What Is a “Healthy Diet” for Good Vision?
According to the Dietary Guidelines for Americans developed by the U.S. Department of Health and Human Services and the Department of Agriculture, a healthful diet:
A diet containing plenty of fruits and vegetables can help you enjoy a lifetime of good vision.
Emphasizes fruits, vegetables, whole grains and fat-free or low-fat milk and milk products, and almond milk.
Includes lean meats, poultry, fish, beans, eggs and nuts.
Is low in saturated fats, trans fats, cholesterol, salt (sodium) and added sugars.
But it’s common knowledge that most Americans don’t eat enough fruits, vegetables and other nutrient-rich foods, opting instead for high-calorie, low-nutrient alternatives that can be harmful to the body, including the eyes.
Taking a daily multivitamin and mineral supplement can help fill in the nutritional gaps in a less-than-optimal diet and may help protect you from degenerative diseases, including eye diseases such as macular degeneration and cataracts
AREDS and AREDS2 – Eye Supplements and Age-Related Eye Disease
Two of the most influential studies of the benefits of eye supplements are the AREDS and AREDS2 studies sponsored by the National Eye Institute. (AREDS is an acronym for “Age-Related Eye Disease Study.”)
Each of these multicenter U.S. clinical trials enrolled several thousand participants and had a follow-up period of at least five years.
AREDS. The original AREDS study investigated the effect of use of a daily multivitamin supplement on the development and progression of AMD and cataracts in a population of approximately 3,600 participants, ages 55 to 80.
Most of the study participants already had early or intermediate AMD at the time of enrollment, and the average follow-up period of the study was 6.5 years. The multivitamin supplement contained beta-carotene (15 mg), vitamin C (250 mg), vitamin E (400 IU), zinc (80 mg) and copper (2 mg).
Eye supplements can help fill in nutritional gaps in a less-than-perfect diet.
Results of the original AREDS were published in 2001 and showed that the antioxidant multivitamin used in the study reduced the risk of AMD progression to advanced stages among people at high risk of vision loss from macular degeneration by about 25 percent.
Also, in the same high-risk group that included participants with intermediate AMD, or advanced AMD in one eye but not the other, the daily multivitamin reduced the risk of vision loss caused by advanced AMD by about 19 percent.
For study participants who had either no AMD or only early AMD, the multivitamin provided no apparent vision benefits. Also, the daily eye supplement had no significant effect on the development or progression of cataract among study participants.
AREDS2. AREDS2 was designed to investigate the effect of modifications of the original AREDS supplement formula on the development and progression of AMD and cataracts.
In particular, lutein and zeaxanthin — plant pigments (carotenoids) that other research suggests may have eye benefits — and omega-3 fatty acids were evaluated.
Also, AREDS2 researchers wanted to evaluate a modification of the original AREDS multivitamin formulation because some research has linked beta-carotene supplementation to increased risk of lung cancer in smokers and previous smokers, and because of concerns about minor side effects such as stomach upset caused by the high amount of zinc in the original AREDS formula among some people.
Results of the AREDS2 study were published in May 2013. Participants in the study who took an AREDS formulation that included lutein and zeaxanthin, but no beta-carotene, had an 18 percent lower risk of developing advanced AMD over the five years of the study, compared with participants who took the original AREDS formulation with beta-carotene.
Also, AREDS2 participants with low dietary intake of lutein and zeaxanthin at the start of the study were up to 25 percent less likely to develop advanced AMD when taking a daily multivitamin that included 10 mg lutein and 2 mg zeaxanthin, compared with participants with similar dietary intake who did not take a supplement containing lutein and zeaxanthin during the study.
None of the modified AREDS supplement formulations used in AREDS2 — including those containing 1,000 mg omega-3 fatty acids (350 mg DHA and 650 mg EPA) — prevented or reduced the risk of cataracts.
