A cataract is a cloudy or opaque area in the lens of the eye. When an doctor looks in the eye with an ophtalmoscope, he or she can see a dark area in the lens. The darker and larger the cataract, the more it interferes with vision. Once a cataract is formed, I am not aware of nutritional approaches that could reverse this process. Cataract eye surgery remains the best treatment. Therefore, it is best to take steps early in life to prevent or reduce the likelihood of cataract formation and thus reduce the likelihood of cataract operation and lens removal. Improvement in vision after cataract surgery has been shown to have a positive effect on mental abilities. After all, vision is an extension of the brain.

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Supplements helpful for cataract prevention
Please keep in mind that there are a number of eye disorders, and if you happen to have a serious problem with vision you should visit your doctor.
   Various antioxidants may be helpful in prevention or reducing the risk of cataract formation. Some may even help improve vision in certain cases. However, not enough research is available to determine which one of these supplements, in what dosage, or in what combinations are most helpful.

Lutein is potentially helpful in slowing the process of cataract formation. Lutein is a carotenoid found in green and leafy vegetables such as kale and spinach, and it is also available as a supplement.

Alpha lipoic acid is a powerful antioxidant and helpful for those with diabetes.

Vitamins C and Vitamin E could be helpful, but there is no reason to take high doses. 

Curcumin has powerful antioxidant abilities.

Selenium has been linked with a reduced risk of cataract. Selenium activates the antioxidant enzyme glutathione peroxidase, protecting cell membranes from oxidative damage. A dosage of 100 mcg a day seems to be sufficient.

Bilberry has been studied in rodents as a way to prevent cataracts.

Ginkgo biloba has excellent antioxidants.

Cacao - natural antioxidants from cacao are helpful. Good news for chocolate lovers, proanthocyanidins, compounds found in cacao, have been shown to reduce the risk of cataracts in rodents.    

Cataract Diet - Foods as cause of cataract formation
High intake of fruit and vegetables has a protective effect on cataract. High intake of sugar and high glycemic carbohydrates increases the risk for cataracts.
   People who eat lots of high glycemic index foods increase their risk of developing a cataract. Glycemic index, or GI, refers to how rapidly a food causes blood sugar to rise. High glycemic index foods, like white bread, pasta, and potatoes, tend to spur a quick surge in blood sugar, while low-GI foods, such as lentils, soybeans, and many high-fiber grains, create a more gradual increase in blood sugar.
   People who eat lots of yellow or dark leafy vegetables, as well as foods rich in vitamin E, reduce their risk of developing cataracts. Lutein and zeaxanthin are the only carotenoids detected in the human lens and these nutrients play a role in preserving lens clarity. Archives of Ophthalmology, January 2008.

Causes of cataracts
Congenital cataract is uncommon but is one of the causes at birth. Secondary cataracts form as we age. Oxidation and high blood sugar - mostly from eating too many simple carbohydrates - are two common causes. Excessive sun exposure is also a cataract cause. It is thought that the more sunlight a person is exposed to in life, the greater the risk for a cataract. Airline pilots are at higher risk of developing cataracts because of exposure to cosmic rays while aloft.
   An increase in exposure to ultraviolet radiation as result of ozone depletion in the stratosphere could in future lead to a considerable increase in the incidence of cataracts in the US population. Ozone screens out most of the ultraviolet radiation coming from the sun. Although progress is being made in reducing the degree of ozone depletion, Dr. Sheila K. West of Johns Hopkins Hospital, Baltimore and colleagues note in the American Journal of Epidemiology that cataracts are still a health effect of particular concern. They also note that unlike skin cancer, which is much more prevalent in those with light skin, cataracts affect African Americans at higher rate than Caucasians.

Cataract symptom
Some of the symptoms of a cataract include cloudy or blurry vision, problems with light, including headlights that seem too bright, glare from lamps or bright sunlight, or a halo around lights, difficulty reading, faded colors and poor night vision. These symptoms may depend on the location of the cataract in the eye.

