Is There Any Association between Nutrition and Myopia? A Systematic Review

SIGNIFICANCE This systematic review highlights the possible role of nutrition in myopia based on qualitative analysis of vast and diverse literature that investigated this association. PURPOSE We systematically reviewed the outcomes of the studies that previously investigated the association between nutrition and myopia. METHODS EMBASE, MEDLINE, and PubMed were searched by two independent authors to identify cross-sectional, cohort, retrospective, or interventional studies that assessed the association of nutrition with myopia from inception to the year 2021. Furthermore, the reference list of the included articles was screened. The data from the included studies were extracted, and qualitative analysis was performed. Quality assessment for noninterventional studies and interventional trials was performed using the Newcastle-Ottawa Scale and Cochrane RoB 2, respectively. RESULTS Twenty-seven articles were included in the review. Most of the nutrients and dietary elements investigated in noninterventional studies showed inconsistencies in their association with myopia, with the majority indicating no association. Nine studies showed a significant association of diverse nutrients and dietary elements with either an increase (odds ratio, 1.07) or a decrease (odds ratio, 0.5 to 0.96) in the risk of myopia development. However, a majority of these studies have minimal odds ratios with wider or overlapping confidence intervals, implicating weaker associations. All three nutrients and dietary elements assessed in the interventional trial had implications for myopia control, with two trials indicating a clinically minimal effect. CONCLUSIONS This review implies that there is some evidence to indicate a potential influence of specific nutrients and dietary elements in myopia development, which are supported by several theories. However, given the vast, diverse, and complex nature of nutrition, more systematic investigation is warranted to comprehend the extent to which these specific nutrients and dietary elements are associated with myopia through longitudinal studies by subduing the limitations in the existing literature.