If you grew up among the
heaths, moors, and woodlands of northern Europe, or
for that matter are a wild foods enthusiast in the
Rocky Mountains of the United States, you would
probably be familiar with bilberry as the stuff of
which jam or pies are made. Now, however, the
average consumer is most likely to find bilberries
in the form of purple-colored gelatin capsules in
dietary supplement products. Bilberry, Vaccinium
myrtillus, is a relative of blueberry in the
heath family. The genus Vaccinium includes
upwards of 450 species which occur in cool
temperate regions and mountains of both the
northern and southern hemispheres. Many are
deciduous or evergreen shrubs with edible fruits
including blueberries, buckberries, huckleberries,
farkleberry, cranberry, whortleberry, crowberry,
and bilberry. Bilberry is small shrub to
about a foot in height with sweet, plump blue-black
berries. It grows in heaths and woods of northern
Europe, western Asia, and the Rockies of western
North America. Bilberry is common in northern
Europe, as well as mountains of southern Europe,
absent only from southern Italy and the Iberian
Peninsula. It thrives in damp acid soils, damp
woods and sandy and rocky soils, covering vast
areas, and is a scrub shrub of high mountains. Its
range extends to Western Mongolia, then jumps the
Pacific to Western North America, occurring from
British Columbia, southward from Utah to Arizona
and New Mexico. Commercial harvest of the fruits is
from wild regions of Europe when ripe from July
through September. The genus name Vaccinium derives from the old Latin name
used in the works of Virgil and Pliny. The species
name "myrtillus" refers to the resemblance of the
leaves to those of myrtle. In England the plant is
known as bilberry, bleaberry, blueberry, as well as
common whortleberry.
Bilberry
Leaves
The leaves have been used as a tea substitute.
In Edible Native Plants of the Rocky
Mountains (The University of New Mexico Press,
1967), H. D. Harrington notes that of the leaves of
all Rocky Mountain Vaccinium species, his
favorite was bilberry leaf tea, which he stated was
available at one of the local grocery stores in
Fort Collins, Colorado. Traditionally the leaves
have been used for astringent, tonic,
anti-inflammatory, and antiseptic qualities.
Studies have shown that the leaves have weak
anti-diabetic activity and have been used in
various herbal combinations as a treatment for
diabetes. The leaves contain a component
(glucoquinine) which experimentally has been shown
to lower blood sugar levels. The leaves are
primarily used in the form of a tea. Leaf
preparations have also been suggested by modern
researchers in Germany as a potential treatment for
rheumatism and gout, given the presence of quinic
acid in the tea of the dried, heated leaves. The leaves, however, are
primarily used as a folk remedy, and are not nearly
as important as the fruits. The German Commission E
monographs, the basis of herb regulation in
Germany, has a negative monograph on bilberry
leaves. According to the monograph the leaves and
their preparations are traditionally recommended
for use in diabetes mellitus, and the prevention
and treatment of gastrointestinal tract conditions,
arthritis, gout, skin ailments, hemorrhoids, poor
circulation, heart problems, blood purification,
and to stimulate metabolic processes. While there
are a few older laboratory studies supporting a
theoretical basis for potential anti-inflammatory
and blood-sugar lowering potential, there is not
sufficient scientific data to support the
traditional use of the leaves. Therefore, because
the claimed applications are not well-documented,
bilberry leaves are not approved for their
traditional uses. Safety issues are also a
question. Animal studies have shown that the leaves
can cause anemia, disturb tone of the
gastrointestinal system, and adversely effect
absorption of nutrients. Safety problems probably
relate to high tannin content of the leaves.
Bilberry
Fruits-Food
and
Medicine
Bilberry has been valued for centuries as a
nutritious food and a wild edible delicacy. The
berries, best known as an edible fruit, are an
ancient food in northern Europe. In an 1862 work, The Useful Plants for Great Britain, C. P.