Cataract Surgery
If the cataract is advanced, then cataract eye surgery remains the best option. Surgery for cataracts can help older drivers see the road more clearly, and may get some former drivers behind the wheel again. A cataract is a clouding of the eye's lens that commonly arises as people age. When symptoms, such as blurred vision and trouble seeing at night, begin to interfere with daily life, surgery may be necessary. The procedure involves removing the clouded lens and replacing it with an artificial one.

Smokeless Tobacco and Cataract
Using snuff or chewing tobacco is associated with an increased likelihood of developing cataracts. Smokeless tobacco users have higher levels of cadmium in their blood than non-users. Cadmium present in tobacco inactivates superoxide dismutase, an antioxidant, resulting in oxidant damage to the lens of the eye.

Cataract Research Update
Long-term nutrient intake and 5-year change in nuclear lens opacities.
Arch Ophthalmol. 2005 Apr;123(4):517-26.
Jacques PF, Taylor A, Moeller S, Hankinson SE, Rogers G, Tung W, Ludovico J, Willett WC, Chylack LT Jr.
Jean Mayer USDA Human Nutrition Research Center on Aging, School of Nutrition Science and Policy, Tufts University, Boston, Mass
To determine if usual nutrient intake is related to a 5-year change in the amount of lens nuclear opacification assessed by computer-assisted image analysis. DESIGN: A sample of 408 Boston, Mass-area women from the Nurses' Health Study aged 52 to 74 years at baseline participated in a 5-year study related to nutrition and vision. Usual nutrient intake was calculated as the average intake from 5 food frequency questionnaires that were collected over a 13- to 15-year period before the baseline evaluation of lens nuclear density. Duration of vitamin supplement use before baseline was determined from 7 questionnaires collected during this same period. We assessed the degree of nuclear density (opacification) using computer-assisted image analysis of digital lens images with amount of nuclear density measured as a function of average pixel gray scale, ranging from 0 (clear) to 255 (black). Median (range) baseline and follow-up nuclear densities were 44 (19 to 102) and 63 (32 to 213). The median (range) 5-year change in nuclear density was 18 (-29 to 134) and was positively correlated with the amount of opacification at baseline . Geometric mean 5-year change in nuclear density was inversely associated with the intake of riboflavin (P trend = .03) and thiamin and duration of vitamin E supplement use. Our results suggest that long-term use of vitamin E supplements and higher riboflavin and/or thiamin intake may reduce the progression of age-related lens opacification.

Dietary fat intake and early age-related lens opacities.
Am J Clin Nutr. 2005 Apr;81(4):773-9. Lu M, Taylor A, Chylack LT Jr, Rogers G, Hankinson SE, Willett WC, Jacques PF.
Nutritional Epidemiology Program and the Center for Ophthalmic Research, Department of Ophthalmology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA.
Dietary fat may affect lens cell membrane composition and function, which are related to age-related cataract. The objective of the study was to examine the association between long-term dietary fat intake and the prevalence of age-related nuclear, cortical, and posterior subcapsular lens opacities. DESIGN: Women (n = 440) aged 53-73 y from the Boston area without previously diagnosed cancer, diabetes, or cataract were selected from the Nurses' Health Study cohort. Intakes of total fat and selected fatty acids were calculated as the average of intake data from 5 food-frequency questionnaires collected between 1980 and the study eye examination (1993-1995). Nuclear opacity was defined as grade >/=2.5, cortical opacity as grade >/=1.0, and posterior subcapsular opacity as grade >/=0.5 according to the Lens Opacities Classification System III. RESULTS: There were significant positive associations between linoleic and linolenic acid intakes and the prevalence of nuclear opacity. The odds ratios for nuclear opacity in women with intakes in the highest quartile and women with intakes in the lowest quartile were 2.2 for linoleic acid and 2.2 for linolenic acid. There were no significant associations between intakes of any type of fat and either cortical or posterior subscapular opacity. CONCLUSIONS: High intake of the 18-carbon polyunsaturated fatty acids linoleic acid and linolenic acid may increase the risk of age-related nuclear opacity. Further study is needed to clarify the relation between dietary fat and cataract risk.

