Bilberry fruit: The antioxidant for eye and cardiovascular health

Many red fruits are full of healthy antioxidants, such as anthocyanins, which are found naturally in a number of foods including red wine, certain varieties of cereals and several leafy and root vegetables (aubergines, cabbage, beans, onions, radishes, etc.). But, they are most abundant in coloured fruits such as bilberries¹.

Indeed, the most characteristic compounds of bilberry fruits are colourful polyphenols that belong to the anthocyanin and proanthocyanidin classes. The physiological effects of these compounds are well established and mainly, but not exclusively, related to their strong antioxidant activity.

This property forms the basis of — or at least contributes significantly to — their effects on the vascular system. Most human studies have focused on potential applications such as supporting vascular, eye and digestive tract health.

Vaccinium myrtillus L. contains a higher concentration of anthocyanins than any other berry.² It’s a small deciduous shrub that grows on the hilly heaths and underbrush of Central and Northern Europe.^3–7

The origin of the name Vaccinium is uncertain and may derive from the Latin words vacca (cow) or bacca (berry). The name myrtillus derives more obviously from its similarity to the fruits and leaves of the myrtle plant.^5,6,8

Among the 450 species that belong to the Vaccinium genus, the traditional use of Vaccinium myrtillus L. has been documented since the Middle Ages when its fruits were recommended for a variety of conditions.⁹ From the 16th century onwards, the plant has been systematically mentioned in all major herbal treatises.

Unlike most other berries, Vaccinium myrtillus L.’s growth is extremely difficult; it does not produce clusters of berries, but single or, more rarely, pairs of berries, in limited numbers considering the biomass of the plant. Bilberries are softer and juicier than most other berries and are therefore more susceptible to damage and more difficult to transport. Bilberries cannot be cultivated and are therefore picked from wild plants growing on publicly accessible lands.

Bilberry extract’s positive health effects

Studies show that bilberry extract, rich in anthocyanins, has positive effects on a variety of health challenges. Possibly most well-known and frequently told is the traditional story that, during World War II, the ingestion of bilberry jam (made from Vaccinium myrtillus berries) improved the sight of Royal Air Force pilots on night flights.

Although the truthfulness of this story has been questioned, the effect of anthocyanins in optimising vision has been validated by instrumental techniques, such as computerised perimetry, suggesting that a standardised bilberry extract containing 36% anthocyanins can play an important role in retinal sensitivity.^10,11

Considering this effect, bilberry extract can play a very important role in one of modern health’s most pressing challenges; according to WHO data, it is estimated that approximately 1.3 billion people live with some form of distance or near vision impairment all over the world.

Population growth and ageing will have an ongoing impact on the number of people needing eye care in the future.

Globally, the majority of vision impairment cases is avoidable. There are supportive interventions for eye diseases as well as poor vision.¹²

Other facets of bilberry extract have also been studied in detail. Much human-derived data has confirmed the efficacy of an anthocyanin bilberry extract (36%) on microvascular health. Moreover, its positive effects on venous health have been demonstrated in randomised, double-blind, placebo-controlled human trials done out on hundreds of subjects.^13–19

Furthermore, bilberry anthocyanins are emerging as an alternative dietary strategy to support healthy blood sugar levels and for problems associated with oxidative stress.²⁰

The most studied bilberry ingredient on the market

Mirtoselect is a standardised bilberry extract comprising ≥36% anthocyanins and is characterised by a very specific and consistent HPLC profile that represents the “fingerprint” of the extract. Mirtoselect is the authentic bilberry extract (Vaccinium myrtillus L.) obtained exclusively from fresh fruit harvested when ripe — between July and September.

Indena has been working with bilberry extracts since the early seventies. With time, the company’s interest in the impressive properties of the precious small blue berry has risen and Indena’s standardised extract, Mirtoselect, is not only the most extensively studied bilberry extract available, but also the market leader and benchmark.

Many studies have shown that Mirtoselect can support contrast sensitivity in retinal health, attenuate eye fatigue in school-age children and support eye health in retinal challenges.^21–23 Courtesy of its beneficial effect on vascular circulation, Mirtoselect can optimise oxygen and blood delivery to the eye, supporting the functionality of tear secretion.

Furthermore, the free radical scavenging properties balance oxidative stress, one of the major risk factors of dry eye discomfort. There is a substantial amount of data regarding the supportive role of Indena’s bilberry extract in dry eye challenges: a new randomised, double-blinded, placebo-controlled human study offers further evidence of the efficacy and safety profile of Mirtoselect in terms of supporting physiological tear levels; plus, maintaining a healthy ocular surface may help to support eyes during periods of discomfort and visual stress.²⁴

Furthermore, more than 60 positive human studies, including at least 30 controlled or double-blind studies published in peer-reviewed titles, have validated the efficacy of Indena’s bilberry extract in vascular health.²²

Although the major applications investigated for Mirtoselect are in the fields of vascular and eye health, many surveys and pilot human studies suggest broader positive effects of anthocyanins, including memory amelioration and gastrointestinal and cardiovascular health. In particular, preliminary trials have shown the potential effectiveness of Mirtoselect for metabolic syndrome and glucose metabolism.^25–29

References

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