Protect Your Eyes With Vitamin C
By Dr. Mercola
By the age of 80, more than half of Americans have cataracts or have had cataract surgery.1 A cataract is a clouding of the lens in your eye that affects your vision, and although they can often be treated with surgery, cataracts remain the No. 1 cause of blindness worldwide.2
It’s quite telling that, according to the National Eye Institute (NEI), cataract removal is one of the most common operations performed in the U.S.
Your risk increases with age, and cataracts are often said to be a result of age, but just because they’re common does not mean they’re an inevitable part of getting older.
Recent research published in the journal Ophthalmology used data from 1,000 pairs of twins and found that while genetic factors explained 35 percent of the variation in cataract progression over a 10-year period, environmental factors accounted for the rest (which means they’re more influential than genetics).3
When vitamin C was removed from retinal cells, GABA-type receptors in the brain, which help modulate communication between brain cells, stopped functioning properly.
The researchers believe GABA receptors elsewhere in the brain likely also require vitamin C for proper functioning, and that the antioxidant properties of the vitamin may “preserve the receptors and cells from premature breakdown.”14
The finding could also have implications for people with glaucoma, which is caused by dysfunction of nerve cells in the retina and brain.
Von Gersdorff continued, “For example, maybe a vitamin C-rich diet could be neuroprotective for the retina — for people who are especially prone to glaucoma.”15
How Else Does Vitamin C Benefit Your Vision?
Vitamin C is concentrated in eye tissues, where it supports the health of blood vessels among other uses. In addition to helping to prevent cataracts, research suggests vitamin C may lower your risk of age-related macular degeneration (AMD), a common cause of blindness among the elderly.
Like cataracts, AMD is thought to be largely driven by free radical damage. The Age-Related Eye Disease Study (AREDS), sponsored by the National Eye Institute, linked AMD with nutrition. It found that those at high risk who took 500 mg per day of vitamin C, along with beta-carotene, vitamin E, and zinc, slowed the progression of advanced AMD by about 25 percent and visual acuity loss by 19 percent.16
The U.S. Food and Drug Administration (FDA) recommends only a modest amount of daily vitamin C—90 mg/day for men and 75 mg/day for women. You’ll likely need more than this for vision health.
For instance, one study found women who consumed 362 mg or more of vitamin C daily had a 57 percent lower risk of developing cataracts by age 60 than women consumed less than 140 mg per day.17 People under stress also require more vitamin C than normal. This includes:18
Bioflavonoids and Other Antioxidants for Vision Health
Vitamin C is just one type of antioxidant that benefits your vision. Others include bioflavonoids, which may have a complementary effect when taken along with vitamin C.
Fortunately, virtually every food that contains vitamin C also contains bioflavonoids, yet another reason why it’s best to get your nutrients from whole foods. Excellent dietary sources of bioflavonoids include dark-colored berries, dark leafy greens, garlic, and onions.
Further, according to the journal Nutrition Reviews, “Epidemiologic literature suggests that the risk of cataracts can be diminished by diets that are optimized for vitamin C, lutein/zeaxanthin, B vitamins, omega-3 fatty acids, multivitamins, and carbohydrates.”19 In short, other notable nutrients for vision health include:
Besides eating plenty of the nutrients above, carotenoids-rich vegetables, organic pastured egg yolks, omega-3 and astaxanthin-rich salmon are beneficial for vision health. Another really important dietary aspect is to normalize your blood sugar, as excessive sugar in your blood can pull fluid from the lens of your eye, affecting your ability to focus.
It can also damage the blood vessels in your retina, thereby obstructing blood flow. To keep your blood sugar in a healthy range, follow my comprehensive nutrition guidelines, avoid processed foods, as they tend to be loaded with processed fructose, and be sure to exercise regularly.
Sources and References
- Ophthalmology March 23, 2016
- Medical News Today March 24, 2016
- OHSU University July 14, 2011
- American Optometric Association, Vitamin C
- All About Vision
- Nutrition Express
- 1 National Eye Institute, Facts About Cataract
- 2 World Health Organization
- 3 Ophthalmology March 23, 2016
- 4 Medical News Today March 24, 2016
- 5 Am J Clin Nutr. 1997 Oct;66(4):911-6.
- 6, 8, 16, 18 American Optometric Association, Vitamin C
- 7 Linus Pauling Institute, Vitamin C
- 9 Am J Clin Nutr. 2010 Feb;91(2):487-93.
- 10 Am J Epidemiol. 2013 Mar 15;177(6):548-55.
- 11 FASEB J. 2010 Jan;24(1):158-72.
- 12 J Neurosci. 2011 Jun 29;31(26):9672-82.
- 13, 14, 15 OHSU University July 14, 2011
- 17 Am J Clin Nutr. 2002 Mar;75(3):540-9.
- 19 Nutr Rev. 2014 Jan;72(1):30-47
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