Macular Degeneration
Vitamins - High doses of certain dietary
supplements provide the first effective
treatment for the leading cause of vision loss
among the elderly, a new nationwide clinical
study has concluded.
The disease, macular
degeneration, destroys the central portion of
the retina, the light-gathering cells at the
back of the eye. Among people who already have
significant yellowish deposits accumulating at
the back of their eyes — the hallmark of the
disease — the supplements cut their risk of
vision loss by one-fifth.
The macular
degeneration vitamin supplements — a
combination of zinc and the antioxidants
vitamin C, vitamin E and beta-carotene — did
not appear to slow the early stages of the
disease, when the yellowish deposits develop,
but that is a normal part of aging and is not
necessarily of concern. Almost everyone over
age 70 has at least one or two of them.
As the disease
progresses, the center of the field of view
begins to blur, making it difficult to read,
drive and recognize faces. Victims must rely
on their peripheral vision, looking out of the
corners of their eyes and missing much of the
color and detail.
Glaucoma and
cataracts strike more people than macular
degeneration, but effective treatments exist
for those diseases. This is the one disease
for which there was nothing prior to this. At
best, laser surgery can slow down the growth
of abnormal blood vessels in the most severe
cases of macular degeneration.
Earlier studies had
indicated that people who eat large amounts of
fruits and vegetables, which contain vitamins
and beta-carotene, are at lower risk of
developing macular degeneration. An earlier,
smaller clinical study had suggested zinc
might be helpful.
Among those whose
disease had progressed to the intermediate
stage, the zinc supplements reduced by 11
percent the risk of the disease progressing to
the advanced stage, and the antioxidants
reduced the risk by 10 percent. When the two
were combined, the risk dropped by 19 percent.
The study followed the participants for 6.5
years on average.
The daily dosages of
the antioxidants used in the study were 500
milligrams of vitamin C, 400 IU of vitamin E
and 15 milligrams of beta-carotene, a molecule
that provides the color of carrots and sweet
potatoes. The body converts the beta-carotene
into vitamin A. The daily dosage of zinc was
80 milligrams with 2 milligrams of copper.
High levels of zinc can cause a deficiency of
copper in the body, which can lead to anemia.
Those amounts are
well above the usual levels recommended by the
Food and Drug Administration: three times as
much vitamin A, eight times as much vitamin C,
13 times as much vitamin E and five times as
much zinc.