Cataract Nutrition, Macular Degeneration, Glaucoma, Diabetes Research

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NUTRITIONAL EYE RESEARCH SUMMARIES

- Preventing Blindness Through Nutritional Intervention -

 

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QUICK INDEX

(Just Click On Eye Condition)

a.. MACULAR DEGENERATION STUDIES

b.. GLAUCOMA STUDIES

c.. DIABETIC EYE STUDIES

d.. CATARACT STUDIES

e.. RETINITIS PIGMENTOSA STUDIES

f.. DISCUSSION & COMMENTS

Underlined references are linked directly to PUBMED abstracts for those

with inquiring minds.

A few abstracts were not found online.

 

 

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MACULAR DEGENERATION STUDIES

 

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1. Risk of developing advanced disease was reduced by about 25% in those

with intermediate damage from taking 500 mg of vitamin C, 15 mg of beta

carotene, 400 IU of vitamin E and 80 mg of zinc on a daily basis. Ferris, et

al. Archives of Opthalmology; Oct 01. (Ed. Note: This study is not yet

available online. We believe a more absorbable form of zinc, such as Opti-zinc,

would provide better results with a lower dose, as well as substituting lutein

for beta carotene. High doses of zinc can cause anemia.)

 

2. A preliminary study showed those consuming lutein from either spinach

or supplements demonstrated improvement of some of the early vision loss from

" dry " macular degeneration. Richer, J. Amer Optom Assoc; Jan 1999.

 

3. Consuming 6 mg of the caroteinoid lutein (w/ it's co-nutrient

zeaxanthin) daily (Ed. Note: equiv. to 4-8 ounces of spinach daily, depending on

reference) for five months was shown to significantly increase macular pigment

density, which protects from harmful blue wavelength light believed to be most

responsible for macular degeneration. Landrum, et al. Exp Eye Res 1997

Jul;65(1):57-62

 

4. High macular pigment density was associated with the retention of

youthful visual sensitivity, which suggested that increasing macular pigment may

retard age-related declines in visual function. Hammond, et al. Invest

Ophthalmol Vis Sci 1997 Aug;38(9):1795-801.

 

5. Persons who had the lowest serum levels of lycopene, the most abundant

carotenoid in the serum, were twice as likely to have macular degeneration when

compared to those with the highest levels. Mares-Perlman, et al. Arch Ophthalmol

1995 Dec;113(12):1518-23

(Ed. Note: Consumption of high levels of lutein and lycopene (a carotenoid

found in tomatoes) has also been associated with dramatically lower cancer rates

for lung and prostate cancer!)

 

6. Those consuming lutein rich foods (spinach and collard greens) five

days per week were 8 times less likely to develop macular degeneration as those

consuming them once per month Seddon, et al. JAMA 1994 Nov 9;272(18):1413-20

(Ed. Note: Consumption of large amounts of spinach may be associated with

kidney stones due to its high levels of oxalic acid, and also is contradindicted

in those taking blood thinners due to its vitamin K. Standardized lutein

supplements may be preferred. It is estimated the cost of consuming lutein-rich

foods to get 10 mg/day is around $1.00/day)

 

7. The ARMD population manifested decreased intake of vitamin E,

magnesium, zinc, vitamin B6 and folic acid. Patients with advanced ARMD taking

antioxidants twice daily maintained vision in their better functioning eyes

significantly better than those taking a placebo. Richer, J Am Optom Assoc 1996

Jan;67(1):12-29 J Am Optom Assoc 1996 Jan;67(1):30-49

 

8. Smokers with early macular degeneration who consumed the lowest

amounts of carotenoids were nearly 6X as likely to develop advanced macular

degeneration than those consuming the highest amounts. Seddon, et al. J. Amer

Med Assoc; 1994.

 

9. In a clinical trial 60% of subjects with ARMD or diabetic macular

edema who received 500 mg of vitamin C, 400 IU of vitamin E, 15,000 IU of beta

carotene and selenium showed either improvement or no further progression of

their disease. So Med J, 1987.

