24
mostly in favour of a protective role of antioxidants
for AMD
(24)
. Moreover, the Age-Related Eye Diseases
Study (AREDS), a randomized clinical trial performed
in the United States and including on almost 5000
subjects supplemented for five years, showed a signifi-
cant 25% reduction of the incidence of late AMD with
supplementation in antioxidants and zinc, by compari-
son with placebo
(25)
. In this field, data from the United
States should be extrapolated to European popula-
tions with caution. Indeed, vitamin supplements are
widely used in the American population, while this is
rarely the case in Europe. For instance, two thirds of
the AREDS participants used vitamin supplements, in
addition to the supplementation tested in the study
(25)
.
Plasma vitamin C concentration at baseline in the
AREDS (before the initiation of the study supple-
mentation) was 62 micromol/l
(25)
, whereas it was 31.6
micromol/l in men and 40.5 micromol/l in women of
the Pathologies Oculaires Liées à l’Age (POLA) Study,
performed in the South of France
(26)
. Similarly, in the
EUREYE Study, plasma vitamin C concentrations
ranged from 35.5 micromol/l to 48.4 micromol/l in
seven European countries
(27)
. Therefore, antioxidant
intake is much lower in European populations than
in the United States, with part of European popula-
tions being at risk of clinical deficiency in these vita-
mins. Two European studies suggested that the benefit
to be expected from increased antioxidant intake may
be more important in our populations with low anti-
oxidant intake. Indeed, in the French POLA Study, we
observed an 80% decreased risk for late AMD in the
subjects with higher plasma vitamin E, by comparison
to those with lower concentrations
(28)
, a much stronger
effect than the 25% reduction in risk observed in the
AREDS Study. Moreover, we observed a 25% reduc-
tion in risk for early ARM, whereas the AREDS Study
showed no benefit of antioxidant supplements for early
ARM. Similarly, results from the Rotterdam Study
0
1
2
Beaver Dam EDCC NHANES III Gale et al.
POLA
Figure 1. Association of the risk of AMD with plasma levels of lutein and zeaxanthin in cross-sectional and case-control studies (odds-ratios with
95% confidence interval)
OR below 1 suggest a protective role and OR greater than 1 suggest a deleterious role. References of the cited studies: Beaver Dam
(31)
; EDCC
(32)
;
NHANES III
(33)
; Gale et al
(34)
; POLA
(35)
