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Macular Degeneration. The Preventive Role of Nutraceuticals (Updated July 2010)

The Condition
The Shift
Comments
Conclusion
Lexicon
More Info

The abbreviations (L) or (A) after a word indicate a link to the lexicon or to the abstract page

THE CONDITION :

Among the elderly Macular degeneration (L) is a frequent condition :

"If left untreated, without prophylactic measures, 7.5 million American adults will suffer vision loss from Age-Related Macular Degeneration (ARMD) by the year 2020 (Richer SP. 1993) (A)"

In 1993, there was no proven form of treatment for macular degeneration :

"Unfortunately, no proven form of treatment is currently available for the dry, atrophic form of ARMD seen in more than 90 percent of patients with this condition. (van der Hagen AM. 1993) (A)"

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THE SHIFT : The Shift Toward Nutraceuticals

In 1993-1994, some researchers suggest the use of nutraceuticals (L).

"A recent theory suggests that ARMD is associated with damage to the retina caused by free-radicals (L). If this is correct, it is possible that the damage could be prevented or moderated by supplementing the diet with specific anti-oxidants (L), vitamins and minerals that enhance the body's natural defenses against free radicals. (van der Hagen AM. 1993) (A)"

"Oxidative mechanisms are believed to play an important role in the pathogenesis (L) of age-related eye disease, in particular, cataract (L) and macular degeneration, the two most important causes of visual impairment in older adults. For this reason, there is considerable interest in determining whether vitamins and trace minerals with antioxidant properties can be of benefit in preventing the onset or progression of disabling eye disease. ..."

and:

"Thus, reliable data regarding a potentially important benefit of vitamin supplements in eye disease will emerge mainly from well-designed, large-scale, randomized trials. Such data are already being collected in the National Eye Institute-sponsored Age Related Eye Disease Study, as well as in the Physicians' Health Study and Women's Health Study. (Christen WG Jr. 1994) (A)"

"The relationships between fasting plasma levels of retinol (L), ascorbic acid (L), alpha-tocopherol, and beta-carotene (L), and age-related macular degeneration (AMD) were studied in a population enrolled in the Baltimore Longitudinal Study of Aging (BLSA), in which most of the data were collected 2 or more years before assessment of macular status. The data suggest a protective effect for AMD of high plasma values of alpha-tocopherol (L). An antioxidant index, composed of plasma ascorbic acid, alpha-tocopherol, and beta-carotene, was also protective. The use of vitamin supplements to prevent AMD is not supported by these data, which showed no protective effect of vitamin use. (West S. 1994) (A)"

During the years' 1995-1996, confidence in nutraceuticals starts increasing, although with prudence :

"Micronutrient (L) supplementation is a provocative but largely unproved hypothesis. Positive associations of cigarette smoking and cardiovascular disease or certain risk factors for cardiovascular disease with age-related macular degeneration (AMD) provide potential clues as to the underlying pathogenesis of AMD and are yet another reason to treat these health problems. Drusen may disappear after laser to the macula; however, this intervention will require careful, randomized, prospective trials to determine if this therapy can reduce the risk of choroidal neovascularization and visual loss developing in patients with AMD.

CONCLUSIONS: It is reasonable to have individuals wear sunglasses for comfort and possible protection from ultraviolet light exposure to all ocular structures (especially the lens) at little or no risk to the patient. Physicians probably should be reluctant to prescribe micronutrients or suggest other interventions (such as laser to drusen) until their health claims have been substantiated and their long-term safety soundly established. (Bressler NM. 1995) (A) "

"The potential beneficial effects and adverse side effects of the nutritional supplements have not yet been fully evaluated in carefully conducted clinical trials. Several randomized placebo-controlled clinical trials are presently underway. Results of these studies will provide important data to clarify the potential beneficial and adverse effects of such treatment. Until these results are available, it would be premature to make recommendations in favor of vitamin or mineral supplements. (Chew EY. 1995) (A)"

"No proven preventive measures exist to halt development or progression of this disease. The specific insults that trigger and perpetuate age-related macular degeneration are unknown; however, it may be the result of repetitive oxidative injuries. Several studies suggest a possible protective role for antioxidant micronutrients and other trace minerals, but data for specific antioxidants have been inconsistent between studies. Although promising, the preliminary evidence is limited. Reliable data on whether antioxidant vitamins or trace minerals decrease the development or progression of age-related macular degeneration will emerge from several ongoing large-scale randomized clinical trials. Based on the currently available information, it is not possible to recommend antioxidant micronutrient supplementation to protect against development or retard progression of age-related macular degeneration. (Fekrat S. 1996) (A)"

"While results from several studies, primarily cross-sectional and case-control, are compatible with a possible protective role for micronutrients in disease development, data for specific nutrients or specific disease types have often been inconsistent. Further, these observational studies are limited because of the inherent imprecision of dietary exposure data and the likely effects of uncontrolled confounding. Thus, reliable data regarding a potentially important benefit of vitamin supplementation in eye disease will emerge mainly from well-designed, large-scale, randomized trials. (Christen WG. 1996) (A)"

During the same period (1995-1996), other researchers publish the first conclusive results of investigations concerning the beneficial effects of carotenoids, zinc, antioxidants, vitamin E, magnesium, vitamin B6 and folic acid."

