Ocular Nutrition
Everyone knows that
carrots are good for
your eyesight. But
why is that? And are
there any other foods
we should recommend
to our patients for
promoting eye health?
We examine 5 popular
foods claimed to
improve eye health.
Carrots
Carrots contain lutein and beta-
carotene, a substance converted to
vitamin A by the body. Vitamin A is an
essential nutrient for cell growth and
ocular development. A lack of vitamin
A leads to night-blindness, retinal
scarring and blindness. Worldwide, an
estimated 250,000 to 500,000 children
become blind every year due to vitamin
A deficiency and half of them die within
12 months of losing their sight. 1
Beta-carotene was part of the original
AREDS formula 2 but the AREDS2 study 3
found that Lutein and Zeaxanthin have a
bigger role to play in AMD management
and should replace beta-carotene in
future formulae. High levels of beta-
carotene taken as a supplement were
shown to double the risk of lung cancer
in smokers. 4
Our Verdict: A lack of carrots is
bad for your eyesight.
10
etCETera | January 2017
Egg Yolks
Egg yolks contain high levels of lutein
and zeaxanthin. 5 Both these yellow-
pigmented antioxidants belong to a class
of compounds called carotenoids. Lutein
and zeaxanthin selectively accumulate
in the macula of the retina, scavenging
free radicals and acting as a blue-light
filter. 6 Low plasma levels of lutein and
zeaxanthin are associated with an
increased risk of age-related macular
degeneration (ARMD). 7
Some experts suggest that we need
about 6 mg of these antioxidants a day.
One egg yolk has about 0.25 mg of lutein,
more than most fruits. 8 The body absorbs
lutein found in egg yolks more easily than
it does that found in fruits or vegetables. 9
Our Verdict: Egg yolks have
surprisingly high levels of bio-
available lutein and zeaxanthin.
Spinach
Spinach, like many green, leafy
vegetable contains lots of lutein (7mg
per serving) but little or no zeaxanthin.
Consuming it raw and whole is best,
chopping 10 and heating 11 spinach
is known to damage some of its
antioxidants. While the levels of lutein
are significantly higher than in egg
yolks, the bioavailability is thought
to be lower. 5
Kale, broccoli, romaine lettuce,
peas, brussels sprouts, courgette, and
other collard greens also contain high
amounts of lutein. 5
Our verdict: Leafy green
vegetables are a must for ocular
health and for a balanced diet.
Blueberries
Blueberries, also referred to as
“brainberries,” are considered by some to
be the healthiest food on the planet. They
contain high concentrations of vitamins,
A, C, E and Zinc, the ingredients in the
original AREDS formula. 2
In theory, antioxidants should protect
the retina and other tissues such as the
lens against photochemical damage
from sunlight but there is little or no
scientific research linking blueberries
to improvements or maintenance
of ocular health.
Our verdict: We love blueberries
but the science behind their ocular
benefits is poor
Figure 1 Lutein & zeaxantin are thought
to help delay the progression of AMD