CATARACTS
Lens Metabolism Support
Bioflavonoids
Bioflavonoids are powerful inhibitors of the enzyme aldose reductase.68 If aldose reductase activity falls, sorbitol is not synthesized. This reduces the accumulation of water in the lens.86 The bioflavonoids quercetin, myrcetin, and kaempferol (from limes) specifically inhibit diabetic cataracts.71 Gingko is a widely used flavonoid that maintains microcirculation to the eye and inhibits free radicals.87 A suggested dose of gingko biloba is 120 mg daily.
Inositol
Inositol nicotinate is a B vitamin that occurs in high concentrations in the lens. Inositol exhibits antioxidant property resulting in the quenching of reactive oxygen and scavenging of glucose.88 Inositol works best taken with B complex vitamins. A suggested dose of inositol is 250 mg daily.89
Carnosine
Carnosine inhibits formation of advanced glycation end products (AGEs) and protects normal proteins from the toxic effects of existing AGEs.90,91 Eye drops containing N-acetyl-L-carnosine can delay vision senescence in humans: effective in 100% of primary senile cataract cases and 80% of mature senile cataract cases. N-acetyl-L-carnosine enter the aqueous and lipid parts of the eye and prevent and repair light-induced breaks to DNA strands.92 N-acetyl-L-carnosine eye drops are approved for human use in Russia for the treatment of many eye diseases. Brite Eyes II is an advanced eye formula that contains 1% N-acetyl-L-carnosine in a soothing eye drop. A suggested oral dose of carnosine is 500-1000 mg daily.
Ocular Environment Support
Carotenoids
Carotenoids are fat-soluble, yellowish pigments found in some plants, algae, and photosynthetic bacteria. Carotenoids are light-gathering pigments that provide protection from the toxic effects of oxygen free radicals and singlet oxygen which are generated in the presence of light and oxygen.93 Lutein and zeaxanthin are carotenoids found in high concentrations in the macula of the retina.94,95 Lutein and zeaxanthin protect the eye from age-related macular degeneration and cataract formation.65 Lutein is derived from dark green leafy vegetables (spinach, broccoli, kale, and collard greens). Zeaxanthin is found in yellow fruits and vegetables (corn, peaches, and mangoes). Suggested doses are 5 mg of zeaxanthin and 10 mg of lutein.
Coenzyme Q10
Coenzyme Q10 (CoQ10) is an antioxidant that provides protection from free radical damage in the eye.96 A combination of antioxidants including CoQ10, acetyl-L-carnitine, polyunsaturated fatty acids (PUFAs), and vitamin E improved mitochondrial function (linked to age-related macular degeneration) in retinal pigment epithelium.83 Mitochondrial dysfunction in lens epithelial cells and superficial fiber cells of the eye may lead to oxidative stress and cataract formation. Mitochondrial dysfunction occurs throughout the body and produces damaging reactive oxygen species thought to cause aging and disease.97 A suggested dose of CoQ10 is 100-200 mg daily.
Potassium and Magnesium
A lens with cataracts has decreased concentrations of potassium and magnesium.98 Potassium and magnesium are often deficient in aging humans. Supplementation with 400 mg of elemental potassium and 800 mg of elemental magnesium increases availability of these minerals to the lens and protects the arterial system.98
Gingko and Bilberry
Gingko biloba extract is an antioxidant, increases circulation to the optic nerve75 and has exhibit potential anti-cataract ability.87 Bilberry (from Vaccinium myrtillus fructus) is a proanthocyanidin historically used for eye conditions, including glaucoma, cataracts, macular degeneration, diabetic retinopathy, and retinitis pigmentosa.75 Gingko biloba and bilberry may restore microcapillary circulation.83 Suggested doses are Gingko biloba, 120 mg daily, and bilberry, 100 mg daily. After taking Ginkgo and bilberry for a month; taking 400 mcg of selenium, 500 mg of glutathione, and 300 mg of alpha-lipoic acid daily has been suggested. Note: See Appendix For Cautions and Contraindications.
FUNCTIONAL AND PRACTICAL MEDICINE
Overview
Treatment for cataracts is reactive: when cataracts adversely impact vision, they are surgically removed and replaced with an implanted lens. Cataract surgery is very effective and has a high success rate. Nutritional therapy can prevent the onset of cataracts, particularly because proven anti-cataract drugs are not available.62
Intervention strategies should address the underlying causes of cataracts: oxidative stress, free radical production, the breakdown and aggregation of lens proteins, dysfunction of metabolism in the lens, and inability to maintain a healthy ocular environment. Nutritional therapy is available for each of these underlying causes.