Effects of DL-alpha-lipoic acid on the experimentally induced diabetic cataract in rats
Zhonghua Yan Ke Za Zhi. 2004 Mar;40(3):193-6.
To investigate whether DL-alpha-lipoic acid can offer cataract protection in diabetic rats. METHOD: 36 Brown-Norway (BN) specific pathogen free (SPF) rats (7 week-old, female), were divided into 3 groups comprising of the diabetes mellitus (DM) group (14 rats), the diabetes mellitus treated with lipoic acid (DM + LA) group (14 rats), and the control (CTL) group (8 rats). The diabetic cataract was induced by streptozotocin (STZ) injection. CONCLUSION: Alpha lipoic acid ingested orally can effectively reduce STZ-induced blood glucose and inhibit diabetic cataract formation in rats.

Age-related cataract in a randomized trial of beta-carotene in women.
Ophthalmic Epidemiol. 2004 Dec;11(5):401-12.
To examine the development of age-related cataract in a trial of beta-carotene supplementation in women. The Women's Health Study is a randomized, double-masked, placebo-controlled trial originally designed to test the balance of benefits and risks of beta-carotene (50 mg on alternate days), vitamin E, and aspirin in the primary prevention of cancer and cardiovascular disease among 39,876 female health professionals aged 45 years or older. The beta-carotene component of the trial was terminated early after a median treatment duration of 2.1 years. Main outcome measures were visually-significant cataract and cataract extraction, based on self-report confirmed by medical record review. RESULTS: There were 129 cataracts in the beta-carotene group and 133 in the placebo group. For cataract extraction, there were 94 cases in the beta-carotene group and 89 cases in the placebo group. Subgroup analyses suggested a possible beneficial effect of beta-carotene in smokers. CONCLUSIONS: These randomized trial data from a large population of apparently healthy female health professionals indicate that two years of beta-carotene treatment has no large beneficial or harmful effect on the development of cataract during the treatment period.

Lutein, but not alpha-tocopherol, supplementation improves visual function in patients with age-related cataracts: a 2-y double-blind, placebo-controlled pilot study.
Nutrition. 2003 Jan;19(1):21-4.
We investigated the effect of long-term antioxidant supplementation (lutein and alpha-tocopherol) on serum levels and visual performance in patients with cataracts. Seventeen patients clinically diagnosed with age-related cataracts were randomized in a double-blind study involving dietary supplementation with lutein (15 mg; n = 5), alpha-tocopherol (100 mg; n = 6), or placebo (n = 6), three times a week for up to 2 y. Serum carotenoid and tocopherol concentrations were determined with quality-controlled high-performance liquid chromatography, and visual performance (visual acuity and glare sensitivity) and biochemical and hematologic indexes were monitored every 3 mo throughout the study. Changes in these parameters were assessed by General Linear Model (GLM) repeated measures analysis. RESULTS: Serum concentrations of lutein and alpha-tocopherol increased with supplementation, although statistical significance was reached only in the lutein group. Visual performance (visual acuity and glare sensitivity) improved in the lutein group, whereas there was a trend toward the maintenance of and decrease in visual acuity with alpha-tocopherol and placebo supplementation, respectively. No significant side effects or changes in biochemical or hematologic profiles were observed in any of the subjects during the study. CONCLUSIONS: Visual function in patients with age-related cataracts who received the lutein supplements improved, suggesting that a higher intake of lutein, through lutein-rich fruit and vegetables or supplements, may have beneficial effects on the visual performance of people with age-related cataracts.

