In contrast to findings in most Asian studies, total zinc intake is not associated with the presence of myopia in American children, according to an international team of researchers.

Their study evaluated 1,095 patients ranging in age from 12 to 19, of which 30% were myopic (≤-1.00D). In examining the relationship between total zinc intake and myopia, the researchers found the median total daily zinc intake was lower among myopes (10.8mg/d) than non-myopes (11.1mg/d); however, they note the difference was not statistically significant. They add that neither zinc nor copper intakes were significantly associated with myopia after adjusting for age, sex, body mass index, ethnicity, family income, recreational activity and daily energy intake. Spherical equivalent refractive error was not associated with total zinc intake in the myopic group either, after adjusting for confounding factors.

The study provides some much-needed perspective on the role of dietary factors in myopia progression, particularly in the United States.            

“It has been suggested in previous studies that lower zinc status is associated with myopia; however, this article shows no relationship between dietary zinc intake and myopia in US adolescents,” the authors note in the study.

Burke N, Butler JS, Flitcroft I, et al. Association of total zinc intake with myopia in U.S. children and adolescents. Optom Vis Sci. 2019;96(9):647-54.