Recommended Ingredients in Vision Supplements
As research continues on the benefits of vision supplements in reducing the risk of eye problems (and perhaps in improving visual acuity in healthy eyes), it seems wise to supplement your diet with a daily eye supplement that contains many, if not all, of the following ingredients.
Most of these vitamins and nutrients may play a key role in reducing inflammation and oxidative changes associated with the development of degenerative diseases, including chronic and age-related eye problems:
Vitamin A and beta-carotene. Vitamin A (and its precursor, beta-carotene) is necessary for night vision, wound healing and proper functioning of the immune system. Though supplemental beta-carotene has been associated with greater risk of certain cancers among smokers and previous smokers, obtaining a healthy amount of beta-carotene from natural food sources does not appear to elevate this risk.
Vitamin B complex (including vitamins B1, B2, B3, B5, B6, B12 folic acid, biotin and choline). B complex vitamins may help reduce chronic inflammation and prevent elevated homocysteine levels in the blood, which have been associated with vascular problems affecting the retina. B vitamins also may play a role in reducing the risk of macular degeneration and in the treatment of uveitis, a common cause of blindness.
Vitamin C. Some studies have found vitamin C, a powerful antioxidant, is associated with reduced risk of cataracts.
Vitamin D. Recent literature suggests vitamin D deficiency is widespread, especially during winter months in cold climates. Research suggests vitamin D is associated with a lower risk of macular degeneration.
Vitamin E. Another component of AREDS and AREDS2 supplements, vitamin E has been associated with reduced risk of cataracts in other studies.
Lutein and zeaxanthin. These carotenoids and macular pigments may reduce the risk of macular degeneration and cataracts.
Phytochemical antioxidants. Plant extracts, such as those from ginkgo biloba and bilberry, contain phytochemicals, which appear to provide protection from oxidative stress in the entire body, including the eyes.
Omega-3 essential fatty acids. These essential nutrients may reduce the risk of dry eyes and may have other eye health benefits as well.
Bioflavonoids. Found in many fruits and vegetables, bioflavonoids appear to help the body absorb vitamin C for higher antioxidant efficiency.
Bilberry Lutein and Zeaxanthin in pro- healing complex form.
Vision Support Ocubright
Bilberry Extract (Vaccinium myrtillus)
The applicable parts of bilberry are the fruit and leaf. Astringent tannin components of bilberry dried, ripe fruit are responsible for the potential benefits in diarrhea and irritation of the mouth and throat mucosa. Anthocyanadin (anthocyanoside) constituents increase the synthesis of glycosaminoglycans, decrease vascular permeability, reduce basement membrane thickness, and aid in the redistribution of microvascular blood flow and the formation of interstitial fluid. An anthocyanadin pigment found in bilberry fruit might have anti-ulcer and gastroprotective effects. Preliminary evidence indicates these constituents are widely distributed in the body after oral administration and are eliminated by the kidneys. Laboratory research also suggests that anthocyanadins have anti-inflammatory and anti-edema effects.
Bilberry leaves contain polyphenols, tannins, flavonoids and a relatively high concentration of chromium (9.0 ppm). Preliminary evidence suggests that a bilberry leaf extract might have blood glucose, triglyceride, and cholesterol lowering effects. The chromium in bilberry leaf is theorized to play a role in potential blood glucose lowering activity. Bilberry leaf also contains a glucokinin, neomirtilline that seems to lower blood glucose. Some researchers think that flavonoids in bilberry leaf might also be useful for diabetic circulatory disorders.
Lutein and Zeaxanthin
Lutein is a carotenoid that is typically found in combination with its stereoisomer, zeaxanthin. Lutein makes up about 11% of the total carotenoids in serum and about 20% of the carotenoids in adipose tissue. Serum and adipose tissue levels are affected by dietary intake. Lutein levels in breast adipose tissue seem to be affected by diet, which could explain the lower incidence of breast cancer with increased fruit and vegetable intake. Additionally, there is some evidence of an inverse association between serum lutein levels and breast cancer risk. Lutein and zeaxanthin are the two major carotenoid pigments in the human macula and retina. They are thought to function as antioxidants and as blue light filters, protecting underlying ocular tissues from photodamage.