Human eye cells treated with lutein and zeaxanthin showed less damage after being exposed to ultraviolet rays, the sunlight ingredient considered a major contributor to cataracts. Cataracts occur when proteins in the eye's lens begin to clump together, forming a milky cloud that obscures vision. It is thought that the more sunlight a person is exposed to in life, the greater the risk for cataracts. Foods that contain particularly high doses of lutein and zeaxanthin include kale and spinach. Researchers at Ohio State University in Columbus grew human lens cells in a laboratory, then added lutein, zeaxanthin, vitamin E, or left the cells alone. The researchers then exposed the eye cells to ultraviolet (UV) radiation, in order to mimic the effect of sunlight. Lens cells mixed with lutein and zeaxanthin showed significantly less damage following UV-exposure than cells that had no shielding from antioxidants. Although vitamin E appeared to offer some protection from UV rays, it was surpassed by both lutein and zeaxanthin. SOURCE: Journal of Nutrition, December 2004.

Moderate exercise combined with dietary vitamins C and E counteracts oxidative stress in the kidney and lens of streptozotocin-induced diabetic-rat.
Int J Vitam Nutr Res. 2005 Jan;75(1):71-80.
Oxidative stress has a key role in the pathogenesis of diabetes-induced cataract formation and diabetic nephropathy. Daily moderate exercise and vitamins C and E (VCE) supplementation can be beneficial to diabetes due to reducing blood glucose and free radical production. The aim of this study was to analyze the effect of moderate exercise with vitamin VCE on lipid peroxidation (LP) and antioxidative systems in the kidneys and lens of streptozotocin-induced diabetic rats. Forty female In conclusion, these data demonstrate that lipid peroxidation increases in the lens and kidney of diabetic animals and this could be due to decreases in antioxidant vitamins and enzymes. However, dietary VCE with moderate exercise may strengthen the antioxidant defense system through the reduction of ROS and blood glucose levels. The VCE supplementations with exercise may play a role in preventing the development of diabetic nephropathy and cataract formation in diabetic animals.

Effects of oral Ginkgo biloba supplementation on cataract formation and oxidative stress occurring in lenses of rats exposed to total cranium radiotherapy.
Japan J Ophthalmology. 2004 Sep-Oct;48(5):499-502.
To determine the antioxidant role of Ginkgo biloba in preventing radiation-induced cataracts in the lens after total-cranium irradiation of rats with a single radiation dose of 5 Gy. METHODS: Sprague-Dawley rats were randomly divided into three groups. Group 1 received neither ginkgo biloba nor irradiation (control group). Group 2 was exposed to total-cranium irradiation, and group 3 received total cranium irradiation from a cobalt-60 teletherapy unit, plus 40 mg/kg per day of ginkgo biloba. At the end of the tenth day, the rats were killed and their eyes were enucleated to measure the antioxidant enzymes, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the lipid peroxidation level [malondialdehyde (MDA)]. RESULTS: Irradiation significantly increased both the MDA level and the activity of GSH-Px, and significantly decreased the activity of SOD in the rat lenses. Ginkgo biloba supplementation significantly increased the activities of SOD and GSH-Px enzymes and significantly decreased the MDA level. Total cranium irradiation of 5 Gy in a single dose promoted cataract formation, and ginkgo biloba supplementation protected the lenses from radiation-induced cataracts. CONCLUSIONS: We suggest that Ginkgo biloba is an antioxidant that protects the rat lens from radiation-induced cataracts.

Antioxidant micronutrients and cataract: a review of epidemiological evidence.
Gac Sanit. 2002 Dec;16 Suppl 2:29-40.
Cataract is one of the leading causes of blindness among the elderly and an important public health problem worldwide. Population ageing will lead to increased resources required to treat cataract. Epidemiological studies have suggested that intake of foods containing micronutrients with antioxidant potential may be protective against cataract, but the role of the individual antioxidant micronutrients on the cataract process has not been yet elucidated. Although surgical treatment to remove cataract is very effective, the incidence in developing countries is so high that it will overwhelm the capacity of surgical programs. An increased understanding of the aetiology of cataract may lead to the development of non-surgical strategies to delay o prevent cataract. A preventive approach appears to be essential to the global problems of cataract.