Ed Note: More recent evidence indicates that other carotenoids are more

important than beta carotene, and too much beta carotene in the absence of

lutein/zeaxanthin may be more harmful than good.

 

10. The evidence suggests that carotenoids and antioxidant vitamins may

help to retard some of the destructive processes in the retina and the retinal

pigment epithelium which are responsible for age-related degeneration of the

macula. Am J Clin Nutr 1995 Dec;62(6 Suppl):1448S-1461S

 

11. The minerals copper and zinc are required to synthesize superoxide

dismutase and other enzymes in the retina which scavenge free radicals,

preventing the oxidative damage which plays a role in the development of drusen,

an early sign of Age-Related Macular Degeneration. Olin, et al: Proc Soc Exp

Biol Med 1995 Apr;208(4):370-7

 

12. Glutathione and its related enzyme precursor amino acids

(N-Acetyl-Cysteine, L-glycine, and glutamine and selenium) are protective

against damage to human retinal pigment epithelium cells. Sternberg, Davidson,

Jones, et al. Invest Ophthalmol Vis Sci 1993 Dec;34(13):3661-8

 

13. Quercetin protected bovine retinas in vitro from induced lipid

peroxidation, especially when combined with vitamin E, suggesting a potential

protective effect in age-related macular degeneration. Ophthalmic Res

1996;28(3):184-92.

 

14. Deficiency of taurine, an amino acid, has been shown to lead to

retinal degeneration and supplementing it has been used with some success to

prevent, treat and stabilize retinal changes. Altern Med Rev 1998

Apr;3(2):128-36. Oftalmol Zh 1989;(8):463-5 Brain Res Brain Res Rev 1991

May-Aug;16(2):151-69 J Neurosci Res 1987;18(4):602-14

 

15. After 18 months, subjects with macular degeneration who took

antioxidants on a consistent basis were 2.5X more likely to improve on visual

acuity testing, and four times less likely to deteriorate in their worst eye,

compared to those who took them less consistently. Olson, et al. J. Cat Refr

Surg, Mar 1991.

 

16. Patients with confluent soft drusen, or " pre-wet " ARMD, were found to

have evidence of vitamin B6 deficiency. B. Lane, Ann Mtg Amer Coll of Nutrition,

1991.

 

17. General measures for prevention and remediation of macular

degeneration would include a combination of supplementation with trace elements,

antioxidants and other vitamins, ...increasing physical fitness, improving

nutrition (e.g. avoiding hydrogenated oils), abstaining from smoking, and

protection from excessive light exposure. Eur J Med Res 1997 Oct 30;2(10):445-54

 

18. There is an association between both low serum selenium levels and

current smoking status and the development of age-related macular degeneration.

Doc Ophthalmol 1992;81(4):387-400 Mayer, et al. Acta Ophthalmol Scand 1998

Feb;76(1):62-7

 

19. There was an inverse relationship between dietary pro-vitamin A

carotenoid and vitamin E consumption and the incidence of large macular drusen,

as well as between zinc levels and the incidence of retinal pigment

abnormalities. Am J Epidemiol 1998 Jul 15;148(2):204-14

 

20. The evidence suggests that carotenoids and antioxidant vitamins may

help to retard some of the destructive processes in the retina and the retinal

pigment epithelium that lead to age-related degeneration of the macula.

Snodderly, Am J Clin Nutr 1995;62(6 suppl):1448S-61S

 

21. Subnormal zinc and/or vitamin E serum levels may be associated with

as much as an 82% increased risk of advanced age-related macular degeneration.

Vitamin C and lipoic acid help to recycle vitamin E in the retinal tissues.

