Blueberries are native to North America and they thrive in the glacial soils and the northern climate of Atlantic Canada, Quebec and coastal New England.
Wild (low-bush) blueberries are distinct from their cultivated (high-bush) cousins in a couple of ways.
Unlike cultivated blueberries, the wild version is not planted; they are spread primarily by rhizomes or underground runners, which give rise to new shoots and stems. Wild blueberries also differ in their taste and nutritional profile:
- Antioxidant capacity & polyphenol content – wild blueberries contain more of the powerful antioxidant polyphenolic compounds, especially pterostilbene
- Taste – wild blueberries have a more intense, sweet and tangy taste than cultivated blueberries
- Size – wild blueberries are naturally smaller and more compact (less water content) than cultivated, which means you get more blueberries per kg.
This isn’t to say that cultivated blueberries are nutritionally inferior compared to their wild counterparts. Both are powerhouses when it comes to promoting health and I confidently eat cultivated blueberries and research supports both when it comes to being healthy and yes, tasty.
Blueberries have a pleasant, sweet taste. They’re often eaten fresh but may also be frozen, dried, or juiced. You can even buy blueberry powder which goes great in smoothies and protein shakes. These tasty berries can be used in a variety of baked goods, jams, and jellies, as well as for flavorings.
Pretty much everyone loves blueberries so getting more of them is both easy, and delicious.
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Blueberry nutrition facts
When we think about nutrition, we usually think of essential nutrients such as vitamins and minerals. Those nutrients are called essential either because the human body can’t make enough of them to support health or can’t make any amount at all.
When it comes to blueberries, they’re not overflowing with vitamins and minerals so they’re not nutritious in that classic sense of the word. However, one cup of fresh blueberries has appreciable amounts of:
- Vitamin K1: found abundantly in green vegetables, 1 cup of blueberries has 29 mcg K1 or 36% of your daily value. Vitamin K1, or phylloquinone, is involved in blood clotting and bone health (1) but not to the degree vitamin K2 is.
- Manganese: a lesser-known mineral needed for general energy metabolism (2). One cup of berries provides 25% of the daily value or 0.5 mg
- Fiber: as an indigestible carbohydrate, one cup of blueberries provides 3.6 g of fiber and fiber is known to promote gut health and more (3).
But, blueberries really stand out when it comes to keeping us healthy by providing something else; phytonutrients. Specifically, the interest is with blueberry polyphenols.
How many calories in blueberries?
The calories in blueberries will vary depending if they’re fresh, thawed, frozen, or dried if you’re using a volume measure such as a cup. There will be fewer calories in fresh compared to dried or even thawed, frozen berries because with fresh, there will be fewer blueberries per cup.
Based on a standard 100 g (3.5 ounces) serving (USDA Nutrient Database):
- Fresh blueberries have 57 calories
- Fresh, wild blueberries have 61 calories
- Frozen, unsweetened, unthawed has 51 calories
- Dried blueberries have 317 calories
How many carbs in blueberries?
Based on a standard 100 g (3.5 ounces) serving (USDA Nutrient Database):
- Fresh blueberries have 15 g carbs
- Fresh, wild blueberries have 12 g carbs
- Frozen, unsweetened, unthawed has 12 g carbs
- Dried blueberries have 80 g carbs
Blueberry benefits
The health benefits of blueberries are really all about their polyphenols; plant compounds referred to as both “phytonutrients” and “phytochemicals”. These compounds have been associated with lower rates of cancer, cardiovascular disease including dementia, diabetes, accelerate aging, DNA damage, lower blood pressure and more.
This because human health needs more than just vitamins and minerals to thrive. It’s true, we can survive with adequate amounts of energy, protein, fat. carbs and micronutrients but in order to have the best health, we need the thousands of nuanced compounds found in whole foods.
Flavonoids
Flavonoids are a subcategory of polyphenols; compounds found in plant foods.
Polyphenols reduce oxidation (damage) to various structures like DNA, and the fats, proteins and structural carbohydrates that make up our cells and tissues. This helps to reduce the risk of chronic disease. But polyphenols also positively support an important pathway called Nrf2; a unique protein that controls how your body responds to inflammation and more (4).
Two subcategories of flavonoids that are of interest when it comes to blueberry nutrition are anthocyanins and flavonols
Anthocyanins
Anthocyanins are the main flavonoids in blueberries and are responsible for their health benefits (5, 6, 7). There are lots of different types anthocyanins with one that’s gaining attention: delphinidin (8, 9, 10). Anthocyanins give blueberries their colour.
Flavonols
Flavonols are another subcategory of flavonoids; distinct from others only because of their chemical structures. Two that are found in blueberries are:
Quercetin
This flavonol has been associated with many health benefits, just like its polyphenol siblings. Quercetin intake is associated with lower blood pressure and cardiovascular disease to name a couple (11, 12).
Myricetin
This flavonol may have a number of health benefits, such as helping prevent cancer and diabetes (13, 14).
Health benefits
Are blueberries good for you? You know they are.
1. Maintaining healthy bones
Blueberries and bones? Where’s the calcium, magnesium, and phosphorus you might be thinking. Like many other plant foods that have been shown to protect bones like tomatoes for example, blueberries have been studied for their bone-supporting role.
Blueberries benefit your bones by reducing oxidation which can damage bone-building cells called osteoblasts and by turning on the Sirt1 gene which helps to prevent bone loss as we age (13, 14, 15)
2. Improving your skin
One of the ways your skin ages is by accumulated damage to various proteins and fats found in skin. These are called advanced glycation end products (AGES) which slow down the growth of new skin cells. AGEs also increase skin cell death (16, 17, 18).
