Eat right to keep your eyes, brain and heart healthy
Homocysteine, an amino acid believed to contribute
to heart attack, stroke and dementia, likely also is a player in retinal damage
and vision loss, researchers say. Scientists want to know the impact of
resulting elevated homocysteine levels on the extensive blood vessel and
neuronal network of the retina; their preliminary evidence suggests that it
isn’t good. The retina is the tissue at
the back of the eye that collects light signals to send to the brain for
processing as vision.
Homocysteine levels rise when folic acid levels
drop, a common problem for people whose diets are poor in folate-rich fruits, tomatoes,
vegetables and grains
Folate and vitamin B12 – which we typically get plenty of – convert
homocysteine to methionine, an amino acid essential to protein synthesis.
Without the conversion, rising homocysteine levels interfere with the folding
and structure of collagen, a component of bone, tissue and the basement
membrane of blood vessel walls. When pregnant women don’t get enough folate,
the result can be devastating neural tube defects, such as spina bifida, in
their babies. People with a genetic defect that results in a homocysteine level
40 times the norm are tall, thin, have osteoporosis and a markedly increased
risk of clotting. Tiny clots cause small, frequent strokes, cumulative tissue
damage and, eventually, mental retardation. If you are having thrombotic
attacks in the retina like what happens in the brain, it will affect visual
function, too.
To avoid the build-up of homocysteine, we need to eat plenty of folate-rich
fruits, tomatoes, vegetables and whole grains; things that are in the Mediterranean
diet. Just like this diet will help your
heart and blood vessels, it will be good for your eyes, and help protect your
good vision for a lifetime.