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THE SHIFT : The Shift
Toward Nutraceuticals
In 1993-1994, some researchers suggest to 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 disappear from the literature.
The two most recent publication 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 human as in plants, lutein is believed to function in two ways: first as a filter of high energy blue
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 toeye 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 protects the sensitive rods and cones, and is comprised solely of
lutein and zeaxanthin.
Human inervention studiesshow 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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The Condition