Antioxidant effect of curcumin in selenium induced cataract of Wistar rats.
Indian J Exp Biol. 2004 Jun;42(6):601-3.
Wistar rat pups treated with curcumin, a natural constituent of Curcuma longa before being administered with selenium showed no opacities in the lens. The lipid peroxidation, xanthine oxidase enzyme levels in the lenses of curcumin and selenium co-treated animals were significantly less when compared to selenium treated animals. The superoxidase dismutase and catalase enzyme activities of curcumin and selenium co-treated animal lenses showed an enhancement. Curcumin co-treatment seems to prevent oxidative damage and found to delay the development of cataract.

Ingestion of proanthocyanidins derived from cacao inhibits diabetes-induced cataract formation in rats.
Exp Biol Med (Maywood). 2004 Jan;229(1):33-9.
Proanthocyanidins derived from cacao have various antipathophysiological functions. We have tested whether dietary supplementation with proanthcyanidins prevents cataract formation in rats with diabetes induced by streptozotocin (STZ), using histological, histochemical, and biochemical analyses. Our findings suggest that proanthocyanidins from cacao inhibit diabetes-induced cataract formation possibly by virtue of their antioxidative activity.

Antioxidant and anti-cataract effects of Chlorella on rats with streptozotocin-induced diabetes.
J Nutr Sci Vitaminol (Tokyo). 2003 Oct;49(5):334-9.
The antioxidant activities of Chlorella in vitro and in vivo were investigated. Chlorella showed a strong antioxidant effect compared to various vegetables. To evaluate the antioxidant and anti-cataract effects in vivo, a 7.3% Chlorella powder was fed to rats with streptozotocin-induced diabetes for 11 wk. At the end of the experiment, Chlorella had decreased the blood glycated hemoglobin (hemoglobin A1c) and serum cholesterol levels significantly, however, it had not affected the serum glucose concentration. The serum lipid peroxide value (TBARS value) in the rats fed Chlorella was lower than that of the control rats. In the liver and kidney, Chlorella also reduced chemiluminescent intensities. In addition, it delayed the development of lens opacities. The lens lipid peroxide content of the rats fed Chlorella was lower than that of the control rats, however the differences were not significant. These results indicate that Chlorella has antioxidant activity and may be beneficial for the prevention of diabetic complications such as cataracts.

Oxidative damage to lens in culture: reversibility by pyruvate and ethyl pyruvate.
Ophthalmologica. 2006;220(1):52-7. Varma SD, Hegde KR, Kovtun S. Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD
It is generally believed that prophylactic intake of antioxidants is beneficial in delaying the onset of some aging manifestations such as cataract. However, whether such a supplementation will also be effective if the pathophysiological process has already set in remains a largely open question. We examined this possibility with lens changes leading to cataract formation, since cataract genesis is intimately related to a continued generation of reactive oxygen species (ROS) in the aqueous humor. Since the formation of cataract is a well-defined progressive disease, starting with an early refractive change and leading to gradual enhancement of opacification, we hypothesized that even a belated start with an appropriate anti-oxidant could halt the pathological process and delay cataract maturation and vision impairment. Using lens cultures, we tested this hypothesis with pyruvate, known to be an effective and highly potent ROS scavenger. Adding pyruvate to the culture medium after lenses had sustained a 50% damage was significantly effective in preventing progress. This was apparent by better maintenance of the active rubidium transport activity in these lenses compared to controls without pyruvate treatment. Glutathione levels were also higher in the pyruvate group.

Cataract in dog
A canine cataract can occur. At this point it appears that the causes of canine cataracts would be similar to that of humans and nutritional approaches as discussed above could be tried.

Cataract emails
Q. Have you heard about glutathione eye drops as a treatment for cataracts? I am a huge believer in taking glutathione in powder form orally which has helped my allergies tremendously. I just had one cataract removed surgically and have the other eye with just the beginnings of a cataract. I was hoping to possibly use glutathione eye drops to prevent it from getting worse.
   A. We are not familiar with glutathione eye drops and don't have experience using this product.

Q. Does Eyesight RX have any effect on cataracts?
   A. We have not done any studies regarding the use of Eyesight Rx for cataract treatment or prevention. Eyesight Rx was formulated to improve vision in those with age related visual decline.