Johnson noted that the berries have a sweetish, but
slightly acid taste and are best eaten cooked
rather than. They have long been sold in English
markets. In Scotland the berries are eaten with
milk, and used for pies, tarts, syrups, and
jellies. The berries have also been used for
wine-making. In the 1870s, a USDA report noted that
the fruits were a favorite food of various Indian
groups of the Rocky Mountain region. The use of bilberry fruits
as an herbal medicine emerges in the Middle Ages.
Saint Hildegard of Bingen (1098-1179), the first
women to write an herbal, recommended the plant for
inducing menstruation. In the 16th century German
herbalists, such as Hieronymus Bock, recommended
the berries for treatment of bladders stones, liver
disorders, and in syrups for coughs and lung
ailments. In the eighteenth century,
use of bilberry fruits became widespread among
herbalists and physicians, particularly in Germany.
Berry preparations were used for various intestinal
conditions, as well as typhoid fever, infections of
the mouth, skin, and urinary tract infections, and
in gout and rheumatism. By the early part of this
century, the dried berry tea was used as an
astringent for diarrhea and dysentery, a diuretic,
cooling nutritive tonic, to prevent scurvy (vitamin
C deficiency), and to stop bleeding. It is also
used as an astringent and disinfectant mouthwash
for mouth inflammations. Modern interest in
bilberry arose through serendipity after the Second
World War. During night bombing missions, British
Royal Air Force pilots reportedly experienced an
improvement in night vision after eating bilberry
jam. In the mid 1960s, reference to these
observations eventually led to the first laboratory
and later clinical studies on the effects of
bilberry fruit extracts on the eyes and vascular
system.
What's
in the fruits?
The effectiveness of the fruit extracts was
linked to a group of compounds called
"anthocyanosides." These compounds are derivatives
of anthocyans - the pigments responsible for the
red, blue or violet colors in flowers and fruits.
The majority of studies on bilberry have involved
extracts purified to contain from 25 to 36 percent
anthocyanosides. At least fifteen different
anthocyanoside compounds have been identified in
bilberry extracts. Most standardized bilberry
extracts available as dietary supplements on the
American market contain 25 percent
anthocyanosides. Like most herbal
medicines, positive effects obtained from the plant
are not necessarily attributed to only one chemical
component. In addition to anthocyanocides, bilberry
fruits contain tannins (up to 7 percent) as well as
several alkaloids including myrtine and epimyrtine.
At least twelve different phenolic acids have been
identified from the fruits along with three
glycosides of quercetin, including quercitrin,
isoquercitrin, and hyperoside. All of these
components, in one way or another, could help to
contribute to bilberry's beneficial effects.
Modern
Use
In European herbal medicine, bilberry fruit
preparations are now used to enhance poor
micro-circulation, including eye conditions such as
night-blindness and diabetic retinopathy. The
German Commission E has produced a positive
monograph on bilberry fruits, which are allowed in
that country for the treatment of acute diarrhea,
and for treatment of mild inflammations of the
mucous membranes of the mouth and throat. Modern laboratory studies
on bilberry fruit extracts have confirmed a number
of activities including antioxidant effects, an
ability to inhibit aggregation of blood platelets
(reduce stickiness, hence a tendency to clotting of
blood cells), produce a slight relaxation effect on
vascular smooth muscles, and a possible role in
reducing factors associated with chronic
inflammatory diseases. Extracts of the fruit have
also been shown in laboratory experiments to
inhibit enzymes such as elastase, which can cause
the degradation of collagen. This can lead to a
reduction in factors associated with inflammatory
conditions such as atherosclerosis, pulmonary
emphysema, and rheumatoid arthritis.
Bilberry
and the Vascular System
Among the most credible uses of bilberry relate
to conditions of peripheral vascular disorders,
especially those involving capillary fragility.