Blueberries can support healthy skin and new skin cell production. Where blueberries can help is increases your skin’s defense. Blueberry anti-inflammatory anthocyanins make their way into your skin which helps to reduce the damage and support collagen production (19, 20).
3. Lowering blood pressure
Typically nutritional strategies used to lower blood pressure include reducing excessive intakes of sodium, but also dialing up the intake of potassium (#1), magnesium and calcium.
But there are other ways plant foods can help. Polyphenols work to lower blood pressure in ways that influence how the hormones (renin, angiotensin, aldosterone, etc) that regulate blood pressure work. By adding to your phytonutrient bottom line, blueberries can keep your blood pressure in the Goldilocks zone (21, 22). Blueberries also help to reduce arterial stiffness leading to lower blood pressure (23).
The kidneys play a huge role in blood pressure control. Anything that increases stress in the kidney can lead to higher blood pressure. Blueberries have been shown to prevent this even in a group of smokers (where smoking alone is a risk factor for hypertension) (24, 25).
4. Improving cardiovascular health
Atherosclerosis, or the narrowing of blood vessels, increases the risk for cardiovascular disease (CVD). Despite what conventional wisdom preaches, CVD does not start and stop with LDL cholesterol concentrations.
Atherosclerosis is a complex process that involves inflammation and the oxidation (damaging) of LDL lipoproteins (the little protein structures that transport cholesterol in your blood). When LDL is oxidized (think rusty) it starts an inflammatory process that becomes self-perpetuating. The phytonutrients in blueberries can stop this (26, 27, 28, 29, 30, 31).
5. Reducing cancer risk
One of the ways cancer can start is through the oxidation (damaging) of our various cells’ DNA; this is a normal part of being alive (32, 33). It’s unavoidable but the good news is that your body has built-in ways to counteract this. Extra protection comes from dietary antioxidants. They act as shielding between the oxidative agent and your DNA which is a good thing.
Because blueberries are loaded with antioxidant polyphenols, blueberries, in various forms, can be a big player in preventing cancer (34, 35, 36). Blueberries have been shown to reduce the risk of cancer as well by reducing cancer cell growth, increasing cancer cell self-destruction (apoptosis), prevent cancer cells from ‘talking’ to each other and alter cancer cells’ DNA and their own protein synthesis (32, 37, 38, 39, 40).
6] Maintaining brain function
Here again, polyphenols have been shown to help significantly slow down cognitive decline leading to a lower risk for various forms of dementia including Alzheimer’s disease. Flavonoid-rich foods are associated with better cognition overall (41).
So impressive are they that those with signs of early cognitive impairment showed improvement after 12 weeks of drinking blueberry juice, a concentrated source of blueberry-specific phytonutrients and antioxidants (42, 43). Berries, including blueberries, may reduce the onset of brain aging and dementia by a few years (44).
7. Reduces inflammation
Oxidation and inflammation go hand-in-hand and when science discovered just how potent blueberries were when it came to protecting the body against the ravages of oxidation (think rusting) about 20 years ago, the status of blueberries took off (44, 45, 46, 47).
Antioxidants help to rust-proof our body, as well as, turn on antioxidant producing genes; this all helps to slow the hands of father time and reduce the risk for many chronic diseases.
8. Improves insulin sensitivity (a.k.a. reduces the risk for diabetes)
Blueberries may lower the risk of diabetes as well. Studies have shown that blueberries can improve insulin sensitivity and reduce the risk of type 2 diabetes by up to 26% (48, 49). Blueberries may also affect blood sugar levels directly after eating too. By blocking certain digestive enzymes, blueberries can reduce blood sugar spikes (50).
Like a lot of phenolic/flavonoid-rich plant foods such as olives, apples, raspberries and more, blueberries help cells such as muscle cells, nerves, and even brain cells respond to insulin better thereby helping with carbohydrate metabolism (51, 52)
9. Prevents urinary tract infections (UTIs)
You’re likely thinking what the heck??? Blueberries exhibit antimicrobial effects against one of the main bacteria responsible for UTIs (53). Also, bacteria that infect the urinary tract, of both men and women, do so in part because they can adhere to the inner lining of the bladder or the bladder wall.
Cranberries have long been promoted as was to reduce this effect but blueberries may have a similar effect too. Anthocyanins and proanthocyanins support blueberries in their role in preventing UTIs in women (54).
Buying and storing
Look for fairly firm, sweet-smelling berries with no signs of mould or mildew and no crushed berries in the box. Purchase the smaller lowbush blueberries as fresh as possible. Store, loosely covered, in the refrigerator.
Use the berries within two weeks, but preferably as soon as possible. For optimum flavour, bring refrigerated blueberries to room temperature before serving.
Highbush and lowbush berries freeze well in the same fashion as raspberries and strawberries (whole, in a single layer).
Bottom line
The health benefits of blueberries are numerous, which is a great thing considering blueberries are incredibly versatile and delicious.
They have a smattering of vitamins and minerals but their true superpowers are their phenolic compounds including flavonoids including the subtypes flavonols and anthocyanins.
They’ve been shown to have heaps of health-promoting properties and which benefit your heart, brain function, bones, bladder, ability to use insulin, while reducing your risk for cancer and more.
What’s more, they’re sweet, colorful and easily enjoyed either fresh, frozen, dried, juiced or even as a powder. Eating blueberries on a regular basis will go along way to improving your health.
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Doug Cook RDN is a Toronto based integrative and functional nutritionist and dietitian with a focus on digestive, gut, and mental health. Follow me on Facebook, Instagram and Twitter.