Thursday, March 26, 2015

Essential Eye Nutrients

Food and lifestyle choices can influence your eye health and may help to reduce the risk of some age-related eye diseases.  Check out this quick summary of the nutrients essential for good eye health.
*Disclaimer: I am not a nutritionist or a dietician.
  • Zinc (red meat, poultry, oysters, beans, fortified cereal)
    • The Food and Nutrition Board recommends: 11 mg/day for males, 8 mg/day for females
    • Zinc is an essential mineral that is involved in cell metabolism.  It is highly concentrated in the retina and choroid of the eye.
  • Vitamin E (nuts, seeds, vegetable oils)
    • The Food and Nutrition Board recommends: 15 mg or 22.4 IU/day for both males and females
    • Vitamin E is a powerful antioxidant that is involved in immune function.
  • Vitamin C (citrus, strawberries, broccoli, red and green pepper, kiwi)
    • The Food and Nutrition Board recommends: 90 mg/day for males, 75 mg/day for females
    • Vitamin C is an antioxidant that helps absorb UV radiation. It is found in high concentrations in the lens, aqueous humor, and vitreous humor of the eye.  On a long term basis, increased intake of vitamin C (alone or in combination with other antioxidants) has been shown in some studies to reduce the risk of developing nuclear sclerotic cataracts (12).

    The National Eye Institute's Age-Related Eye Disease Study (AREDS) found that daily intake of 80 mg zinc, 2 mg copper, 500 mg vitamin C, 15 mg beta carotene, and 400 IU vitamin E could reduce the risk of progression to advanced Age-related Macular Degeneration (AMD) by about 25% and visual acuity loss by 19% in individuals at high risk for the disease (3).  Since that study, researchers have found that substituting beta carotene with 10 mg lutein and 2 mg zeaxanthin is safer and more effective (4).
    • Vitamin A (beef liver, carrot, pumpkin, sweet potato)
      • The Food and Nutrition Board recommends: 900 micrograms or 3000 IU/day for males, 700 micrograms or 2300 IU/day for females
      • Vitamin A is essential in the proper functioning of the retina, as well as the conjunctival membrane and cornea.  Most Americans get sufficient vitamin A from their diet, but vitamin A deficiency (VAD) is actually the leading cause of preventable blindness in children world-wide (5).
    • Lutein (kale, spinach, collards, egg yolks)Zeaxanthin (gogi berries, orange peppers, corn)
      • The American Optometric Association recommends: 10mg/day of lutein and 2mg/day of zeaxanthin
      • Lutein and zeaxanthin are carotenoids that are abundant in the macula of the eye as well as the lens. They are antioxidants that help lower your risk for Age-related Macular Degeneration (AMD) and cataracts.
      From Review of Optometry
      A follow-up to AREDS- AREDS 2- found that people with the lowest dietary levels of lutein and zeaxanthin who added supplements of the two had a 26% reduced risk of developing advanced AMD.  Those with the lowest dietary intake of lutein and zeaxanthin also saw a 32% risk reduction in progression to cataract surgery with the introduction of these nutrients (6).  Most Americans only get 1-2 mg of lutein and zeaxanthin combined on a daily basis through their diet, so many of us fall into this category.

      Fun Facts: Vitamins A, D, E, and K, as well as lutein and zeaxanthin, are fat-soluble.  A small amount of dietary fat (ie: olive oil, avocado, nuts, seeds) can help maximize the body's absorption of these nutrients.  Cooking (steaming, sautéing, or puréeing) leafy greens actually allows more access to the important nutrients by breaking down plant cell walls.

      • Omega-3 Fatty Acids (wild salmon, mackerel, tuna, sardines)
        • The American Heart Association recommends eating at least two servings of fish (especially oily fish)/week
        • The 3 types of omega-3 fatty acids the body uses are ALA, DHA, and EPA.  DHA and EPA have structural and protective functions in the retina, and they also have anti-inflammatory properties.  Beyond the cardiovascular health benefits, diets rich in DHA and EPA have been linked to a significant improvement in dry eye symptoms (89)

      Eye vitamins and other supplements can help you meet your recommended daily intake of these nutrients. Be sure to discuss this with your optometrist or ophthalmologist.  I also recommend communicating with your primary care doctor before beginning any supplementation regimen- it's important to give your PCP the full picture of what you do to manage your health.

      If you want to find an optometrist that specializes in ocular nutrition, look here.

      CliffsNotes: What you eat can influence your eye health and may help to reduce the risk of age-related eye diseases.  

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