Lutein and Zeaxanthin Are Positively Associated with Visual–Spatial Functioning in Older Adults: An fMRI Study

Abstract

Lutein (L) and zeaxanthin (Z) are two xanthophyll carotenoids that have antioxidant and anti-inflammatory properties. Previous work has demonstrated their importance for eye health and preventing diseases such as age-related macular degeneration. An emerging literature base has also demonstrated the importance of L and Z in cognition, neural structure, and neural efficiency. The present study aimed to better understand the mechanisms by which L and Z relate to cognition, in particular, visual–spatial processing and decision-making in older adults. We hypothesized that markers of higher levels of L and Z would be associated with better neural efficiency during a visual–spatial processing task. L and Z were assessed via standard measurement of blood serum and retinal concentrations. Visual–spatial processing and decision-making were assessed via a judgment of line orientation task (JLO) completed during a functional magnetic resonance imaging (fMRI) scan. The results demonstrated that individuals with higher concentrations of L and Z showed a decreased blood-oxygen-level dependent (BOLD) signal during task performance (i.e., “neural efficiency”) in key areas associated with visual–spatial perception, processing, decision-making, and motor coordination, including the lateral occipital cortex, occipital pole, superior and middle temporal gyri, superior parietal lobule, superior and middle frontal gyri, and pre- and post-central gyri. To our knowledge, this is the first investigation of the relationship of L and Z to visual–spatial processing at a neural level using in vivo methodology. Our findings suggest that L and Z may impact brain health and cognition in older adults by enhancing neurobiological efficiency in a variety of regions that support visual perception and decision-making.

Visual Function and Macular Carotenoid Changes in Eyes with Retinal Drusen—An Open Label Randomized Controlled Trial to Compare a Micronized Lipid-Based Carotenoid Liquid Supplementation and AREDS-2 Formula

“…In other words, getting a more "redox homeostasis" could lead to a better visual function along with other neural processes [71]. This also has support with numerous studies showing the increased cognitive role of carotenoids [61][62][63][64][65][66][67][68].…”

“…Whereas the present study was a six-month supplementation trial, prior studies that showed a significant increase in measured MPOD in early macular degeneration needed a 12 month [25,45,48,57,59,60] or 24 month [57] intake of oral supplements to show a measurable increase in MPOD. MPOD is a useful biomarker and its levels correlate with retinal health [23][24][25]42,45,48,52,57,59,60] and various cognitive functions [61][62][63][64][65][66][67][68]. Further, the levels of carotenoids in brain, especially those found in the occipital lobe [69], correlate with macular carotenoid levels [70].…”

Macular Xanthophylls and Event‐Related Brain Potentials among Overweight Adults and Those with Obesity

“…Many of the recent findings surrounding lutein and neuroefficiency are rooted in studies utilizing the fMRI technique to assess efficiency using blood‐oxygen‐level‐dependent (BOLD) signaling. Colleagues Lindergh et al and Mewborn et al have demonstrated efficiency in the spatial dimension, noting increased efficiency in older adults in tasks of both verbal learning and visual‐spatial processing, respectively . Relying on the BOLD signal allows for unmatched spatial resolution, and provides invaluable information on the regions of the brain recruited to complete a task.…”

Lutein and Zeaxanthin Isomers Reduce Photoreceptor Degeneration in the Pde6brd10 Mouse Model of Retinitis Pigmentosa

“…L-Z, the two major xanthophylls, are the oxygenated forms of carotenoids [23] that are usually accumulated in the central retina of human eyes [24], with the protective effect in human and animal models of retinal degeneration [25–31]. However, the mechanism of L-Z in RP has not been clearly elucidated.…”