Ishihara, et al. Nippon Ganka Gakkai Zasshi 1997 Mar;101(3):248-51. Delcourt

C. et al. Arch Ophthalmol 1999 Oct;117(10):1384-90 Stoyanovsky DA, et al. Curr

Eye Res 1995 Mar;14(3):181-9

 

22. In a study of adults over 60 there was found to be a significant link

between risk of macular degeneration and low blood levels of vitamin E as well

as increased sun exposure. Belda, et al Mech Ageing Dev 1999 Mar 1;107(2):159-64

 

23. A statistically significant improvement in visual acuity was observed

after treatment with Ginkgo biloba extract in a double blind, placebo controlled

study of macular degeneration patients. Lebuisson DA, et al. Presse Med 1986

Sep 25;15(31):1556-8

 

24. Those consuming fish more than once per week were only half as likely

to develop macular degeneration than those consuming it less than once per

month. Those consuming the highest amount of cholesterol in their diet were 2.7

times more likely to develop advanced macular degeneration. Smith, et al. Arch

Ophthalmol 2000 Mar;118(3):401-4

 

25. Dietary enzymes increase glutathione synthesis which can prevent free

radical-induced apoptosis (cell suicide) and may help prevent or treat AMD.

Progress in Retinal and Eye Research, 2000, Vol. 19, Iss.2 pp 205-221 (No

abstract available)

 

 

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GLAUCOMA STUDIES

 

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1. In a study of open angle glaucoma patients who received 150mg of Alpha

Lipoic Acid each day, 45-47% of the eyes had enhancement of color visual fields

and visual sensitivity when compared to controls using only topical medical

therapy. More advanced cases had an even better response compared to their

controls. Filina, et al., Vestn Oftalmol 1995 Oct-Dec;111(4):6-8

 

2. Pretreatment with alpha lipoic acid has been found to reduce neuronal

damage from excitotoxic damage from cyanide, glutamate and iron ions,

demonstrating a strong neuroprotective effect for this substance in nerve

tissue. It may be useful in treating glaucoma. (Ed. Note: Recent evidence

points to the importance of neuroprotection against glutamate in glaucoma

patients, with many medications now heavily promoting this property!) J Cereb

Blood Flow Metab 1995 Jul;15(4):624-30 Altern Med Rev 1998 Aug;3(4):308-11

(Other ALA/Neuroprotective Studies)

 

3. The eyes of open angle glaucoma patients were found to have

significantly lower vitamin C levels, as well as higher levels of lipic

peroxidation byproducts compared to normals. Aleksidze, et al. Oftalmol Zh

1989;(2):114-6

 

4. Patients suffering from open angle glaucoma and normal-tension

glaucoma who were given magnesium twice daily showed improvement of the visual

field and reduced peripheral vasospasms (which can cause glaucoma, stroke and

heart attack) after four weeks of treatment. Gaspar, et al; Ophthalmologica

1995;209(1):11-3

 

5. Glaucoma patients treated with vitamin B12 for over 5 years

demonstrated better visual acuity and better overall control of their disease.

Glacome, 1992; Nippon Ganka Kiyo. 1965 Mar.; Oftalmol Zh. 1965; 20(6); Klin

Oczna 1974 Nov;44(11):1183-7

 

6. Besides beta carotene, other carotenoids found in dark green leafy

vegetables appear to be much more essential to the health of the eye. Several

studies have shown that lutein and zeaxanthin supplements may slow vision loss

in glaucoma, and in some cases improve eyesight. Science News, Volume 146.

 

7. Anthocyanosides, compounds found in the herb bilberry, were shown to

markedly improve vascular resistance of the capillary wall in the ciliary body

of the eye (the source of excess fluid production). Boll. Ocul. 65 789-95, 1986

 

8. Chronic open angle glaucoma patients had a statistically significant

lower thiamine blood level than controls along with poor absorption of that

nutrient. Asregadoo, Ann Ophthalmol 1979 Jul;11(7):1095-1100

 

9. Lipoic acid may be useful in the treatment of glaucoma and may help

prevent ischemic optic nerve damage. Altern Med Rev 1998 Aug;3(4):308-11

 