Epidemiological evidence has associated high dietary lutein intake with reduced risk of developing age-related macular degeneration (AMD) and cataracts. Increasing dietary lutein intake increases serum lutein levels and macular pigment density. Low dietary lutein intake is associated with males, smokers, and people who drink alcohol (more than 2 drinks per week); while higher dietary lutein intake is associated with females, increasing age, and people with hypertension. Foods containing high concentrations of lutein such as broccoli, spinach, and kale, are associated with the greatest eye health benefits. Other carotenoids and antioxidants such as vitamin A, lycopene, alpha- or beta-carotene, vitamin C, and vitamin E have not been associated with this benefit. Epidemiologic studies have shown that carotenoids might be inversely associated with cancer.
There are epidemiological studies that suggest a reduced risk of developing severe cataracts that require surgical removal in people consuming higher amounts of lutein in their diet. It is not known if supplemental lutein offers the same benefit. There is epidemiological evidence that suggests a reduced risk of developing colon cancer in people consuming higher amounts of lutein in their diet. It is not known if supplemental lutein offers the same benefit.
Actions and Indications
Age-related macular degeneration (AMD): Taking zinc orally in combination with antioxidant vitamins might slow the progression of advanced age-related macular degeneration (AMD). Elemental zinc 80 mg plus vitamin C 500 mg, vitamin E 400 IU, and beta-carotene 15 mg daily seems to provide a risk reduction of 27% for visual acuity loss and a risk reduction of 24% for progression of AMD in patients with advanced AMD. Patients with monocular or binocular intermediate AMD or monocular advanced AMD are at high risk for advanced AMD. Theoretically, these patients may also benefit from zinc and antioxidant supplementation. There isn’t enough information to determine if zinc plus antioxidants is beneficial for people with less advanced macular disease or for preventing AMD. However, dietary zinc or zinc supplementation alone does not seem to reduce the risk of developing of AMD. There is some epidemiological evidence that people who consume higher amounts of lutein in their diet have a reduced risk of developing AMD. Preliminary clinical research suggests that taking lutein supplements 10 mg per day for 12 months can improve some symptoms of AMD such as macular pigment optical density and glare recovery, near vision acuity, and contrast sensitivity. But lutein supplements don’t seem to affect the progression of AMD. It’s not known whether lutein supplements can decrease the risk of AMD as effectively as dietary lutein.
The amino acid found naturally in egg whites, meat, fish, and milk. High concentrations are found in the heart muscle, white blood cells, skeletal muscle, and central nervous system. In the retina there are two binding proteins specific to taurine. Intracellular concentrations are higher in the retina than in any other region derived from the central nervous system, helps to protect the cell membranes from oxidative attack. It helps transport nutrients across cell membranes, acts as a catalyst to retinal cells that remove cellular debris and assists in the elimination of potentially toxic substances.
Taurine plays a role in the process of rhodopsin regeneration necessary for night vision. It is essential to the retinal pigment epithelium and the photoreceptors where it is found at levels ten times higher than other amino acids. Taurine helps to protect the cell membranes from oxidative attack. It helps transport nutrients across cell membranes, acts as a catalyst to retinal cells that remove cellular debris and assists in the elimination of potentially toxic substances. Taurine a non-essential Sulfurous Amino Acid, also protects the rod outer segment lipids during exposure to cyclic light, protect the eyes from UV light and helps strengthen the retinal cells. It functions independently within the body (i.e. it is not incorporated into Proteins). It is manufactured endogenously within the Liver from Cysteine and Methionine.
Several studies have shown definite correlations between taurine deficiency and retinal degenerations. Taurine deficiency is often associated with an imbalance of intestinal flora, commonly called “leaky gut” and inhibits taurine absorption. Taurine levels can also be lowered by overgrowth of candida, physical or emotional stress, and excessive consumption of alcohol. The drugs like tranquilizers and anti-inflammatory agents also inhibit the uptake of taurine and have been known to cause retinal damage with prolonged or excessive dosage. Taurine is a crucial amino acid for the brain as it helps generate nerve impulses.
