Good for bone health. Vitamin K in blueberries is essential for the synthesis of a bone-related protein-hormone that is vital for binding calcium in bones and building healthy bones. It vitamin is also currently being studied for its potential applications in neurodegenerative diseases of the nervous system such as Alzheimer’s and Parkinson’s disease.
3) Anti-inflammatory benefits and immune-boosting action. Vitamin C in blueberries has amazing antioxidant, anti-inflammatory and antimicrobial properties, contributing to reduced inflammation and boosting the immune system. Vitamin K is known to reduce inflammatory cytokine interleukin-6 levels, while antioxidants in the berries have strong anti-inflammatory properties as well. Eating blueberries can provide benefits for inflammatory conditions like rheumatoid arthritis and offer a certain degree of pain relief. Although found in trace amounts in the fruit, zinc remains a great immune system booster.
4) Good for constipation and hemorrhoids. Blueberries have 2.4 g of dietary fiber/100 g, most of which is located in the skin. Regular consumption helps relieve constipation naturally by adding bulk to stools and stimulating peristalsis (contractions of the intestinal tract that move food along). Constipation relief is also good for anyone with hemorrhoids, reducing frequency of flareups and helping manage symptoms. Read more about what foods to eat and to avoid for hemorrhoids.
5) Contain B vitamins for energy metabolism. The B-group vitamins in the berries ensure the proper distribution of energy from carbohydrates, fats and protein synthesis. By processing macronutrients from food and contributing to energy metabolism, B vitamins combat fatigue. Blueberries are also a good source of natural sugars (9.96 g) which further provide quick energy, making them a great food to eat for hypoglycemia (low blood sugar levels).
6) Cardiovascular benefits. The good energetic value of blueberries (57 kcal per 100 g) and fiber content (2.4 g of dietary fiber/100 g) contribute to good weight management which is important for cardiovascular health in the long run. The berries further provide very small amounts of vitamin B6 (0.052 mg), magnesium (6 mg) and potassium (77 mg), three key nutrients for good cardiovascular health. For example, potassium regulates blood pressure by adjusting levels of body fluids and neutralizing the side effects of excess sodium. However, keep in mind that an average adult requires 1.3 mg of vitamin B6, 400 mg of magnesium and 4700 mg of potassium a day.
Studies show there is another way blueberries are beneficial for our cardiovascular system: the antioxidants responsible for ripe blueberry color may help lower triglycerides levels in the blood as well as LDL (bad) cholesterol levels. In individuals with high blood pressure, blueberries are often recommended to help reduce both systolic and diastolic blood pressure, thus keeping high blood pressure under control, a benefit attributed to antioxidants and fiber rather than vitamins and minerals. Vitamin K further contributes by maintain normal calcium metabolism and preventing abnormal calcium deposits that could cause atherosclerosis (plaques on artery walls).
7) Blueberries and diabetes. Despite their relatively high sugar content (9.96 g), blueberries have a low glycemic index (less than 55) which would make them good for diabetes. Having a low glycemic index means that blueberries raise blood sugar levels slowly, steadily and this would make them safe to eat by diabetics. There is also research that suggests pre-diabetics (people with consistently high blood sugar levels) may benefit from eating blueberries and enjoy improved insulin sensitivity. Another reason eating blueberries is good for diabetes is because the berries help manage weight and even lose belly fat, which reduces type 2 diabetes risks.
However, diabetes prevention and management requires more than just eating one good food so it’s important to watch your diet as a whole and try to eat clean and according to your nutritional requirements. Also, regarding how much blueberries can diabetics eat, you need to consult your doctor and find out the recommended amount. Remember blueberries still have quite a lot of sugar and, even though it’s absorbed steadily and does not cause spikes in blood glucose levels, there is a limit to how much of it you can eat in a day. It’s recommended that you eat them raw and avoid adding sugar.
Below is a detailed video on blueberry pruning and care from the University of Maine, teaching us how to prune old blueberry plants, which shoots to keep and which to cut in order to revitalize the plant and enjoy rich fruit bearing.
8) Other benefits. Blueberries are a wonderful source of potent antioxidants such as anthocyanins which give the berries their beautiful deep, dark purple-blue color and many antioxidant polyphenols, manganese and vitamin C. As you may already know, antioxidants are nature’s secret weapon against free radicals, harmful compounds that can produce serious damage to cells and DNA. If consumed fresh, the antioxidants in blueberries can neutralize the harmful effects of free radicals and prevent and repair cell and DNA damage, reducing the risk of developing chronic medical conditions such as cardiovascular disease or cancer in the future.
Studies have shown that these tiny deep, purple-blue colored berries can efficiently improve memory and concentration. The experiments carried out by researchers reached the following conclusions: subjects who ate blueberries on a daily basis for 12 weeks had considerably higher scores on various tests aiming to assess different cognitive functions. Among them, memory and concentration ranked highest.
Antioxidant anthocyanins and other polyphenols and especially vitamin C makes blueberries good for skin, helping collagen production for less wrinkles and anti-aging effects. Vitamin E further helps skin cells retain moisture, contributing to a healthy appearance. Eating blueberries may also hold benefits for eyesight thanks to a generous antioxidant content that may help reduce rates of macular degeneration (loss of central vision). For good eyesight well into old age, dark green, yellow and orange foods are the best you can eat.