Bilberry (Vaccinium myrtillus ), the European blueberry, first caught the attention of the medical community during World War II, when British Royal Air Force pilots who snacked on bread and bilberry jam before their night missions started hitting their targets more often. Today, the fruit is widely used in Europe to relieve eyestrain.
What is it good for?
It may be good for your eyes. Researchers believe that bilberry may improve retinal lesions due to diabetic or hypertensive retinopathy. Others speculate that bilberry may help prevent disorders such as macular degeneration, cataracts, and glaucoma, all of which can rob you of your eyesight as you age. More research is needed in this area.
It was once thought that bilberry may help you see better at night. In one small French study, 14 out of 14 air traffic controllers reported better night vision after taking bilberry extract for about 15 days. However, more recent studies aren't so promising. In one Florida study, 15 young men were given high doses of bilberry for three weeks with no improvement in their night vision. The same results were found in an Israeli study of 18 volunteers. And in a 2004 review of placebo-controlled trials, researchers concluded that bilberry did not improve normal night vision.
How does it work?
Bilberries, along with blueberries and blackberries, get their deep blue color from anthocyanins, powerful antioxidants that protect cells from oxygen molecules called free radicals that can wreak havoc throughout the body. In particular, anthocyanins may improve vision by keeping the capillaries in the back of the eye from breaking down (macular degeneration) and the lens from clouding (cataracts). They may strengthen capillaries and improve circulation elsewhere as well, reducing hemorrhoids and varicose veins. The dried berries are used in Europe to treat diarrhea because they contain tannins, bitter compounds that reduce tissue inflammation, and pectin, a soluble fiber that adds bulk to the stool and soothes the gut.
How safe is it?
In Europe, bilberry extract is the active ingredient in a number of over-the-counter and prescription drugs; no toxic effects have ever been reported. However, its compounds can inhibit blood clotting, so don't use it if you're already taking medication to thin your blood. Remember, too, that impaired vision or eye disease of any kind is a serious condition and should be discussed with a medical professional. If you're considering using bilberry supplements or you're concerned about your vision, tell your doctor. It's also important to know that bilberry leaf and bilberry leaf extract is toxic in high doses. It's best to stick to the fruit, but if you take a supplement, be careful not to overdo it.
How is it taken?
You can buy concentrated extracts of bilberry fruit and skin in capsule form in pharmacies and health food stores. Keep in mind that the government doesn't regulate dietary supplements as strictly as it does other drugs, so quality and potency can vary from bottle to bottle. In rare cases, these products may be contaminated with undesirable substances. Most preparations claim to contain 25 percent anthocyanins, but since researchers don't know exactly how the body uses these chemicals, there's no guarantee that purified extracts offer all the benefits. If you can get them, you might do better just to throw a handful of blueberries over your cereal in the morning; fresh blueberries are likely to deliver a richer mix of antioxidants.
Zadok D, et al; The effect of anthocyanosides in a multiple oral dose on night vision. Eye 1999 Dec;13(Pt 6):734-6.
Muth ER, et al; The effect of bilberry nutritional supplementation on night visual acuity and contrast sensitivity. Altern Med REv 2000 Apr;5(2):164-73.
Canter P. et al. Anthocyanosides of Vaccinium myrtillus (bilberry) for night vision--a systematic review of placebo-controlled trials. Survey of Opthamology. 49(1):38-50. 2004.
National Center for Complimentary and Alternative Medicines. Bilberry. May 2006.