Dietary composition plays a crucial role in the development of myopia through the inflammatory pathway: a Mendelian randomization study

Abstract

Background: Myopia is a major cause of global visual impairment, posing significant public health concerns, impacting daily lives, and leading to severe complications. Dietary factors may influence myopia development, while inflammation plays a role in various diseases and may contribute to myopia occurrence. This study aimed to investigate the impact of carbohydrate, protein, fat, and sugar intake on myopia using MR analysis. Additionally, we explored inflammation's potential role as a mediator. By elucidating partial mechanisms of myopia and providing innovative prevention strategies, we aim to alleviate the global burden of myopia on public health. Methods: We performed mediation MR analyses using large-scale GWAS data from the SSGAC database for four dietary components (carbohydrates, fats, proteins, sugars) of European ancestry, as well as inflammation-related factors (adiponectin, C-reactive protein, tumor necrosis factors, interleukins, nuclear factor-kappa B subunit gamma inhibitor) of European ancestry from the IEU database, and large-scale GWAS data for myopia of European ancestry from the IEU database. Additionally, we conducted bidirectional two-sample MR analyses among selected inflammation-related factors to explore their interrelationships. The inverse-variance weighted method was used as the primary analysis approach, supplemented by comprehensive sensitivity analyses. Results: Inverse-variance weighted models showed positive associations between protein and fat intake and myopia risk. Carbohydrate and sugar intake had no significant association with myopia risk. Adiponectin was negatively correlated, while C-reactive protein and interleukin-18 were positively associated with myopia risk. No significant correlations were found for other inflammation-related factors. Protein intake correlated positively with tumor necrosis factor-alpha and negatively with tumor necrosis factor-beta. Fat intake correlated positively with adiponectin and tumor necrosis factor-alpha, and negatively with interleukin-27. No significant associations were observed for protein and fat intake with other inflammation-related factors. No significant associations were found between pairs of inflammation-related factors. Conclusions: Our findings suggest that a high-fat and high-protein diet may increase myopia risk. Inflammation likely contributes to myopia, but underlying mechanisms are unclear. Excessive protein and fat intake may worsen inflammation. These findings emphasize the importance of dietary modifications and inflammation control for myopia prevention. Further research is needed to understand specific mechanisms and develop targeted dietary interventions.

Myopia, Sodium Chloride, and Vitreous Fluid Imbalance: A Nutritional Epidemiology Perspective

“…In particular, dietary salt restriction was ignored for decades as an effective and inexpensive treatment to reduce hypertension and to lower the effects of related ocular pathologies [13]. Moreover, as of 2023, "there are numerous conflicting findings, and no definitive consensus has been reached on the impact of diet on the occurrence and progression of myopia" [14]. For example, Chua et al found that dietary assessments of protein, fat, carbohydrate, and energy in Singaporean children were not associated with the development of myopia at three years of age [15] and nine years of age [16], yet dietary sodium is not mentioned in either study.…”