Introduction
This study marked an important step in exploring the potential role of macular carotenoids, nutrients we’ve long studied in the eye, in brain health. At the same time as our research in Ireland, a complementary study in the US analysed post-mortem donated brains and confirmed for the first time that macular pigment levels measured in living eyes correlate strongly with carotenoid levels in the brain.
Why was the research undertaken?
Given this new understanding, we wanted to see if macular pigment scores could serve as a non-invasive indication (marker) of brain carotenoid status and cognitive function in a large, representative population of older adults. This led to a collaboration between my centre, the Nutrition Research Centre Ireland, and the Irish Longitudinal Study on Ageing (TILDA) based in Trinity College, Dublin.
How was the study conducted?
The research team measured macular pigment density, both in the eye and blood, in a large random sample of over 5,000 adults aged 50 and older from across Ireland. We then analysed these measures in relation to detailed cognitive performance tests, covering reaction time, memory and other cognitive abilities.
What were the results?
We discovered a strong positive correlation: people with higher macular pigment levels consistently performed better across multiple measures of cognitive function. This powerful observational study was one of the first to show such a large-scale link between these carotenoids and brain health in living adults.
What is the societal benefit?
This work laid the foundation for exploring carotenoids as a potential protective factor for cognitive decline and dementia. It underscored the importance of developing novel, non-invasive biomarkers for identifying individuals at risk and highlighted the potential for nutritional strategies to support brain health. Following this, we expanded our research into Alzheimer’s disease directly.
