PURPOSE: Zinc is found in high concentrations in the retina and is hypothesized to reduce the risk of age-related macular degeneration (AMD). Any long-term benefit associated with dietary zinc intake has not been evaluated. METHODS: We followed 66,572 women and 37,636 men who were > or = 50 years old and had no diagnosis of AMD or cancer. Zinc intake from food, multivitamins, and supplements was assessed with a semiquantitative food-frequency questionnaire at baseline (in 1984 for women and in 1986 for men) and repeated during follow-up (twice for women, once for men). RESULTS: During 10 years of follow-up for women and 8 years of follow-up for men, we confirmed 384 incident cases of AMD (195 cases of the early form and 189 cases of the late form) associated with a visual acuity loss of 20/30 or worse. After multivariate adjustment for potential risk factors, the pooled relative risk was 1.13 (95% confidence interval [CI], 0.82 to 1.57; p-value, test for trend, 0.74) among participants in the highest quintile of total zinc intake (energy-adjusted median; 25.5 mg/day for women and 40.1 mg/day for men) compared with those in the lowest quintile (energy-adjusted median; 8.5 mg/day for women and 9.9 mg/day for men). The relative risk for highest compared with lowest quintile was 1.04 (95% CI, 0.59 to 1.83; p-value, test for trend, 0.54) for zinc intake from food. Subjects who took zinc supplements had a pooled multivariate relative risk of 1.04 (95% CI, 0.75 to 1.45). CONCLUSIONS: In these two large prospective studies, moderate zinc intake, either in food or in supplements, was not associated with a reduced risk of AMD.
PURPOSE: Zinc is found in high concentrations in the retina and is hypothesized to reduce the risk of age-related macular degeneration (AMD). Any long-term benefit associated with dietary zinc intake has not been evaluated. METHODS: We followed 66,572 women and 37,636 men who were > or = 50 years old and had no diagnosis of AMD or cancer. Zinc intake from food, multivitamins, and supplements was assessed with a semiquantitative food-frequency questionnaire at baseline (in 1984 for women and in 1986 for men) and repeated during follow-up (twice for women, once for men). RESULTS: During 10 years of follow-up for women and 8 years of follow-up for men, we confirmed 384 incident cases of AMD (195 cases of the early form and 189 cases of the late form) associated with a visual acuity loss of 20/30 or worse. After multivariate adjustment for potential risk factors, the pooled relative risk was 1.13 (95% confidence interval [CI], 0.82 to 1.57; p-value, test for trend, 0.74) among participants in the highest quintile of total zinc intake (energy-adjusted median; 25.5 mg/day for women and 40.1 mg/day for men) compared with those in the lowest quintile (energy-adjusted median; 8.5 mg/day for women and 9.9 mg/day for men). The relative risk for highest compared with lowest quintile was 1.04 (95% CI, 0.59 to 1.83; p-value, test for trend, 0.54) for zinc intake from food. Subjects who took zinc supplements had a pooled multivariate relative risk of 1.04 (95% CI, 0.75 to 1.45). CONCLUSIONS: In these two large prospective studies, moderate zinc intake, either in food or in supplements, was not associated with a reduced risk of AMD.
Authors: Redmer van Leeuwen; Caroline C W Klaver; Johannes R Vingerling; Albert Hofman; Paulus T V M de Jong Journal: Eur J Epidemiol Date: 2003 Impact factor: 8.082
Authors: Xuehong Zhang; Edward L Giovannucci; Stephanie A Smith-Warner; Kana Wu; Charles S Fuchs; Michael Pollak; Walter C Willett; Jing Ma Journal: Cancer Causes Control Date: 2011-09-11 Impact factor: 2.506
Authors: Ashwin N Ananthakrishnan; Hamed Khalili; Mingyang Song; Leslie M Higuchi; James M Richter; Andrew T Chan Journal: Int J Epidemiol Date: 2015-12 Impact factor: 7.196