10. The scientific literature supports recommending lipoic acid in

complex with vitamins B1, B2, B5, B6 (pyridoxal phosphate), and vitamin C to

glaucoma patients. Filina, AA & Sporova, NA. Vestn Oftalmol 1991

May-Jun;107(3):19-21

 

11. Vascular obstruction and hindrance of the blood flow and impaired

nutrition of neuronal tissue might be the primary causes of glaucoma. Sonnsjo

& Krakau, Acta Ophthalmol (Copenh) 1993 Aug;71(4):433-44

 

12. Ginkgo biloba is a potentially important agent in the treatment of

glaucoma. It improves central and peripheral blood flow, reduces vasospasm,

reduces serum viscosity, has antioxidant activity, platelet activating factor

inhibitory activity, and inhibits apoptosis and excitotoxicity - all factors in

preventing glaucoma vision loss. (Ed. Note: magnesium also has been shown to

decrease peripheral vasospasms, improving blood flow and is neuroprotective, as

well.) Ritch R. Med Hypotheses 2000 Feb;54(2):221-35

 

13. The fatty acid DHA (abundant in fish oil), along with B Complex and

vitamin E were shown to be helpful in preventing or delaying vision loss

associated with glaucoma. Cellini M, et al., Acta Ophthalmol Scand Suppl

1998;(227):41

 

14. Ginkgo biloba extract (40mg, three times daily), increased diastolic

blood flow by 23% in the ophthalmic artery in glaucoma patients and may be

helpful in protecting the optic nerve from further damage and subsequent visual

field loss. Chung HS, et al. J Ocul Pharmacol Ther 1999 Jun;15(3):233-40 (Ed.

Note: Ginkgo must be used with caution by those taking Coumadin, as it may

increase its effect - possibly eliminating the need for it??)

 

15. Besides alpha lipoic acid, other nutrients which are neuroprotective

include vitamin E, ginkgo biloba, pycnogenol (from grape seed extract or pine

bark), and flavonoids. Kobayashi MS, et al. Free Radic Res 2000 Feb;32(2):115-24

 

 

 

 

 

 

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DIABETIC EYE STUDIES

 

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1. Alpha Lipoic Acid can significantly reduce diabetic cataract

formation, as well as neuropathy, and would seem to be an ideal neuroprotective

substance in the treatment of all oxidative brain and neural disorders involving

free radical processes. Packer, L., Ann N Y Acad Sci 1994 Nov 17;738:257-64

Packer, L. Free Radic Biol Med 1997;22(1-2):359-78

 

2. Vitamin E significantly improved glucose tolerance in non-insulin

dependent diabetics, which should very likely result in fewer diabetic

complications. Paolisso, G, et al. Am J Clin Nutr 1993; 57:650-56.

 

3. Diabetic patients with high serum magnesium levels were less likely to

develop severe diabetic retinopathy compared to those with low levels. Diabetes

1978 Nov;27(11):1075-7.

 

4. Chromium, high-dose vitamin E, magnesium, soluble fiber, and possibly

taurine appear likely to lessen risk for macrovascular disease (retinopathy) in

diabetics. McCarty, Med Hypotheses 1997 Aug;49(2):143-52.

 

5. Bioflavonoids, including those from bilberry extract, were found to

normalize blood vessel permeability in diabetic patients, significantly reducing

the risk of diabetic retinopathy. Long term use of multiple antioxidants

inhibits the development of early stage diabetic retinopathy. Valenci, et al.

Diabet Med 1996 Oct;13(10):882-8. Detre, et al. Clin Physiol Biochem

1986;4(2):143-9 Kowluru RA, et al. Diabetes 2001 Aug;50(8):1938-42

 

6. Seven of fifteen patients with Type I diabetic retinopathy who were

given vitamin B12 along with their daily insulin injections were found to have

complete regression of retinal signs after 12 months. Kornerup T, Strom L. Acta

Paediatr 1958.

