Both doctors and the public have
shown growing interest in the relationship between diet
and health. Good nutrition depends on a healthy mixture
of proteins, carbohydrates, fats, vitamins and minerals.
Protein is needed for the building blocks and chemical
machinery of our bodies; carbohydrates are needed for
immediate fuel and energy; fats are needed for long
term storage of fuel and energy. Vitamins are organic
compounds that our bodies cannot manufacture but are
essential for maintaining good health. The eye, like
any other part of the body, benefits from a healthy
diet. Although the exact causes of macular degeneration
are not understood, there is some evidence that vitamins
and minerals may play a preventive role.
Macular degeneration is damage or breakdown of the
macula, the small part of the retina responsible for
central vision. It affects both distance and close vision
and can make some activitiesÐlike threading a needle
or readingÐvery difficult or impossible. Macular
degeneration is the leading cause of severe visual loss
in people over 65.
Zinc, one of the most common minerals in our body,
is very concentrated in the eye, particularly in the
retina and macula. Zinc is necessary for the action
of over 100 enzymes, including chemical reactions in
the retina. Studies show some older people have low
levels of zinc in their blood. Because zinc is important
for the health of the macula, some think that supplements
of zinc in the diet may slow down the process of macular
degeneration. Scientific studies are not complete and
there is no agreement concerning the value of zinc supplements.
It is possible that too much zinc may interfere with
other trace minerals such as copper.
Normal chemical reactions from light in the eye activate
oxygen that may cause macular damage. Some vitamins
function as antioxidants that work against this activated
oxygen. It may be claimed that antioxidant vitamins
(vitamins A, C and E) can help slow down macular degeneration
and other aging problems. As in the controversy over
zinc, there is no agreement that these antioxidants
actually help macular degeneration.
The first step to overall good health is a balanced
diet. Vitamins and minerals are commonly given as supplements
to the diet in amounts determined by recommended daily
allowances. These supplementary dosages cause no apparent
harm and are commonly available. Large doses of vitamins,
called therapeutic doses, in amounts many times the
recommended daily allowances, may not be completely
safe.
Nutrition and macular degeneration is still being researched.
Consultation with your ophthalmologist before beginning
to take therapeutic doses of any vitamin or mineral
is advisable. |