"Epidemiological (L) data indicate that individuals with low plasma concentrations of carotenoids and antioxidant vitamins and those who smoke cigarettes are at increased risk for age-related macular degeneration ...."

and:

"The combination of 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 DM. 1995) (A)"

"The data (of the study to quantify relationships between dietary intake of zinc and antioxidant nutrients and early and late age-related maculopathy) are weakly supportive of a protective effect of zinc on the development of some forms of early ARM. Prospective studies are needed to further evaluate the potential influence of these and other nutritional factors on different types and stages of age-related macular degeneration. (Mares-Perlman JA. 1996) (A)"

"In a prospective 18 month, double-blind case-controlled study, the age-related macular degeneration population manifested decreased intake of nutrients vital to cardiovascular health: vitamin E, magnesium, zinc, vitamin B6 and folic acid. (Richer S. 1996) (A)"

In 1997, the inconclusive and negative publications concerning nutraceuticals disappeared from literature. Two most recent publications on the subject of Macular Degeneration indicate the utility of nutraceuticals and moderate wine consumption.

"The retinal carotenoids lutein and zeaxanthin, that form the macular pigment (MP) may help to prevent neovascular age-related macular degeneration. The purpose of this study was to determine whether MP density in the retina could be raised by increasing dietary intake of L and Z from foods.

CONCLUSIONS: Increases in MP density were obtained within 4 weeks of dietary modification for most, but not all, subjects. When MP density increased with dietary modification, it remained elevated for at least several months after resuming an unmodified diet. Augmentation of MP for both experimental and clinical investigation appears to be feasible for many persons. (Hammond BR Jr. 1997) (A)"

"Lutein is a unique dihydroxy-carotenoid (or Anthophyll) present in many plants consumed in the human diet.

In humans, as in plants, Lutein is believed to function in two ways: first as a filter of high energy blue light (Note added: the harmfull rays of ultra-violet light), and second as an antioxidant that quenches photo-induced free radicals and reactive oxygen species (ROS).

Epidemiologic evidence suggests that Lutein consumption is inversely related to eye diseases such as age-related macular degeneration (AMD) and cataract. This is supported by the finding that lutein (and a related compound, zeaxanthin) [Note added: zeaxanthin is a stereochemical isomer of lutein] are specifically and selectively deposited in the macula lutea, an area of the retina responsible for central and high acuity vision.

Macular pigment, a yellow color in the center of the macula, functions as a filter of the high energy blue light that protecting its sensitive rods and cones, and is comprised solely of lutein and zeaxanthin.

Human inervention studies show that Lutein supplementation results in increased macular pigment. This suggests that lutein supplementation may protect against SAMD. There is also evidence suggesting that lutein may have a protective effect against other chronic diseases, such as certain cancers and cardiovascular disease. However, further research is needed to determine optimal lutein doses. (Andrew Shoa, PhD 2001)(A)"

"Moderate wine consumption is associated with decreased odds of developing age-related macular degeneration (AMD). Health promotion and disease prevention activities directed at cardiovascular disease may help reduce the rate of (AMD)-associated blindness among older people.(Obisesan TO. 1998) (A)"

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COMMENTS :

The above publications on Macular degeneration demonstrate the general shift in favor of nutraceuticals.

A shift of interest for a therapeutic or a preventive approach of a health condition is first perceptible at research level as demonstrated above.

Usually, it takes five to ten years for a shift at research level to permeate into the medical establishment. It might take that long before nutraceuticals will be routinely prescribed to slow down macular degeneration and what is more important, to prevent its occurrence.

Recommendations From the Longevity Institute : 40 milligrams of Lutein daily

In addition toits own research, the recommendation of the Longevity Institute is based on a publication indicating that 40 milligrams of Lutein paer day during 9 weeks has been found to improve visual acuity in patients with macular degeneration (Dagnelie G, 2000).

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CONCLUSION :

The discovery of the role of lutein brings hope for the 7.5 million American adults that could suffer vision loss from Age-Related Macular Degeneration by the year 2020.

They are no longer without prophylactic measures. People that will reach 60 years of age around 2020 are now in their thirties. The earlier they start prevention, the better they shall protect their vision.

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LEXICON : Lexicon of the Technical Terms Used in Newsletter2

Alpha-tocopherol
Synonym for vitamin E. [ Back to text ]

Anti-oxidant
A substance that slows down the oxidation of other substances, thus, helping reduce their deterioration. [ Back to text ]

Ascorbic Acid
Synonym for vitamin C. [ Back to text ]

Beta-carotene
The main provitamine A. Provitamins A are substances that after absorption in the gut, are modified by enzymatic reaction to yield vitamin A. [ Back to text ]

Cataract
Opacity of the lens of the eye, causing sight distortion progressing to blindness. [ Back to text ]

Epidemiology
The branch of Medicine that investigates the causes and control of diseases. [ Back to text ]

Free-radical
An atom or molecule having at least one unpaired electron: Free redicals are usually reactive and unstable. [ Back to text ]

Macular Degeneration
A condition in which the retina of the eye progressively loses its ability to register light. The condition primarly affects the central part of the retina. [ Back to text ]

Micronutrient
Any of the chemical elements, such as iron, selenium etc, required in minute quantites to assume health. [ Back to text ]

Nutraceutical
Nutraceuticals are nutrients with preventive or curative properties. [ Back to text ]

Pathogenesis
What is related to the origin or the progress of a disease. [ Back to text ]

Retinol
Synonym for vitamin A. The term retinols also defines all vitamin A derivative compounds. [ Back to text ]

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MORE INFO :

See the excellent graphical and scientific information about Macular Degeneration developed for the N.J.O.A. by Christopher J. Quinn, O.D.

The American Academy of Ophtalmology recommends zinc and anti-oxidants against macular degeneration.

Search the Web with Alta Vista on the subject of macular degeneration.

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