How Can Healthful Plant-Based Diets Support Retinal Health? Findings from a Large Cohort Study

This article explores the relationship between healthful plant-based diets and retinal health, drawing on findings from a large-scale population-based study using data from the UK Biobank.

Key Findings:

A study utilizing data from the UK Biobank (13,993 participants with complete optical coherence tomography (OCT) measurements and dietary assessments) investigated the associations between four diet assessment scores and retinal sublayer thickness. The dietary patterns analyzed were:

• Alternate Mediterranean Diet (AMED)
• Anti-Empirical Dietary Inflammatory Index (AEDII)
• Alternate Healthy Eating Index-2010 (AHEI-2010)
• Healthful Plant-Based Diet Index (HPDI)

Retinal sublayers measured included:

• Macular retinal nerve fiber layer (mRNFL)
• Macular ganglion cell-inner plexiform layer (mGCIPL)
• Macular ganglion cell complex (mGCC)
• Retinal pigment epithelium (mRPE)
• Outer nuclear layer of the central subfield (ONL)
• Photoreceptor inner segment of the central subfield (IS)
• Total macular thickness

Significant Positive Associations: Higher Healthful Plant-Based Diet Index (HPDI) scores showed significant positive associations with:

• Increased central retinal macular thickness (β = 0.106, p = 0.001)
• mGCIPL thickness (β = 0.017, p = 0.033)
• ONL thickness (β = 0.044, p = 0.003)
• IS thickness (β = 0.003, p = 0.005)
• mGCC thickness (β = 0.027, p = 0.025)

Other Findings:

• The AMED, AEDII, and AHEI-2010 scores did not show consistent associations with retinal sublayer thickness, except for ONL and IS.
• Mediation analysis suggested cholesterol acted as a suppressor variable, partially mediating the relationship between HPDI and retinal sublayer thickness.
• Associations between HPDI and retinal sublayer thickness were more pronounced in younger individuals and females.

Conclusion:

The study suggests that a healthful plant-based diet may offer neuroprotective benefits, especially for retinal ganglion cell health. This large cohort study highlights the potential role of diet in mitigating early neurodegenerative changes detectable through non-invasive retinal imaging. Further longitudinal research is needed to confirm causal relationships and clarify the underlying mechanisms.