 

7. 79% of 37 patients with visible diabetic retinal abnormalities

improved after taking 160 mg of bilberry extract twice daily, compared to 0% of

the placebo control group, and 86% of those with abnormalities of angiography

findings showed moderate to considerable improvement. (These improvements were

noted within one month.) Perossini, et al. Ann Ottalmol Clin Ocul 1987.

 

8. 73% of type I and II diabetics who took chromium supplements reduced

their requirement for insulin or oral hypoglycemic agents. Taking chromium and

niacin together reduced fasting blood sugar levels and improved glucose

tolerance. J Trace Elem Exp Med 1995: 8:183-90; Urberg M, Zemel MB, Metabolism

1987; 36:896-99.

 

9. Low magnesium levels might increase the risk of ischemic heart disease

and severe retinopathy in diabetics, while chromium increases insulin

sensitivity and raises the 'good' HDL cholesterol. Tuvemo, T. Pediatrician

1983-85;12(4):213-9

 

10. Low serum carotenoid levels were found to be directly related to an

increased risk for developing insulin resistance and diabetes. Ford, et al. Am J

Epidemiol 1999 Jan 15;149(2):168-76

 

11. Both Panax and American ginseng was shown to normalize glucose

tolerance tests, and reduced blood sugar spikes in Type II diabetics after

consumption of a sugar solution. Vuksan V, et al., Arch Intern Med 2000 Apr

10;160(7):1009-13

 

12. In one study all 38 patients with insulin-dependent diabetes were

required to lower their insulin dose to avoid hypoglycemia after taking 200mg

of Gymnema Sylvestre extract twice daily. Shanmugasundaram ER, et al. J

Ethnopharmacol 1990 Oct;30(3):281-94

 

 

 

 

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CATARACT STUDIES

 

 

 

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1. Subjects taking vitamin C supplements for more than 10 years had a

45-77% lower risk of early lens opacities (cataracts) and 83% lower risk of

moderate lens opacities. The higher the serum levels, the lower the risk of

cataracts. Jacques, et al. The American Journal of Clinical Nutrition, Oct.

1997. S.E. Hankinson, et al. 1992. BMJ: 305: 335-339. Simon JA, Hudes ES J Clin

Epidemiol 1999 Dec;52(12):1207-11

 

2. Vitamin E, vitamin C, alpha-lipoic acid, and taurine appear to offer

protection against lens damage caused by low level radiation. Bantseev, et al.

Biochem Mol Biol Int 1997 Sep;42(6):1189-97.

 

3. Dietary lutein and cryptoxanthin were associated with 70% lower risk of

nuclear cataracts in those under age 65. Lyle, et al. Am J Clin Nutr 1999

Feb;69(2):272-7.

 

4. Dietary intake of protein, vitamins A, C, E, and carotene, niacin,

riboflavin, and thiamine significantly decreased the risk of all cataract types.

(Combining a variety of antioxidant nutrients produced the greatest effect.)

Cumming RG, et al. Ophthalmology 2000 Mar;107(3):450-6 Leske, et al. Arch

Ophthalmol 1991 Feb;109(2):244-51.

 

5. Vitamin E taken with bilberry extract stopped the progression of senile

cortical cataracts in 97% of the eyes of human subjects. Ann Ottalmol Clin Ocul,

1989.

 

6. Low blood levels of vitamin E were associated with approximately twice

the risk of both cortical and nuclear cataracts, compared to median or high

levels. Vitale, et al. Epidemiology 1993 May;4(3):195-203

 

7. Smokers were 2.6 times as likely to develop posterior subcapsular

cataracts than nonsmokers. Hankinson, et al. JAMA 1992 Aug 26;268(8):994-8

 

8. Patients with senile cataracts were found to have significantly lower

blood and intraocular levels of the mineral selenium than controls. Karakucuk

S, et al. Acta Ophthalmol Scand 1995 Aug;73(4):329-32

 

9. Alpha lipoic acid can help prevent cataract formation as well as nerve

degeneration and radiation injury. Packer, et al. Free Radic Biol Med 1995

Aug;19(2):227-50

 

