Is This Deficiency Causing Your Vision to Slip?
As you read this, you are relying on the health of your eyes. Many people neglect to consider the impact of nutrition on vision health, but the connection is undeniable: What you eat affects how well you see later in life. And according to a recent study review, the connection is even stronger than we thought.
It is certainly no secret that fruits and vegetables are good for you. They have been shown to reduce your risk for diabetes, Alzheimer’s disease, heart disease and even cancer. And a diet high in fresh, organic produce paired with natural sources of omega-3 fatty acids also keeps your waistline trim and your skin fresh and radiant. But generally speaking most people fail to get the full spectrum of antioxidants required to adequately protect their eyesight.
Antioxidants and Cataracts: Are You Getting the Right Ones to Protect Your Vision?
It has long been established that a primary factor in the development of cataracts is oxidative damage to the lens. For this reason, much of the research surrounding nutrition and cataracts includes the use of antioxidants.
Lutein and zeaxanthin, two powerful and highly underestimated antioxidants, seem to play a key role in protecting against cataracts. One study found that a higher intake of foods containing these two nutrients was associated with a reduced likelihood of developing cataracts. In the Nurses’ Health Study researchers found that women who had higher daily intakes of lutein and zeaxanthin had a 22 percent reduction in cataract risk.
The researchers also found that women who took a vitamin C supplement for 10 years or more had significantly lower incidence of cataracts. This same study found that women who used vitamin E supplements for five years also enjoyed reduced progression of cataracts. Similarly, the Beaver Dam Eye study found that people who used a multivitamin that contained vitamins C or E for more than 10 years had a 60 percent lower likelihood of developing cataracts.
Antioxidants and Age-Related Macular Degeneration
To help determine if certain foods and supplements could impact the treatment or prevention of eye disease, researchers focused their attention on the two most common conditions: age-related macular degeneration (AMD) and cataracts.
Starting with AMD, researchers looked at two key studies: the Age-Related Eye Disease Study (AREDS) and AREDS2.
Age-Related Eye Disease Study (AREDS 1)
In AREDS, researchers studied the impact of five key nutrients on eye health:
* Vitamin C (500 mg)
* Vitamin E (400 IU as alpha tocopherol)
* Beta-carotene (15 mg)
* Zinc (80 mg)
* Copper (2 mg)
Vitamin C is highly concentrated in your eye’s lens, while vitamin E protects against oxidation (“rusting” if you will) and free radical damage. Additionally, higher intakes of vitamin E have been found to increase concentrations within the retina.
Beta-carotene also helps prevent oxidation, while zinc has been tied to many enzymatic metabolic functions within the retina. This likely explains its high concentrations within the retina itself. Lastly, the addition of copper is needed to offset the copper depletion that can happen with increased zinc.
AREDS found that these nutrients lowered the risk for AMD in those patients at the greatest risk for developing the disease. Additionally, a study performed in the Netherlands found that people taking above average dietary intake of the AREDS nutrients had a 56 percent reduced risk of AMD, while those with below average intake had a 33 percent increased risk.
Age-Related Eye Disease Study (AREDS 2)
With AREDS2, researchers created a five-year, multicenter, randomized trial of nearly 4,000 participants between the ages of 50 and 85. The study began in 2008 and focused on four key nutrients:
* Lutein (10 mg)
* Zeaxanthin (2 mg)
* DHA (350 mg)
* EPA (650)
Both lutein and zeaxanthin are carotenoids found in colorful fruits and vegetables, namely yellow and orange foods, as well as leafy green veggies. DHA and EPA are both omega-3 fatty acids found primarily in cold-water fish.
Lutein and zeaxanthin have long been known to help prevent AMD, especially when those nutrients are consumed in the form of foods such as broccoli and other cruciferous vegetables. Other additional studies have shown that lutein in particular helps to improve macular pigment density, as well as significantly improve visual acuity and retinal function. It also helped to slow the progression of AMD.
When it comes to DHA and EPA, these omega-3 fatty acids help to reduce inflammation and regulate the genetic expression of retinal cells. However, of the two omega-3s, DHA seems to play the bigger role in eye health.
There is significant concentration of DHA is both the brain and retina cells’ membranes. If fact, it is the most abundant omega-3 fatty acid in the macula (the center part of the retina), as well as the periphery of the retina.
When it comes to omega-3s overall, studies have shown that these polyunsaturated fatty acids reduce the risk of AMD by up to 38 percent when taken in high amounts, either as supplements or fish. Other studies have shown that eating fish at least once a week was associated with a 40 percent reduction in age-related maculopathy.
What’s really interesting is that a fairly recent study found that DHA supplementation alone increased the density of central macular pigment, while lutein alone increased macular pigment density around the fovea (the center of the macula). When taken in combination, increases were seen in both areas.
Lastly, researchers have found that B vitamins and vitamin D also help prevent AMD. With B vitamins, long-term, daily use of 2.5 mg of folic acid, 50 mg of vitamin B6, and 1 mg of vitamin B12 reduced the risk of mild AMD by 40 percent. Similarly, 604 IU of vitamin D (from both food and supplements) reduced risk of early AMD.
Protect Your Eyes Naturally
Given these promising results, there are several simple and delicious things you can do to protect your vision.
On the diet front:
* Eat the rainbow. Focus on yellow and orange fruits and vegetables, as well as leafy greens and cruciferous veggies like broccoli and Brussels sprouts.
* Dig into eggs. The yolks are rich in lutein.
* Think seafood. Aim for at least two to three servings of wild-caught, cold-water fish per week.
* Enjoy citrus fruits and berries. These are great sources of vitamin C.
* Go Nuts. Nuts and seeds are good sources of vitamin E.
On the supplement front:
* Folate (up to 2.5 mg)
* Vitamin B6 (up to 2.2 mg)
* Vitamin B12 (up to 1 mg)
* Vitamin C (360 to 500 mg)
* Vitamin E (400 IU)
* Vitamin D3 (600 IU)
* Beta-carotene (up to 15 mg)
* Lutein (10 to 15 mg)
* Zeaxanthin (2 mg)
* DHA and EPA (1,000 mg combined)
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Kimberly Day has spent the past 15 years uncovering natural and alternative health solutions. She was the managing editor for several of the world’s largest health newsletters including those from Dr. Susan Lark, Dr. Julian Whittaker and Dr. Stephen Sinatra. She has also penned several health-related newsletter and magazine articles, co-authored the book the Hormone Revolution with Dr. Susan Lark, contributed articles to Lance Armstrong’s consumer site livestrong.com, and created a number of health-related websites and blogs.
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