27
Modifiable risk factors for AMD
a 38% reduction in risk for AMD in subjects with high
dietary long-chain omega 3 PUFA
(55)
. By contrast, two
recent studies found an increased risk for ARM in sub-
jects with high omega 3 PUFA
(56-57)
. However, in these
studies, only total omega 3 PUFA intake was studied,
including ALA and long-chain omega 3 PUFA, while
most studies found a reduced risk for ARM only with
high long chain omega 3 PUFA, in accordance with the
scientific rationale. As stated in one of these studies
(57)
,
the main source for ALA is vegetable oil, which is also
the main source of omega 6 PUFA, and was found to
increase the risk for ARM in some studies
(43,53)
. Future
studies need to separate the precursor from the long
chain derivatives.
Globally, available epidemiological studies strongly
suggest a reduced risk for AMD in subjects with high
consumption of long chain omega 3 fatty acids and
fish.
In addition, some studies have suggested that the risk
for AMD may be decreased in subjects with high intake
of vitamins B
(56-63)
. Consistently, supplementation with
0
1
2
Blue
Mountains
Nurses and
Physicians'
Health
Reykjavik Seddon et al.
AREDS
Figure 4. Association of the risk for AMD with dietary long chain omega 3 or fish (prospective studies). References of the cited studies: Blue
Mountains
(51)
; Nurses and Physicians’Health Study
(50)
; Reykjavik Study
(52)
; Seddon et al.
(53)
; AREDS
(54)
vitamins B reduced the incidence of AMD in a random-
ized interventional study
(64)
. A role for vitamin D in the
aetiology of AMD has also been suggested
(65)
.
4. Light exposure and cataract
extraction
Sunlight exposure has been investigated as a potential
risk factor for AMD. Light exposure may have deleteri-
ous effect on the eye, in particular through the produc-
tion of reactive oxygen species
(66)
. Only blue light reaches
the retina, since ultraviolet radiations are absorbed by the
cornea and the lens. Intense blue light exposure has been
shown to induce retinal damage
(66)
, and the macular pig-
ment, which absorbs blue light, is thought to protect the
macula against photo-toxic damage
(30)
. However, results
have been inconsistent in the few studies that have inves-
tigated the associations of the light exposure with AMD
in humans
(27,67-74)
. Globally, the available studies suggest
that the effect of sunlight exposure in the aetiology of