 

 

 

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RETINITIS PIGMENTOSA STUDIES

 

 

 

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1. Patients with retinitis pigmentosa appear to have faulty cellular

uptake of the amino acid taurine. Disturbed utilization of vitamin A also

appears to play a part in retinitis pigmentosa, and a subgroup of patients

benefit from supplementation of this vitamin. Head KA, Altern Med Rev 1999

Oct;4(5):342-59

2. The essential fatty acids alpha-linolenic acid and DHA may be required

for those with retinitis pigmentosa to support normal functional development of

the retina. Uauy R, et al. Lipids 1996 Mar;31 Suppl:S167-76

 

3. A diet high in polyunsaturated fats (e.g. corn oil), and low in

vitamin E, selenium, sulfur-containing amino acids (e.g. taurine, methionine),

and chromium were related to a build up of pigment which mimics one type of

retinitis pigmentosa. Katz, et al. Invest Ophthalmol Vis Sci 1978

 

4. Lutein supplementation in high doses improved both visual acuities and

visual fields after 2-4 weeks of treatment in 16 subjects, and was especially

effective in blue eyed individuals. Dagnelie G., et al Optometry 2000

Mar;71(3):147-64

 

 

 

 

DISCUSSION AND COMMENTS

 

While these studies are certainly promising, we must stress that there are

no widely accepted or proven cures for degenerative eye disease and some studies

have even shown no positive results. (This often can be attributed to their use

of the wrong form of nutrients or inadequate doses). More studies are indicated

and being undertaken at centers all over the world. A few small, nonpublished

studies have shown that as many as 80% of early macular degeneration patients

have stablized for several years after beginning supplements, but these are

still preliminary.

Other factors affect the progression of eye diseases, including too many

saturated and " trans " (hydrogenated) fats and not enough Omega 3 fats. Also

certain medications, toxins (including aspartame, aka " Nutrasweet " click for

article, and MSG), smoking, excess sunlight exposure, poor drinking water and

air quality, as well as lack of exercise and the resultant decreased blood flow

to the ocular tissues can affect visual outcome. (See our " Tips " report on The

EYE SITE's Home Page for more on these other factors.)

 

The overwhelming body of evidence points to significant beneficial effects

of nutritional supplementation for most degenerative eye conditions. Important

to remember is that most of the above studies used blood levels and food intakes

associated with a normal diet. Taking supplements with dosages significantly

higher than available in a normal diet may have a much more protective effect

than dietary levels alone. With so little risk, and the other potential health

benefits from taking nutritional supplements, it would certainly seem prudent to

try them, especially for macular degeneration where there are no real options.

 

Once the damage is done it cannot be reversed (except to a small degree),

so prevention and early intervention is essential, especially if we have a

family history of the disease. Of course, it's important to slow further

progression at any stage of development. It is also important to be followed

closely by a nutritionally knowledgeable eye doctor when starting nutritional

supplements and one should never discontinue prescribed medications without your

regular doctor's approval.

 

Most of the nutrients mentioned above can be purchased individually or in

combination at your local healthfood store, but it can be very confusing for the

lay person or even health professionals to separate the facts from the hype.

For this reason, we've compiled a Comparison Chart for the two best ocular

nutrition supplements which we've come across, as well as the two most popular

brands given away as samples by many eye doctors. Forget the hype and compare

them head-to-head yourself by going to the Ocular Nutrition Comparison Chart by

clicking on this underlined text.

 

 

 

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May we count on you to help us? Since the vast majority of optometrists

and ophthalmologists find it very difficult to keep up with all the new

research, would you please share this information with your own eye doctor?

(Emailing or printing this page out and handing or faxing it to him/her are the

best ways.) We know that, with your help, we can reach more eye doctors and

keep them up-to-date on promising new techniques for preserving eyesight and

health. We also would appreciate your requesting that other health websites you

visit link to our studies. We thank you in advance for your kind efforts!

 

 

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