Bilberry (1981, '87, '95, '02, '15) & Diabetic Retinopathy
See more about diabetic retinopathy treatment and information.
The family of anthocyanosides are natural antioxidants, which most famously include bilberry (Vaccinium myrtillus), a European type of blueberry. Holistic doctors have known about the benefits of anthocyanosides (decreasing blood vessel leakage and increasing antioxidant levels) since the 1970s or earlier, but in the last few years it has received a lot of attention due to new research.
This study aimed to determine whether bilberry actually helped to prevent retinal difficulties caused by diabetes. The damage results from impaired blood vessel functioning and consequent growth of extraneous capillary growth (neovascularization or micro-neovascularization) which distort and damage the retina. Bilberry was given to lab animals with uncorrected diabetes for six weeks. The treatment reduced bio-markers of diabetic retinopathy which included neovascularization, and degradation of three different zonula occludens (protein protectors of capillaries). The researchers reported that bilberry may delay or prevent the onset of early diabetic retinopathy.
Kim, J., Kim, C.S., Lee, Y.M., Sohn, E., Jo, K., et al. (2015). Vaccinium myrtillus extract prevents or delays the onset of diabetes--induced blood-retinal barrier breakdown. Int J Food Sci Nutr, Mar;66(2):236-42.
Blueberries also contain significant amounts of valuable anthocyanins. Although research had previously been done with lab animals, these scientists wanted to find out whether the benefits extended to humans. Subjects given a high-fat meal with freeze-dried blueberry powder that contained 25 different types of anthocyanins. Nineteen of those anthocyanins were consequently detected in the blood samples of the subjects. In addition an increase in antioxidants in the blood samples was detected.
Mazza, G., Kay, C.D., Correll, T., Holub, B.J. (2002). Absorption of anthocyanins from blueberries and serum antioxidant status in human subjects. J Agric Food Chem, 50:7731-7.
Researchers have noted that bilberry extracts could improve vision sharpness and help faster adaption to changing light conditions. European physicians already recommend bilberry extracts for other eye complaints such as retinitis pigmentosa, and diabetic retinopathy.
One study assessed the effectiveness of a bilberry extract (anthocyanosides) in animals finding that vascular permeability is decreased. This means that blood barrier permeability is normalized.
"Bilberry Fruit," The Lawrence Review of Natural Products, October 1995, Pages 1-2.
In a small trial, 79% of 37 patients for whom opthamologists could detect visible diabetic retinal abnormalities gained some benefit from taking 160 mg of bilberry extract twice daily, compared to 0% improvement in a placebo control group. Furthermore, 86% of those with abnormalities of angiography findings showed moderate to considerable improvement.
Perossini, et al. (1987). Annali Di Ottalmologia E Clinica Oculistica.
Thirty one patients with various types of retinopathy who were put on anthocyanosides showed a positive influence on both vascular permeability and resistance to hemorrhage. Those with diabetic retinopathy had the largest effect. Long term use of these plant nutrients is helpful in improving vascular permeability.
Sharrer A., Ober M. (1981). Anthocyanosides in the treatment of retinopathies (author's transl). Klin Monatsbl Augenheilkd, May;178(5):386-9.