Nutritional Supplements and Age-related Macular Degeneration – Focus on Omega-3 Fatty Acids
consumption was associated with a reduced risk of neovascular AMD (OR 0.32, p=0.03 and OR 0.29, p=0.02, respectively). Moreover, consumption of oily fish at least once per week halved the risk of neovascular AMD compared with consumption less than once per week (OR 0.47, p=0.002).55
The US Twin Study of Age-related Macular Degeneration A US comparison study of 221 twins with AMD and 459 twins with no AMD signs found that intake of ω-3 fatty acids was inversely associated with AMD (OR 0.55).56
The reduction in the risk of AMD with
a higher intake of ω-3 fatty acids was seen primarily among subjects with low levels of ω-6 fatty acids. In addition, increased fish consumption reduced the risk of AMD, particularly for two or more servings per week (OR 0.64).
Age-related Eye Disease Study
Although the AREDS nutritional supplement does not contain ω-3 fatty acids, the dietary information supplied by the AREDS population has been examined in order to determine a link between ω-3 fatty acids and AMD. Total dietary ω-3 PUFA intake was inversely associated with the incidence of neovascular AMD at baseline (OR 0.61, p<0.01) in 4,519 participants. This inverse relationship was even more significant when specifically examining the higher versus lower consumptions of DHA (OR 0.54, p<0.004). The inverse association was also observed with high fish consumption (OR 0.61, p<0.01).57 AMD progression over median follow-up greater than six years was inversely related to EPA (OR 0.44) or EPA + DHA (OR 0.45) consumption in 2,132 participants from the AREDS population.58
Moreover, in a nested cohort study of
1,837 individuals from the AREDS population, those participants at moderate to high risk of AMD progression and with the highest intake of DHA, EPA or DHA + EPA were approximately 30 % less likely to progress over 12 years than their peers.59,60
In a study of 2,924
participants in the AREDS trial over eight years, higher intakes of DHA and EPA were associated with a lower risk of AMD progression (OR 0.73 and 0.74, respectively), independently of consumption of the AREDS supplement.61
Women’s Health Study
A recently published study has provided further evidence to support a role for ω-3 PUFAs in the prevention of AMD in women. Of 39,876 female health professionals enrolled in the Women's health study, 38,022 women without a diagnosis of AMD completed a detailed food-frequency questionnaire at baseline. The primary endpoint was incident AMD causing a reduction in best corrected visual acuity to 20/30 or worse, as identified by self-report and confirmed by medical record review. During the follow-up (average duration 10 years), there were 235 confirmed cases of AMD. Compared with women in the lowest tertile of DHA intake, those in the highest tertile had a reduced risk of AMD (OR 0.62). A similar finding was observed for EPA intake (OR 0.66). A reduced risk was also seen in women who consumed at least one serving of fish per week versus those who consumed less than one serving per month (OR 0.58). This lower risk appeared to be mostly attributed to consumption of canned tuna fish and dark-meat fish.62
Other Studies
Additional studies have examined the associations between AMD, ω-3 fatty acid intake and consumption of fish. A risk reduction in AMD was associated with the highest levels of ω-3 intake (OR 0.85, p=0.03), but not with consumption of more than two servings of fish per week, in a
EUROPEAN OPHTHALMIC REVIEW
Table 2: Pooled Odds Ratios for Age-related Macular Degeneration Comparing the Highest with the Lowest Dietary Intake of Omega-3 Fatty Acids and Fish
Conditions and studies
Omega-3 fatty acids and late AMD Chua et al. Arch Ophthalmol 2006;124:981 Seddon et al. Arch Ophthalmol 2006;124:995 Seddon et al. Arch Ophthalmol 2001;119:1191 AREDS Arch Ophthalmol 2007;125:671 All studies
Fish and early AMD Delcourt et al. Eur J Clin Nutr 2007;61:1341 Chua et al. Arch Ophthalmol 2006; 124:981 Amasson et al. Am J Ophthalmol 2006; 142:419 Mares-Perlman et al. Arch Ophthalmol 1995;113:743 Heuberger et al. Arch Ophthalmol 2001;119:1833 Cho et al. Am J Clin Nutr 2001;73:209 All studies
Fish and late AMD Chua et al. Arch Ophthalmol 2006; 124:981
Mares-Perlman et al. Arch Ophthalmol 1995;113:743 Heuberger et al. Arch Ophthalmol 2001;119:1833 AREDS Arch Ophthalmol 2007;125:671 Seddon et al. Arch Ophthalmol 2006;124:995 Seddon et al. Arch Ophthalmol 2001;119:1191 All studies
OR (95 % CI high vs. low intake
0.44 (0.08–2.39) 0.55 (0.32–0.95) 0.75 (0.44–1.26) 0.61 (0.41–0.90) 0.62 (0.48–0.82)
0.64 (0.31–1.31) 0.62 (0.38–1.02) 0.61 (0.38–0.98) 0.90 (0.60–1.30) 1.00 (0.70–1.40) 0.65 ((0.46–0.91) 0.76 (0.64–0.90)
0.25 (0.06–1.02) 0.80 (0.20–2.50) 0.40 (0.20–1.20) 0.61 (0.37–1.00) 0.64 (0.41–1.00) 0.86 (0.58–1.27) 0.67 (0.53–0.85)
AMD = age-related macular degeneration; CI = confidence interval; OR = odds ratio. Adapted from Chong et al., 2008.67
population of 6,734 individuals.63
In a sample of 2,520 individuals, those with advanced AMD were less likely to consume fish or shellfish high in ω-3 fatty acids (OR 0.40). There was no relationship between AMD and consumption of crab and oysters, which have high levels of zinc.64
In a US study, higher intake of specific types of fat, including vegetable, monounsaturated, PUFAs and linoleic acid, rather than total fat intake, was found to be associated with a greater risk of advanced AMD. Diets high in ω-3 fatty acids and fish were associated with a lower risk of AMD only in individuals with low intake of the ω-6 fatty acid linoleic acid.51
The third National Health and Nutrition Examination Survey (NHANES III) found associations between fat intake and AMD in a cross-sectional study. Consumption of fish more than once a week compared with once a month or less was associated with a reduced risk of early ARM (OR 1.0) and late ARM (OR 0.04, p=0.10).65
The Pathologies oculaires liées à l'âge [Ocular pathologies linked to age (POLA)] study recently assessed the association of dietary fat with the risk of AMD in 832 patients. Total PUFA was not significantly associated with AMD (OR 1.02), but fish intake (more than once a month versus less than once a month) was associated with a 60 % reduction in risk of AMD (OR 0.42, p=0.01).66
Meta-analyses
In a meta-analysis of nine studies and 88,974 participants, high dietary intake of ω-3 fatty acids was inversely associated with the risk of late AMD (OR 0.62) (see Table 2).67
Moreover, fish consumption at least
twice a week was associated with a reduction in both early (OR 0.76) and late (OR 0.67) AMD (see Table 2).
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