The study, led by Dr. Arjuna Ratnayaka, has shown how retinal pigment epithelial (RPE) cells in the eye become damaged due to poor nutrition including high fat and cholesterol-enriched food.
How an unhealthy diet could increase the likelihood of eye disease such as age-related macular degeneration (AMD) is still poorly understood, therefore scientists analysed how disease-causing pathways triggered by poor nutrition could impact RPE cells.
They found that healthy RPE cells had a considerable degree of flexibility to cope with changing conditions in the ageing eye but a high fat diet can disrupt this breakdown process in RPE cells.
Marco Pane, co-author of the study and R&D director at Biolab Research, said the discoveries contribute to a better understanding of the diet‐disease axis.
“These are strong and exciting findings because the probiotics intake managed to significantly and consistently improve several aspects of mood and sleep in a young and healthy population, which is among the most resilient population possible.
"They give positive expectations on how these results may translate to a clinical population. In fact this probiotics combination is now being tested in patients with major depression.”
AMD is an irreversible blinding disease caused by genetics and external factors such as smoking, high blood pressure or being overweight. It affects the central vision, which is used for reading and recognising faces and is a leading cause of sight loss in the UK – affecting more than 600,000 people.
Damage to RPE cells occur at the onset of AMD making them less equipped to support eye's photo receptors, the cells in the retina which respond to light. The death of photo receptors lead to permanent sight-loss.
The study determined how healthy RPE cells breakdown by-products generated by daily activities of photo receptors through the cells' waste disposal system.
Dr. Ratnayaka, lecturer in vision sciences at the university, said: "We also found that some lysosomes appeared to remain undamaged even in such stressed RPE, suggesting an altogether new way in which damaged cells could be rescued to prevent eventual sight-loss.
"As our results showed how the waste disposal system of the RPE becomes damaged by unhealthy diet-driven disease pathways, our next step is to find out whether this type of damage can be reversed through better nutrition and if stressed or damaged RPE cells can possibly be rescued.
"Potential new therapies developed along these lines could offer new treatments for some AMD patients."
Source: Molecular Nutrition & Food Research
Published online: DOI: 10.1002/mnfr.201800951
"Oxidative Stress and Dysfunctional Intracellular Traffic Linked to an Unhealthy Diet Results in Impaired Cargo Transport in the Retinal Pigment Epithelium"
Authors: Keeling. E., et al.