Bilberry, also called as European blueberry, is similar species to the blueberry, cranberry (which is served with turkey at Thanksgiving in USA), and huckleberry in USA.
As a fruit of bilberry tree which is widely distributed around the world, it has been used as a medicinal herb for eyes. Bilberry is mostly harvested from the wild with 5 times more anthocyanin compared to the blueberry which hass strong anti-oxidant activity. Large amount of anthocyanin is included in the deep purple fruits. Especially, the content of biologically active anthocyanin is 25% in bilberry which is extremely high compared to other fruits containing approximately 0.1~0.25% of anthocyanin. It makes the vascular walls strong, prevents inflammatory reactions, and reinforces cartilage tissues. According to a study in Europe, it also helps stop the bleeding after surgery which is assumed to be contributed by the effect of reinforcing the vascular walls.
Upon aging, the supply of nutrition to the crystalline lens decreases to cause problems in the eye proteins leading to the cloudy lens in cataract. According to a publication, vitamin E and bilberry stops the progress of cataract. In <Prescription for natural treatment>, M.D. James Balch says that bilberry extracts contain bioflavonoids which remove the harmful substances from retina to prevent the cataract. Other than that, fruits in the same kind as bilberry are known to contribute to the improvement of glaucoma, macular degeneration, night blindness, and retinopathy. Clinically bilberry has been given to the pilots in UK during the World War II to enhance their night sight during the night flight. In North America, it is very popular among many people who use their eyes a lot. It is more effective when taken with other vitamins. Especially, it is highly recommended with carrot which has high contents of carotinoid, a precursor of vitamin A and beta-carotene. Also, it is good with wheatbuck which has high content of rutin and other food with high content of vitamin C.
Anthocyanin included in bilberry has the most potent anti-oxidant activity out of all the anti-oxidant substances.
Anthocyanin helps the visualization process in retina mediated by Rhodopsin, a pigment which is degraded by light and resynthesized again. This continuous reaction is transferred to the visual area of brain.
The suppressive activity on the mutation-inducing factors has been measured and 24-49% of suppression was observed. Also, blueberry extracts have shown inhibitory effects on the cells of cervical cancer and breast cancer which are the most prevalent cancers in women. The mechanism has been reported to be based on the inhibition of mutation caused by ‘methyl methansulfonate’, a well known carcinogen, and activity of benzopyrene which is activated by metabolism. Based on this mechanism, it eventually prevents cancers.
It has astringent effect and anti-diarrheal effect from the catechin tannin compound which is also effective in wound treatment. In some data, anthranconyoside of bilberry showed anti-bleeding effect and vascular-protective effect as well as anti-ulcer and anti-coagulant effect in the human blood.
In numerous animal experiments, anthocyanosides exhibited collagen-stabilizing effects and prevented ischemic vascular damages. Anthocyanides also decreased the synthesis of collagen polymers in diabetic patients effectively.
In vitro, it has inhibited the proliferation of encephalitis virus mediated by mites.
Since anthocyanin helps the insulin synthesis, it is effective in diabetes caused by the lack of insulin. As the only hormone lowering the blood glucose in the human body, it is generated by anthocyanin included in bilberry.
400mg of bilberry extracts were administered twice a day to 20 patients with diabetic retinopathy. As a result, the capillary resistance of the patients was increased to make a conclusion that the bilberry extracts prevent the bleeding of retina.
It Prevents skin cancer and colon cancer with anti-cancer effect, decreases abdominal fat, and treat stroke and myocardial infarction.
It prevents the platelet coagulation. Therefore, there is a possibility that it may interact with anti-coagulants such as aspirin and warfarin.
No side effect or risk factor has been known. High concentration of tannin may cause indigestion.