Free Radical Reduction
Metabolic Changes and Cataract
An aging lens undergoes metabolic changes that predispose it to cataracts. Some metabolic changes occur from reduced oxygen and nutrient supply which increases eye vulnerability to free-radical damage. The eye is protected by cellular antioxidants: glutathione and vitamin C. Healthy eyes are protected from free radical damage by a mechanism that produces and recycles antioxidants in the eye that neutralize free radicals. Cataract formation is associated with a breakdown in the mechanism that regulates utilization of glutathione and vitamin C and/or decreases their concentration in the lens and surrounding structures.58
Hydrogen Peroxide and Cataract
Cataract formation is initiated by the free radical hydrogen peroxide found in the aqueous humor.99 Hydrogen peroxide oxidizes glutathione, or conversely, glutathione chemically reduces hydrogen peroxide, ultimately damaging the energy-producing system of the eye and allowing sodium to leak into the lens. Excess sodium attracts water to maintain osmolality, which initiates the edema phase of a cataract. Normal body heat in the lens catalyzes oxidation of the lens’ proteins, which become opaque and insoluble (similar to the process by which egg protein changes from clear to opaque upon cooking). Free radicals break down fatty acids in membranes and lens protein fibers, generating more free radicals. This cross-links (or denatures or breaks down) the laminate-like structural proteins inside the lens capsule. The lens capsule can swell or shrink (dehydrate) and these changes in pressure breaks lens fiber membranes, forming microscopic spaces that trap water and debris.101
Metabolism Support: Key Components
The key components are glutathione and vitamin C. In particular, glutathione is required to protect mature lens fiber cells from free radical damage. Vitamin C (ascorbic acid) protects the lens from oxidative damage.99,100
Protection from Free Radicals: The Glutathione Mechanism
Nutritional supplements reduce the risks of developing cataracts and slow or reverse cataract growth.101 Blood circulation within the eye is minimal so supplementing with oral nutrients is challenging.102 The most important nutrients maintain or stimulate antioxidant mechanisms utilizing glutathione and include vitamins C, B2, E, selenium, alpha lipoic acid, melatonin, N-acetyl-cysteine with garlic, and glutathione. Decreased glutathione and vitamin C are associated with cataracts.103,104
Lens Protein Protection and Cellular Metabolism Maintenance
Proteins deep in the lens are generated during embryogenesis and must retain functionality for many decades. The inability to maintain protein stability over time leads to formation of a nuclear cataract (the predominant form). Once the lens forms (embryologically), proteins are only synthesized in the outermost fiber cells close to the lens surface.79 Accumulated damage to the proteins causes loss of enzymatic activity and increases the likelihood of protein aggregation, a component of cataract formation.20
The glycation (glycosylation) process can change (denature) lens proteins and significantly contribute to diabetic cataract formation and retinopathy. Glycation occurs when proteins react with sugars and form advanced glycation end products (AGEs), essentially, proteins strongly (covalently) bind to sugars, compromising the function of that protein. AGEs are biochemically altered proteins, DNA, and lipids with altered physiological properties.105
Nutritional supplements that may decrease breakdown of lens proteins and help maintain cellular metabolism include vitamin B6, acetyl-L-carnitine, aminoguanidine, bioflavonoids, inositol, and carnosine.
Maintaining a Healthy Ocular Environment
Cataract formation is connected to the aging process, associated with increased oxidative stress, and a consequence of free radical attacks, and reduced efficiency of metabolic processes. The lens provides an environment where these processes proliferate at a rate faster than that in other parts of the body. The lens consists of multiple layers of cells without the usual cellular organelles for energy production and other regenerative mechanisms for cellular biostability.40 Lens fiber cells dependent upon a small number of lens surface cells and surrounding cells for support. Over time these support mechanisms require increased nourishment and more antioxidants.50
Decrease efficiency in these supportive mechanisms is inevitable in aging, but it is possible to counteract these age-related processes by maintaining a healthy ocular environment with optimally maintained levels of antioxidant and cellular metabolism to ensure optimal lens function.64 Aging and oxidative stress, in particular, affects the entire body. Free radical proliferation can be minimized in the eye through proper diet and lifestyle, positively affecting overall health.
Maintaining a healthy ocular environment begins by avoiding common lifestyle and environmental risks that promote eye disease, cataract development in particular, and by following dietary and nutritional recommendations that support overall eye health.
Risk Factor Avoidance
Environmental risk factors to avoid include smoking, excessive alcohol consumption, excessive exposure to sunlight, especially UV radiation, and exposure to X-rays and gamma radiation.
Dietary Recommendations
Recommendations include increased consumption of vegetables and fruits, “good fats” found in oily fish (e.g., salmon and tuna), whole grains, and legumes, and minimal consumption of saturated fats and cholesterol.106 Consuming foods rich in the carotenoids lutein and zeaxanthin is especially important.
Nutritional Supplement Support
Important nutritional supplements for maintaining healthy eyes include coenzyme Q10 (CoQ10), potassium, magnesium, Ginkgo, bilberry, and taurine.
CoQ10. CoQ10 is an antioxidant that improves mitochondrial function in the retina. This function is linked to age-related macular degeneration.96,83
Potassium and magnesium. Decreased potassium and magnesium concentrations are found in a lens with cataract.
