Associations between Antioxidant and Zinc Intake and the 5-Year Incidence of Early Age-related Maculopathy in the Beaver Dam Eye Study

Abstract

Associations between antioxidants and zinc and the 5-year incidence of early, age-related maculopathy (ARM) were investigated in a population-based cohort of middle-aged and older adults participating in the Beaver Dam Eye Study in Beaver Dam, Wisconsin. A food-frequency questionnaire was administered at baseline (1988-1990) to collect dietary information for that time period and a period of time 10 years earlier (1978-1980) from a 50 percent random sample of persons participating in this study. The incidence of the specific lesions of larger drusen (>125 microns) and pigmentary abnormalities and the incidence of any ARM were assessed by masked grading of stereoscopic color fundus photographs in 1,709 persons who participated in 5-year follow-up eye examinations. Significant, but modest, inverse associations (p < 0.05) were observed between intakes of pro-vitamin A carotenoids and dietary vitamin E and the incidence of large drusen and between zinc and the incidence of pigmentary abnormalities. No significant inverse associations were found between antioxidant or zinc intake and the incidence of overall early ARM. If ARM, which is characterized by a broad spectrum of lesions, involves a number of different underlying pathophysiologic processes, then associations between specific antioxidants and the incidence of distinct macular lesions may be biologically important. However, because there were too few incident late ARM cases in this cohort, the authors were unable to assess whether antioxidant intake is associated with the progression of early ARM to late-stage macular degeneration. Clinical trials and longer-term prospective studies are needed to elucidate further the impact of antioxidants and zinc on the development and progression of ARM.

Review of nutrient actions on age-related macular degeneration

“…22 demonstrated an association between the high intake of β-carotene and vitamins C and E, as well as a reduced likelihood of neovascular AMD [20]. A meta-analysis published by Chong et al of randomized controlled trials reported an odds ratio of 0.75, which was obtained by pooling the results from two studies: the Rotterdam eye study [46] and the Beaver Dam eye study [40,47]. The results from subsequent meta-analyses performed by Chong et al [40] and by Evans and Lawrenson [35] did not support a specific role for vitamin E in the prevention of AMD.…”

“…Subsequently, the results of several studies disputed the role of zinc in AMD susceptibility [58]. However, results from the Beaver Dam Eye Study confirmed a weak protective effect of zinc on some forms of AMD [45], with no overall association with early AMD [47]. Subsequently, Klein et al reported a weak association between late AMD and the incidental use of vitamins A, C, and E and zinc [41].…”

Conceitos atuais e perspectivas na prevenção da degeneração macular relacionada à idade

“…Concluíram que as relações entre estes carotenóides e DMRI podem ser influenciadas pela idade e raça e requer posteriores avaliações em populações separadas e estudos prospectivos (71) . Similarmente a este relato, outros importantes estudos também não verificaram associações entre dieta de luteína e zeaxantina e prevalência de DMRI inicial ou tardia (72)(73) .…”

“…A ingestão diária de zinco exerce um efeito protetor para a gênese da DMRI precoce (89) . Um estudo prospectivo, após o acompanhamento de 5 anos, no "Beaver Dam Eye Study" observou uma associação discreta entre a ingestão de zinco e redução no risco de aparecimento de DMRI precoce (72) . Foi realizado outro estudo clínico, de caso-controle, durante dois anos, relacionando a suplementação de zinco e DMRI.…”

Vitaminas e antioxidantes na degeneração macular relacionada à idade

“…O "Beaver Dam Eye Study" demonstrou uma discreta associação entre a ingestão de zinco e uma diminuição do risco de aparecimento da DMRI precoce em cinco anos de acompanhamento (8) . Em outro trabalho prospectivo, a análise dos dados do "Nurses Health Study" e do "Health Professionals Follow-up Study" não mostrou qualquer efeito protetor para a DMRI, nos indiví-duos que ingeriram doses moderadas de zinco na sua dieta regular ou na forma de suplemento em 8 anos.…”