Reflections on sight loss - RNIB

Eye health
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Oily fish is useful because it is usually the best
dietary source of Omega 3 fatty acids. The
specific AMD link was the subject of another
study from same University of Melbourne
team, published in Archives of Ophthalmology
last June, which found that eating a diet rich
in Omega 3 acids could reduce the likelihood
of developing the disease by 38 per cent.
They think that this is probably because those
fatty acids act to protect nerve cells, including
those in the retina.
The big link, for many, is with foods that
contain the ‘carotenoid’ anti-oxidants lutein
and zeaxanthin. “It’s logical that a diet rich in
those anti-oxidants should be shown to be
effective”, points out Professor Ian Grierson of
Liverpool University. “Lutein and zeaxanthin
protect the macula and come exclusively from
the diet.” In fact, unlike other dietary
carotenoids, these selectively accumulate in
the retina to make up the yellow screening
pigment in the macula. “If someone with early
AMD takes these anti-oxidants, they can slow
down the development of their disease,
particularly if it is the ‘dry’ form of AMD – for
which there is no other treatment as yet”,
Grierson adds. Green leafy vegetables are
most frequently cited as a good source; but
eggs are also a particularly good source of
lutein. It’s also crucial, Grierson stresses, to
remember that that these anti-oxidants will
not be absorbed without some fat – which is
why one egg is actually a much more effective
way to get lutein into the body than a much
bigger pile of steamed spinach.
A whole diet
Yet even these studies are still at a fairly early
stage, points out Adnan Tufail, consultant in
medical retina at Moorfields. “I don’t
discourage patients who want to consume
more lutein or zeanthin – unless they have
conditions like retinal dystrophy, which can
actually be made worse; but I don’t actively
encourage them either.” Tufail is embarking on
a wider study into nutrition and sight.
Equally, specialists like Grierson who do link
diet to eye health stress that diet alone
cannot eliminate absolutely everyone’s chance
of developing AMD. “When you tackle risk
factors, unfortunately that does mean that not
everyone is going to benefit. Some people’s
risk is simply too high in the first place”, says
Grierson. “What we do know is that across the
population, tackling diet works to reduce the
incidence of AMD.”
The issue on which both camps do agree is
that a ‘healthy diet’ is sadly lacking across a
lot of the UK.
Links
➜ Five a day: www.5aday.nhs.uk
Eggs explained
Eggs have been the subject of much bad
press over the years, and many people still
avoid them on the basis that they contain
cholesterol. However, specialists including
the British Heart Foundation now agree
that it’s saturated fat in general (from fatty
meat and full-fat dairy) that affects
cholesterol levels. In fact the foundation
dropped its recommendations to limit eggs
to three a week back in 2007. As Professor
Grierson says, the small amount of fat that
eggs do contain makes them a very
effective vehicle for lutein.
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