Can
This Supplement
Preserve Your Eyesight?
If
you read newspapers or watch TV, you may have been led to think
that age-related macular degeneration (AMD) can now be prevented.
AMD is a major cause of severe vision problems and blindness
among older people, particularly those over 75. It starts as
a distortion in the visual field, progressing to a "hole"
in the macula, a spot at the center of the retina. Nobody knows
what causes it, and there is no cure or even any effective treatment
so far.
Many
supplements claim to benefit eyesight, but recently one called
Ocuvite PreserVision has emerged as a possible treatment for
AMD. It contains zinc and copper (the latter to offset the copper
deficiencies caused by zinc supplementation), vitamin C and
E, and beta carotene. Some formulations, marketed as Ocuvite
Lutein, contain additional carotenoids.
Manufactured
by Bausch & Lomb, which has a good reputation in the eye-care
field, Ocuvite PreserVision was used last year in a major study
called the Age-Related Eye Disease Study (AREDS), funded by
the National Eye Institute and published in the Archives
of Ophthalmology. This study found that in those already
diagnosed with AMD, the supplement reduces the risk of AMD progressing
to blindness.
Food
and eyesight
It
is well known that several nutrients help protect vision. The
old story that carrots are good for your eyes has turned out
to be true. Beta carotene, plentiful in carrots and many other
fruits and vegetables, is essential to good eyesight. Recently,
researchers have found that the retina actually contains beta
carotene as well as two other carotenoids, lutein and zeaxanthinpigments
that protect the retina from ultraviolet rays. Lutein and zeaxanthin
are found in many foods, including corn, dark leafy greens,
sweet peppers, squash, pumpkin, and red grapes. Vitamins C and
E, also found in plant foods, may be protective, too. Zinc also
occurs in high concentrations in healthy retinal tissue. Zinc
deprivation can result in blindness in animals and humans. For
all these reasons you need a varied diet rich in fruits and
vegetables, and including fish and small amounts of meat (for
zinc). A daily multivitamin/mineral pill is also a good idea,
particularly for vegetarians. Supplements specifically designed
for the eyes are another story.
Ocuvite
and eyesight
The
AREDS study was sound, and its findings encouraging. Over 3,600
people aged 55 to 80 were enrolled and followed for six years.
All were at high risk for AMD-related blindness: all had at
least some symptoms; some had advanced disease in one or both
eyes. One group took a formulation specially prepared for the
study (later marketed as Ocuvite PreserVision) with zinc and
antioxidants (C, E, and beta carotene); another group took zinc
alone; another the antioxidants alone; and still another a placebo.
Those who took zinc alone reduced their risk of AMD progression
by 21%, those taking only antioxidants had a 17% reduction in
risk, and those taking the combination reduced their risk by
25%.
However,
the researchers did not recommend that everybody take this supplement.
High doses of zinc can interfere with immune function,
impair the formation of red blood cells, and lower beneficial
HDL cholesterol. In addition, nobody knows what the long-term
effects of various carotenoid supplements may be. It is known
that beta carotene pills may increase the risk of lung cancer
in smokers. The people in the study already had symptoms of
AMD. There's no evidence that Ocuvite or any other supplements
can prevent the disorder.
Bottom
line: If you are over 55, get regular dilated eye exams and
ask about your risk of developing AMD. If your optometrist or
ophthalmologist diagnoses you as having AMD symptoms, by all
means consider taking a supplement of zinc and antioxidants
such as Ocuvite PreserVision. But tell your doctor all the supplements
you are taking. Some of them may contain vitamin C or E or zinc,
and you could end up getting too much if you start taking an
eye supplement. The daily 4-pill dose of Ocuvite PreserVision
contains 70 milligrams of zincwhich is already a lot,
since the safe upper limit is 40 milligrams a day, according
to the Institute of Medicine. It also supplies 450 milligrams
of vitamin C, 400 IU of vitamin E, 28,600 IU of beta carotene,
and almost 2 milligrams of copper. A month's supply costs about
$16.
If your eyes are healthy, don't take this supplement on your
own, "for good measure." It is not known to prevent
AMD, only to slow its progression. And its high levels of zinc
may be dangerous.
Reference Source 98