To See or Not to See: The Science Behind Bilberry

1. NMR News: Volume 3, Issue 3, March 2010
To See or Not to See: The Science Behind Bilberry
By: Charles Spielholz, Ph.D.
B
ilberry (genus Vaccinium, several different (2,3). In addition, a mechanism of action has not
species with Vaccinium myrtillus being the been established for how bilberry may be
most common) is shrub that bears fruit. improving night vision. Clearly, additional research
Related to blueberries, the plant is found in establishing both a mechanism of action and
England, mainland Europe, Scandinavia, Turkey, employing large scale clinical trials is required
and Russia. Because bilberry does not grow easily, before a role can be established for bilberry in night
it is not cultivated to any significant extent. Like vision.
other edible berries, bilberry fruit can be eaten
directly or made into jams, jellies, pie fillings, juice, There has been one report suggesting that
or flavors for ice bilberry flavonoids
creams, sorbets and provide improvements in
other desserts. The intraocular pressure
berries of bilberry resulting from glaucoma
have been associated (4). However, there has
with several health been no follow-up
claims regarding evidence in the medical
vision. Therefore a literature that confirms
brief examination of this 1985 report.
these claims will be Reports in the
made. literature suggest that a
Consumption diet high in
of the bilberry plant has been associated with anthocyanosides slowed the development of
improvements in vision, protection against cataracts in laboratory rats (5) and propose a
glaucoma and the prevention of cataracts. reduction of aldose reductase enzyme activity as a
Anthocyanosides, a flavonoid pigment with possible mechanism for this event (6). However, no
antioxidant properties found in bilberries, is the significant follow-up research has been reported in
component of pharmacological interest. Claims the medical literature since these reports appeared
regarding improvement in vision center on in the mid-1980s and there have been no reports
improved night vision. However, studies are mixed that tested bilberry extract directly in a clinical trial
with one clinical trial indicating an improvement in in the United States.
night vision (1) and others indicating no effect
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2. NMR News: Volume 3, Issue 3, March 2010
A few reports in the literature indicate that 4) Caselli L. 1985. Clinical and electroretinographic
bilberry may protect the retina against damage from studies on activity of anthocyanosides. Arch Med Int. 37:
oxidation (7-9), diabetes (10), and angiogenesis 29-35.
(11). There have also been reports concerning the 5) Hess HH, Knapka JJ, Newsome DA, Westney IV,
significance of diet on inherited retinal dystrophy in Wartofsky L. 1985. Dietary prevention of cataracts in the
the rat (12) thus suggesting that diet may play a role pink-eyed RCS rat. Lab Anim Sci. 35:47-53.
in the normal health and functioning of the retina.
One report suggested that since bilberry extracts, as 6) Chaudry PS, Cambera J, Juliana HR, Varma SD.
well as other antioxidants, reduced damage to DNA 1983. Inhibition of human lens aldose reductase by
flavonoids, sunindac and indomethacin. Biochem
by a certain epoxide (A2E-epoxide) in retinal
Pharmacol 32:1995-1998.
pigment epithelial cells maintained in the laboratory
(8) that it is perhaps not impossible that damage to 7) Jang YP, Zhou J, Nakanishi K, Sparrow JR. 2005.
the retina from light induced epoxidation may be Anthocyanins protect against A2E photooxidation and
due to a deficiency of antioxidants (8). If further membrane permeabilization in retinal pigment epithelial
research proves this relationship to be true, then cells. Photochem Phgotobiol 81:529-536.
dietary approaches to retinal diseases, that include
8) Sparrow JR, Vollmer-Snarr HR, Zhou J, Jang YP,
bilberry, will be worth exploring. Jockusch S, Itagaki Y, Nakanishi K. 2003. A2E-epoxides
damage DNA in retinal pigment epithelial cells. J Biol
Evidence indicating a role for bilberry,
Chem. 278:18207-18213.
either as whole berries or an extract, is still in the
early stages. Additional research, including 9) Matsunaga N, Imai S, Inokuchi Y, Shimazawa M,
laboratory bench research to elucidate a mechanism Yokota S, Araki Y, Hara H. 2009. Bilberry and its main
of action, and clinical trials, to show a benefit to constituents have neuroprotctive effects against retinal
vision in humans, are required to unambiguously neuronal damage in vitro and in vivo. Mol Nutr Food
verify health claims regarding bilberry and eye Res. 53: 869-877.
health. 10) Chung HK, Choi SM, Ahn BO, Kwak HH, Kim JH,
Kim WB. 2005. Efficacy of troxerutin on
References
streptozoctocin-induced rat model in the early stage of
1) Sala D, Rolando, M, Rossi, PL, Pissarello L. 1979. diabetic retoniopathy. Arzneimittelforschuhng 55:573-
Effect of anthocyanosides on visual performance at low 580.
illumination. Minerva Oftalmol. 91:283-285.
11) Matsunaga N, Chikaraisshi Y, Shimazawa M,
2) Muth ER, Laurent JM, Jasper P. 2000. The effect of Yokota S, Hara H. 2007. Vaccinium myrtillus (Bilberry)
bilberry supplementation on night visual acuity and extracts reduce angiogenesis in vitro and in vivo. Evid
contrast sensitivity. Altern Med Rev. 5:164-173. Based Complement Alernat Med. 7:47-56.
3) Zadok D, Levy Y, Glovinsky Y. 1999. The effect of 12) Pautler EL, Ennis SR. 1984. The effect of diet on
anthocyanosides in a multiple oral dose on night vision. inherited retinal dystrophy in the rat. Current Eye Res.
Eye (Lond). 13:734-736. 3:1221-1224.
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