Blueberries and heart disease

Berries are a good source of polyphenols, especially anthocyanins, micronutrients, and fiber and these constituents have been associated with improved cardiovascular risk profiles.

New findings published in the American Journal of Clinical Nutrition show that eating 150g of blueberries daily resulted in sustained improvements in vascular function and arterial stiffness — making enough of a difference to reduce the risk of cardiovascular disease by between 12 and 15%.

This may be because blueberries are high in naturally occurring compounds called anthocyanins. Anthocyanins comprise the largest group of natural, water-soluble, plant pigments and impart the bright colors to berry fruits and to flowers.

Blueberries are believed to have one of the highest antioxidant levels of all common fruits and vegetables. The main antioxidant compounds in blueberries belong to a family of polyphenols antioxidants called flavonoids.

One group of flavonoids in particular — anthocyanins — is thought to be responsible for much of these berries’ beneficial health effects. Anthocyanins are water soluble pigments that can appear red, black, blue, or purple. These flavonoids are present in the tissues — including the stems, leaves, flowers, roots, and fruits — of many higher plants.

New research zooms in on the cardiovascular effects of blueberries and finds that anthocyanins — the phytochemicals that give blueberries their color — mediate the beneficial effects that this fruit has on the cardiovascular system. The researchers published their findings in The Journals of Gerontology: Series A 2019.
Blueberries and heart disease

Flavonoid content of bilberry

Bilberries (Vaccinium myrtillus L.) (Ericaceae) are a perennial dwarf shrub native European blueberry, closely related to the North American blueberry species (Vaccinium corymbosum L.), both part of the widespread genus Vaccinium containing over 200 species.

Bilberry grows in the area of Europe and Asia, most abundantly in Scandinavia, Eastern Europe and at higher elevations in Southern Europe.

Despite their similarities, berries differ in their phytochemical content, such as flavonoids and anthocyanins, of both plants and fruit. Flavonoids are a class of secondary metabolites in plants that are involved in many important functions.

Bilberry is one of the best natural sources of anthocyanins; however, other compounds, such as stilbenes and iridoid glycosides, are also found in its berries.

The quantity of the main anthocyanins found in bilberries is more than twice the one found in blueberries. Furthermore, anthocyanin content seems to be higher in wild bilberries as compared to the cultivated ones.

These polyphenolic components give bilberry its blue/black color and high antioxidant content, and they are believed to be the key bio-actives responsible for the many reported health benefits of bilberry and other berry fruits.

The leaves of this plant, traditionally used as a folk medicine for the treatment of diabetes, have recently been proposed as a potential source of phenolic compounds with many prohealth properties.

The less explored organs of bilberry, such as the stems and rhizomes, have also been found to contain phenolics with various biological activities.

Although bilberry is promoted most commonly for improving vision, it has been reported to lower blood glucose, to have anti-inflammatory and lipid-lowering effects, and to promote antioxidant defense and lower oxidative stress.
Flavonoid content of bilberry

Blueberries can help to fight cancer

Blueberries are a sweet, succulent fruit grown in many parts of the world. They are rich in phytochemicals called flavonoids. Flavonoids such as anthocyanin found in blueberries have a different chemical structure compared to other common antioxidants such as vitamin C which makes them three to four times more potent.

Antioxidants neutralize the effect of ‘free radicals’ which are unstable molecules that can attack human cells and damage their DNA.

Study published in 2007 in Clinical Cancer Research conducted by Rutgers University and USDA found that pterostilbene, a compound present in blueberries is of great interest for the prevention of colon cancer. Pterostilbene (trans-3,5-dimethoxy-4-hydroxystilbene) is a natural dietary compound and the primary antioxidant component of blueberries.

The pigments in blueberries are powerful antioxidants. The pigment provides the characteristics color of blueberries. They have been determined to be a much-heralded chemical warrior against heart disease and also cancer. The antioxidant fight cancer is primarily located in the blue pigment in the berry.

The antioxidants in blueberries also may protect against disease like Parkinson’s, Alzheimer’s and other neurodegenerative disease.

In addition to their powerful anthocyanins, blueberries contain another antioxidant compound called ellagic acid, which blocks metabolic pathways that can lead to cancer.
Blueberries can help to fight cancer

Phenolic compounds in blueberries

Phenolic compounds are generally good antioxidants, thus they afford protection against tumor promotion by inhibiting oxidative stress induced by tumor promoters.

Blueberries are rich sources of phenolic compounds, including phenolic acids, anthocyanins, proanthocyanidins and other flavonoids.

The most abundant flavonoids are kaempferol, quercetin and myricetin and among the phenolic acids p-coumaric aicd, coffeic acid, ferulic aicd, p-hydroxybenzoic acid, gallic acid and ellagic acid are the most common.

The content of phenolic compounds in blueberries is influenced by the degree of maturity at harvest and by the cultivar.

In blueberry, catechin is the major flavonoid. They can reach 387 mg/100g fresh weight, whilst epicatechin ranged from 34 to 129 mg/100 g fresh weight and total anthocyanins range from 84 to 113 mg/100g fresh weight.

Quercetin is another major flavonoid in blueberry. Blueberries also contain high level of proanthocyanidins. 

Phenolic compounds present in berries have a varying effect in inhibition of the growth of pathogenic bacteria. They also exhibit a wide range of biological effects, including antioxidant and anti-carcinogenic. 

Epidemiological evidence suggests that high consumption of flavonoids, which are an important component of berries, may provide protection against coronary heart diseases, cardiac stroke, lung cancer and stomach cancer.
Phenolic compounds in blueberries

Blueberries as Herbal Medicine

Blueberries as Herbal Medicine
Blueberries have a rich folkloric history as an herbal medicine. At one time, a tea made by steeping the roots of the blueberry bush was thought to calm women during childbirth. Native Americans credited blueberry juice and syrup a cure for coughs. Scandinavians used dried blueberries to treat children with diarrhea.

Lately scientific evidence emerging from labs all over the country tells us that blueberries are potent little disease warriors. These blue beauties are packed with powerful antioxidants called anthocyanins – the pigment that makes them blue – and other flavonoids, including condensed tannins. In fact, when compared with the antioxidants in dozens of other fruits and vegetables, those in blueberries have a greatest capacity to destroy unstable oxygen molecules called free radicals. Without antioxidants, free radicals careen around the body attacking cells and causing damage that paves the way for cancer and heart disease. Antioxidants also may hamper the build-up of LDL cholesterol and reduce the risk of blood clots that cause strokes.
Blueberries as Herbal Medicine