By Kimberly Beauchamp, ND
Healthnotes Newswire (November 10, 2005)—Supplementing with a highly concentrated extract of bilberry fruit (Vaccinium myrtillus) may help improve night vision in nearsighted people, reports the British Journal of Nutrition (2005;93:895–9).
Bilberry, a relative of the blueberry, is a small shrub that grows in northern Europe and North America. Historically the berries have been used to treat diarrhea, hemorrhoids, and urinary tract infections. The active components of bilberry, called anthocyanosides, are potent antioxidants, which help repair tissue and strengthen blood vessels. Preliminary studies have shown that bilberry may prevent cataracts and help treat age-related macular degeneration and the eye damage that occurs in some people with diabetes (diabetic retinopathy). Anthocyanosides also enhance the function of a compound in the eye that is responsible for night vision. British World War II pilots reported improved night vision after eating bilberries. Not all studies, however, have concluded that bilberry has vision-enhancing effects.
Nearsightedness, or myopia, affects up to 30% of Americans. The condition occurs when the eyeball is too long from front to back, causing light rays to be focused too far forward within the eye. People with myopia can see nearby objects clearly, but objects in the distance appear blurry. Nearsightedness can also cause eye strain that may contribute to headaches, dryness of the eyes, decreased night vision, and eye discomfort when reading or in bright light.
The new study was conducted to determine the effect of a bilberry extract on night vision and other symptoms related to nearsightedness in 60 people with mild to moderate myopia. People received either 100 mg of a bilberry extract (containing 85% anthocyanosides) two times per day or a placebo for four weeks. Contrast sensitivity, a measure of nocturnal visual function, was tested before and after treatment. The participants also answered questions regarding the frequency and severity of their eye symptoms including eye strain, dryness, tearing, blurry vision, and decreased vision in dark places.
The bilberry-supplemented group showed significantly greater improvement in eye symptoms than the placebo group. Contrast sensitivity was also significantly improved in the bilberry group, suggesting an improvement in night vision. No improvement in night vision was seen in the placebo group. No side effects were associated with use of the bilberry supplement.
This study provides convincing evidence that bilberry may help improve night vision in people with myopia. Previous trials that included healthy people found no effect of bilberry on night vision; however, these studies used bilberry preparations with much lower concentrations of anthocyanosides (5 to 30%) given for shorter periods of time. Vitamin A and zinc may also help improve night vision in people who don’t eat or drink adequate amounts of these nutrients.
Kimberly Beauchamp, ND, earned her bachelor’s degree from the University of Rhode Island and her Doctorate of Naturopathic Medicine from Bastyr University in Kenmore, WA. She cofounded South County Naturopaths in Wakefield, RI. Dr. Beauchamp practices as a birth doula and lectures on topics including whole-foods nutrition, detoxification, and women’s health.
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