Gingko biloba and bilberry. Gingko biloba107 and bilberry support restoration of microcapillary circulation to the eye by protecting and strengthening ocular blood vessels.75 Gingko and bilberry can be effectively combined with daily doses of 400 mcg of selenium, 500 mg glutathione, and 300 mg of lipoic acid.33,75 Molecular and cellular assessment of gingko biloba extract as an ophthalmic drug determined it was an excellent antioxidant that readily scavenged free radicals, inhibited oxidative damage to proteins, and protected cells from light-mediated stress and DNA breakage, but did not alter endogenous antioxidant enzyme activity or protect against phototoxicity. It significantly retarded lens opacification in cataracts induced in rats.87
SUMMARY
This protocol provides information about cataracts; its nature, etiology, physiology, pathophysiology, and current treatments. Nutritional approaches to protecting the eye and preventing or slowing cataract progression of cataracts is provided. This information on cataracts and nutritional supplements should enable the reader to understand the beneficial effects of nutrition on cataract prevention.
Scientific Summary
The most widely accepted conventional surgical treatment is removal of the lens and implantation of an artificial lens (IOL). Surgical treatment is recommended when a cataract progresses to the point that it impairs visual function. Before this point is reached, conventional medicine often takes a “watchful waiting” approach, considering cataracts to be an age-related, unfortunate, but inevitable, fact of life. In contrast are a growing contingent of physicians, researchers, and nutritional scientists who have a more proactive view of cataract prevention and treatment. This holistic approach to maintain healthy lens function and eye health includes awareness of risk factors (e.g., smoking, alcohol, and sunlight), compliance with a sensible diet (e.g., low-fat, high-fiber), exercising, and nutritional therapy specifically for the eye.
Lifestyle Changes
Wear protective eyewear and avoid the following risk factors:
- Avoid smoking, excessive alcohol consumption, exposure to sunlight (particularly UV radiation), and excessive exposure to X-ray and gamma irradiation.
- Life Extension’s Solarshield sunglasses to protect from:
- blue and UV radiation
- preservation of essential macular pigments
LIFE EXTENSION’S INTEGRATED PROTOCOL
Supplement Recommendations
- Glutathione: 500 mg daily
- Vitamin C: 500 mg daily
- Vitamin B2: 50–150 mg daily
- Selenium: 200–400 mcg daily
- Vitamin E: 400 IU daily
- Gamma E Tocopherol w/Sesame Lignans: 1 softgel daily
- R-dihydro-lipoic acid: 150–300 mg daily
- N-acetyl-cysteine: 600 mg daily
- Melatonin: 300 mcg–3 mg at bedtime
- Vitamin B6: 50-250 mg daily
- Acetyl-L-carnitine arginate: three-four capsules daily
- Aminoguanidine: 150–300 mg daily
- Carnosine: 500–1000 mg daily
- Life Extension Mix: 3 tablets, 3 times daily, provide N-acetyl-cysteine, selenium, inositol, vitamins B2, B6, C, and E, bioflavonoids, and many other antioxidants and anti-glycating nutrients.
- Brite Eyes II: One-two drops in each eye daily
- Lutein Plus: One tablespoon daily taken with a fatty meal.
- Super Zeaxanthin with Lutein: One-two capsules daily.
- Coenzyme Q10: 100–200 mg daily
- Potassium: 400 mg daily, but consult your physician
- Magnesium: 800 mg daily
- Gingko biloba: 120 mg daily
- Bilberry: 100 mg daily
- Kyolic Reserve Garlic: One-three capsules daily
Note: Many of the nutrients suggested may be contained in the Life Extension Mix
For More Information
Contact the National Eye Health Education Program of the National Institutes of Health, (301) 496-5248, or the American Society of Cataract Surgery, (703) 591-2220.
Product Availability
Life Extension Mix, Brite Eyes II, glutathione, Super Carnosine, Super Absorbable CoQ10, Solarshield sunglasses, Super Zeaxanthin with Lutein, vitamin C, vitamin B2, vitamin B6, vitamin E, Gamma E Tocopherol with Sesame Lignans, gingko biloba extract, bilberry extract, R-dihydro-lipoic acid, potassium, magnesium, melatonin, Kyolic Reserve Garlic, N-acetyl-cysteine, acetyl-L-carnitine arginate, and selenium can be ordered by calling (800) 544-4440 or by ordering online at www.lef.org.
Robert Sachs, Ph.D. is a medical writer specializing in the therapeutic area of ophthalmology. He has prepared FDA submissions for new ophthalmologic devices and drugs and worked in cutting-edge technology companies developing a range of products in fields of standard and environmental medicine.
Sections were written and edited by Randall Lee Kohl, Ph.D., R.Ph., F.C.P., Senior Editor for LE Publications, Inc. Please direct only your comments to rkohl@lef.org. Direct your questions to the Life Extension Health Advisory staff at (800) 544-4440. |