Cataract Prevention
Filed Under Dr. Zoltan Rona (MD) |
Cataracts are the result of a process of clouding or opacification caused by free radical (molecular) damage to the sulphur-containing proteins in the lens of the eye. They are the leading cause of impaired vision and blindness in North America affecting approximately 4 million people. Over 40,000 cases of blindness are directly attributed to cataracts and cataract surgery is the most frequent major surgery performed on Medicare patients. Cataracts may have some relationship to a variety of eye diseases, diabetes, ultraviolet light or radiation exposure, injury or surgery, viral infections, toxic heavy metal excess in the body (especially cadmium, bromine, cobalt, iridium and nickel), heredity, galactosemia (milk sugar toxemia) and advancing age.
The lens protects itself from free radical damage with antioxidants (free radical scavengers) like superoxide dismutase (SOD), catalase, glutathione, methionine, vitamin A, beta carotene, vitamin B2 (riboflavin), E, C, bioflavonoids, zinc and selenium. Studies show that cataract formation may be retarded by increasing the intake of antioxidants. To prevent cataracts, avoid sugar, white flour products, milk, high fat foods and processed foods, all of which create free radicals. Eat more legumes, garlic and onions - high sources of sulphur-containing amino acids, yellow vegetables (for carotenes) and fresh fruits and raw vegetables for their vitamin C content. Other cataract preventive foods are spinach, cloves, water chestnuts, yams, lycium, black beans, and endive. Fresh juices that are recommended are combinations of carrot, spinach, beet, cucumber, endive and parsley. Cataract sufferers should avoid direct sunlight, bright lights of other types and wear protective sunglasses when outdoors.
Vitamin C is a very important antioxidant for the eye, concentrated in amounts 30 - 50 times greater in the aqueous humor of the eye than in the blood. Studies show that vitamin C levels are greatly reduced or absent in the lens with a cataract and that supplementation (1000 mgs. or more daily) can halt cataract progression. If you are already taking vitamin C, the advice is to take more, provided the higher dosages are well tolerated by the intestines. Bioflavonoids, especially bilberry extract, pycnogenol (from pine bark or grape seed extract) and quercetin also provide strong antioxidant protection.
Glycine, glutamic acid and cysteine are the three amino acids that make up the antioxidant, glutathione (also referred to as GSH) found in very high concentrations in a healthy lens. GSH levels are found to be low in all cases of cataracts and can be increased by supplementing the amino acid precursors, glycine, glutamic acid and cysteine. Supplementation of whey protein (e.g. Immunocal®) is a proven way of increasing GSH blood levels. An ancient Chinese herbal formula called “Hachimijiogan” also helps raise the levels of GSH.
The amino acid, L-carnosine prevents the formation of advanced glycated end products (protein crosslinks) in the lens and can therefore prevent cataracts. Dosages required are 1000 mg, 3 times daily. N-acetyl-L-carnosine eye drops show some promise in being able to dissolve existing cataracts but more evidence is needed before this becomes a reliable alternative to surgery.
Other nutrients of importance for cataract prevention are zinc, copper and manganese which are all co-factors in the production of SOD (superoxide dismutase), a powerful antioxidant. The amino acid, lysine, important in collagen formation, may be helpful in lens repair as well. A natural health care practitioner can help with prescribing a personalized regime of vitamin, mineral and herb supplements designed for both cataract prevention and optimum eye health.
Dr. Rona
