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

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.