Tiny blood vessels (capillaries) can become
fragile, common in aging populations, producing
capillary fragility. This can lead to more frequent
bruising. Weak capillaries are associated with poor
blood circulation to connective tissues, and have
been related to inflammatory conditions such as
arthritis. Bilberry anthocyanosides serve to
strengthen capillaries by protecting them from free
radical damage. They also stimulate the formation
of healthy connective tissue, and aid in the
formation of new capillaries. Bilberry may reduce
blood platelet stickiness (platelet aggregation), a
risk factor associated with atherosclerosis. Given
its proven ability to help reduce the fragility of
blood capillaries, bilberry fruit products have
been studied in clinical trials involving patients
suffering from a wide range of diseases including
diabetes, arteriosclerosis, hypertension, varicose
veins, liver disorders, peptic ulcers, and other
conditions in which capillary fragility may play a
role in causing symptoms secondary to the disease
itself. Most studies have been by French or Italian
researchers and published in those
languages. Studies in the mid to late
1960s showed that bilberry extracts produced a
reduction in symptoms associated with decrease
resistance in the blood capillaries such as
bruising, blood in the stool, and minute, pin-head
sized bleeding spots on the skin. In various
clinical studies with patients suffering from water
retention in the lower limbs with varicose vein
symptoms, the bilberry extracts helped to reduce
subjective symptoms such as a feeling of heaviness,
pain in the legs and ankles, and sensations of
burning, pricking or numbness of the skin. One
double blind placebo-controlled study on 47
patients with various peripheral vascular disorders
also reported subjective improvement in the
symptoms enumerated above, as well as an
improvement in swelling (due to water retention)
and movement of finger joints in patients suffering
from Raynaud's syndrome, a condition involving
spasms of the digits with blue coloration, probably
relating to poor micro-circulation to the
extremities. The syndrome is named after a Paris
physician, Maurice Raynaud (1834-1881). Results of clinical
studies involving more than 700 patients with
various conditions related to poor
micro-circulation in cases of atherosclerosis, a
tendency to bruising, hemorrhoids and varicose
veins have shown the extracts help reduce damage
from free radicals (antioxidant effects) and
promote healthy circulation to the extremities.
These studies involve extracts of the fruits
standardized to contain 25 to 36 percent
anthocyanosides. The tea has also been shown
useful, mostly through clinical experiences (rather
than controlled studies) for diarrhea, and
inflammation of the mucous membranes of the mouth
and throat.
Bilberry
and Eye Conditions
Based on anecdotal reports from British air
force pilots of increased night vision after eating
bilberry jam, in the 1960s French researchers set
out to discover if bilberry had any potential for
the treatment of eye diseases. In experiments with
rabbits, a mixture of the anthocyanosides from
bilberry was found to increase the animals' ability
to adapt to darkness. The improvement in visual
function was related to an increase in the
regeneration rate of rhodopsin, a purple pigment
essential for helping the rods in the eye adapt to
light and dark. The retina located at the back of
the eye is a specialized structure that responds to
light. Special cells called rods and cones in the
retina are what makes it work. The cones are
adapted to sense details and distinguish colors.
They are like the color and tint adjustment dials
on a television. The rods detect lightness and
darkness. They are like a television's contrast and
brightness adjustments. Bilberry's ability to speed
up the regeneration of rhodopsin in the rods helps
the retina to improve adaptation to light and dark.
Studies on anthocyanosides from bilberry both in
laboratory and animals experiments have also been
shown to modify enzyme processes that are involved
in producing damage to the retina. A number of clinical
studies have been carried out with bilberry fruit
extracts either alone or in combination with
beta-carotene and vitamin E for disorders related
to impaired photo-sensitivity or poor
micro-circulation to the retina. Four studies were
published in the late 1960s by Italian researchers
in Italian scientific periodicals that showed that
both healthy individuals and patients with visual
disorders had a significant improvement in night
vision, more rapidly adapted to darkness, and had
faster restoration of visual acuity following
exposure to bright flashes of light after taking a
bilberry extract. Additional studies on
air-traffic controllers, airplane pilots and truck
drivers also showed that a standardized extract of
bilberry fruits helped to improve night vision and
enhanced adjustment to darkness. In two clinical
trials, Italian researchers found that 76 percent
of patients with myopia (short or near sightedness)
had a marked improvement in retinal sensibility.
