Linkage between a plant-based diet and age-related eye diseases: a systematic review and meta-analysis

Abstract Context An increased risk of age-related eye disease has been observed in individuals lacking a balanced diet. Following a plant-based diet may result in nutritional insufficiencies and negatively affect health if an effort is not made to ensure the consumption of fortified foods or specific supplements. Objective The purpose of this article is to characterize the relationship between plant-based diets and age-related ocular outcomes among adults. Data Sources A comprehensive literature review was performed using the MEDLINE, Embase, Cochrane, and PubMed databases up until December 19, 2021. Study Selection Studies that focused on observed visual changes due to a reduced intake of animal products and that included a minimum of 50 eyes were eligible for inclusion. Data Extraction Two levels of screening, quality assessment, and data extraction were conducted by 2 reviewers independently. The 21 studies identified from 814 unique studies progressed to data extraction and 15 were included in the quantitative analysis using STATA 15.0 fixed-effect and random-effect models computed on the basis of heterogeneity. Results The 15 (n = 51 695 participants) assessed the impact of fish consumption, 8 studies (n = 28 753 participants) analyzed the effect of red meat intake, and 3 studies (n = 7723 participants) assessed the impact of omission of skim milk, poultry, and non-meat animal products and the presence of disease incidence as indicated by age-related macular degeneration or cataract development. Meta-analysis indicated regular consumption of fish (odds ratio [OR], 0.70; 95%CI, 0.62–0.79) and skim milk, poultry, and non-meat animal products (OR, 0.70; 95%CI, 0.61–0.79) reduced the risk of age-related eye disease development among adults. Consumption of red meat (OR, 1.41; 95%CI, 1.07–1.86) may increase the risk of age-related eye disease development. Conclusion A pescatarian diet is associated with the most favorable visual outcomes among adults, whereas consumption of red meat negatively affects ocular health. Results suggest a need for more initiatives promoting a healthy and balanced diet. Systematic Review Registration PROSPERO registration no. CRD42021269925