Taurine is found in high concentrations in the eye and is the most plentiful amino acid in the retina of all animal species. Taurine has multiple functions to maintain normal retinal structure and function. Decreased taurine levels in the eyes are linked to the disease retinitis pigmentosa. Depletion of taurine leads to degeneration of the photoreceptor cells. Taurine may help to prevent and reverse Age-Related Macular Degeneration (ARMD) (Taurine concentrates in the Macula of the Retina, where it exerts Antioxidant effects that may counteract ARMD). Taurine may help to prevent (and may also possibly reverse) Cataracts by inhibiting the glycosylation process in the Lens of the Eye that is an underlying cause of Cataracts. Taurine may alleviate the Eye Fatigue caused from working with Visual Display Terminals. Taurine concentrates in the Macula. Retinitis Pigmentosa may occur as a result of Taurine deficiency. Taurine may help to prevent (diabetic) Retinopathy. Taurine enhances the function of the Rods and Cones of the Retina, making it essential for optimal Sight. Taurine deficiency can cause degeneration of the Retina.
Zinc is a biologically essential trace element and is the second most abundant trace element in the body. The total body content is about 2 grams (1). It is a cofactor in many biological processes including DNA, RNA, and protein synthesis. About 30% of cellular zinc is found within the nucleus. A large number of proteins that play a role in the regulation of gene expression are thought to contain zinc (2). Zinc also plays a role in immune function, wound healing, reproduction, growth and development, behavior and learning, taste and smell, blood clotting, thyroid hormone function, and insulin action (3). Zinc is found in more than 300 enzymes (2).
Nearly 100 enzymes depend on zinc as a catalyst (4). Zinc is also required in hepatic synthesis of retinol binding protein, the transport protein of vitamin A (5). Without adequate zinc, symptoms of vitamin A deficiency can appear, despite vitamin A supplementation (5). There are many other important roles that zinc plays in the human body, but one of the most important roles it plays is a key role in the maintenance of vision. It is present in high concentrations in the eye, particularly in the retina and choroid. Zinc deficiency can alter vision, and severe deficiency causes changes in the retina and retinal pigment epithelium (RPE). Zinc interacts with taurine and vitamin A in the retina, modifies plasma membranes in the photoreceptors, regulates the light-rhodopsin reaction within the photoreceptor, modulates synaptic transmission, and serves as an antioxidant in both the RPE and retina. It seems to slow the progression of some degenerative retinal diseases (1). Topically, zinc sulfate ophthalmic solution acts as a mild astringent, precipitating protein and clearing mucus from the outer surface of the eye (6).
Taking zinc orally in combination with antioxidant vitamins doesn’t seem to help treat or prevent cataracts. Taking elemental zinc 80 mg plus vitamin C 500 mg, vitamin E 400 IU, and beta-carotene 15 mg daily does not seem to have any effect on the development or progression of age-related lens opacities (cataracts) or the need for cataract surgery in well-nourished people 55-80 years of age. However, it is unknown whether earlier intervention and/or a longer period of treatment with supplements would have any effect on cataracts (7).
Copper is an essential trace mineral. It is widely distributed in foods particularly in organ meats, seafood, nuts, seeds, wheat bran cereals, grain products, and cocoa products (4). Absorption occurs primarily in the small intestine with lesser absorption in the stomach (4). The majority of copper in the body is in the skeleton and muscles; the liver maintains plasma copper concentrations. Excretion of copper into the gastrointestinal tract regulates copper homeostasis; greater excretion is the result of increased absorption (4).
Large amounts of zinc can inhibit copper absorption, due to competition for absorption from the gut (8,9,10), which is why attention must be paid to both minerals and is the reason for the addition of a small amount of copper in Ocubright.