The patients were given 150 mg per day of a
bilberry fruit extract for 15 days, along with
vitamin A. Diabetic retinopathy is a
condition secondary to diabetes mellitus, in which
there is non-inflammatory degeneration of the
retina. At least three double-blind
placebo-controlled studies, in which patients were
given 320 to 480 mg per day of a
high-anthocyanoside-containing extract for 30 days
to twelve months showed positive improvements. A
significant reduction or disappearance of
hemorrhages in the retina was observed. These
studies were conducted by Italian researchers from
1982 to 1987.
Bilberry
- The Future
Most studies on bilberry, as previously stated
were conducted by French or Italian researchers,
mostly in the 1960s and 70s. Much of the research
is published in relatively obscure French or
Italian scientific journals in the languages of the
authors. The fact that the results are dated, and
difficult to assess due to language barriers and
lack of availability, makes some scientists slow to
accept the results. A number of pharmacological and
clinical studies have involved the isolated
anthocyanosides used in injectable forms. Clearly
more studies, involving a great number of patients
using oral dosage forms are needed if we are to
accept the claims made for bilberry fruit
extracts. While more studies are
needed to prove effectiveness, safety is
well-established. A post-marketing retrospective
study followed 2,295 patients who had been
prescribed a 36% anthocyanoside standardized
bilberry fruit extract. Researchers showed positive
results for improvement of symptoms associated with
lower limb venous insufficiency, conditions of
capillary fragility and altered permeability of
blood capillaries, disease-related changes in
microcirculation of the retina, and to reduce
itching, inflammation and swelling following
surgical removal of hemorrhoids. No adverse effects
were reported even for prolonged use of the
extract. The German Commission E monograph on
bilberry fruits lists no known contraindication,
interactions with other drugs, or side effects.
Given its long history of food use, and clinical
experience with extracts over a thirty year period,
safety is not at issue. In the United States,
bilberry dietary supplement products including
tablets and capsules of the dried fruits are
available, as well as products standardized to 25%
anthocyanosides. Standardized products will give
more predictable results. The dried ripe berries
are used in a dose of 20 to 60 g daily, prepared as
a tea, divided into three doses. Standardized
products are taken at a dose of 120 to 480 mg per
day, (usually 340 mg) divided into two or three
doses. Whether you consider it a
wild edible delicacy or a dietary supplement,
bilberry is an herb that's here to stay.
Recommended
Reading:
- Blumenthal, M. eds.,
S. Klein, trans. German Bundesgesundheitsamt
(BGA) Commission E Therapeutic Monographs on
Medicinal Products for Human Use. (English
translation). American Botanical Council,
Austin, Texas (in press, due early
1997).
- Brown, D. 1996. Herbal Prescriptions for Better Health.
Rocklin, Calif.: Prima Publishing.
- Cunio, L. 1993. Vaccinium myrtillus, Australian
Journal of Medical Herbalism, 5(4):81-
85.
- Leung, A. Y. and S.
Foster. Encyclopedia of Common Natural
Ingredients Used in Foods, Drugs and
Cosmetics. Second Edition. New York: John
Wiley & Sons, 1996.
- Morazzoni, P. and E.
Bombvardelli. Vaccinium myrtillus L. Fitoterapia, 67(1):3-29,
1996.
- Tyler, V. E. The
Honest Herbal, third edition, Binghamton,
New York: Pharmaceutical Products Press,
1993.
- Tyler, V. E. Herbs
of Choice - The Therapeutic Use of
Phytomedicinals, Binghamton, New York:
Pharmaceutical Products Press, 1994.
- Weiss, F. R. Herbal
Medicine (translated from German by A. R.
Meuss). Beaconsfield, England: Beaconsfield
Publishers, 1988
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