Cognitive Function and Its Relationship with Macular Pigment Optical Density and Serum Concentrations of its Constituent Carotenoids

Abstract

Background: Macular pigment (MP) levels correlate with brain concentrations of lutein (L) and zeaxanthin (Z), and have also been shown to correlate with cognitive performance in the young and elderly.Objective: To investigate the relationship between MP, serum concentrations of L and Z, and cognitive function in subjects free of retinal disease with low MP (Group 1, n = 105) and in subjects with AMD (Group 2, n = 121).Methods: MP was measured using customized heterochromatic flicker photometry and dual-wavelength autofluorescence; cognitive function was assessed using a battery of validated cognition tests; serum L and Z concentrations were determined by HPLC.Results: Significant correlations were evident between MP and various measures of cognitive function in both groups (r = –0.273 to 0.261, p≤0.05, for all). Both serum L and Z concentrations correlated significantly (r = 0.187, p≤0.05 and r = 0.197, p≤0.05, respectively) with semantic (animal) fluency cognitive scores in Group 2 (the AMD study group), while serum L concentrations also correlated significantly with Verbal Recognition Memory learning slope scores in the AMD study group (r = 0.200, p = 0.031). Most of the correlations with MP, but not serum L or Z, remained significant after controlling for age, gender, diet, and education level.Conclusion: MP offers potential as a non-invasive clinical biomarker of cognitive health, and appears more successful in this role than serum concentrations of L or Z.

From neuro-pigments to neural efficiency: The relationship between retinal carotenoids and behavioral and neuroelectric indices of cognitive control in childhood

“…Mulder et al, 2014), that study based the analysis on plasma lutein and self-reported dietary intake of lutein while our study used MPOD, a retinal measure which may be more sensitive to cognitive measures than serum lutein. Kelly et al(2015) found that in adults, both macular pigment and serum lutein were associated with cognitive outcomes, but only the associations with macular pigment remained after controlling for relevant characteristics like sex, age, diet, and education level.…”

“…For example, lutein has been shown to correlate with many measures of cognition in healthy older adults (Vishwanathan, Iannaccone, et al 2014), adults with advanced macular degeneration (Kelly et al 2015), and those with mild cognitive impairment (Renzi et al 2014). Verbal fluency and memory have been shown to improve after supplementation of lutein and DHA in healthy older women (Johnson et al, 2008).…”

Serum and macular response to carotenoid-enriched egg supplementation in human subjects: the Egg Xanthophyll Intervention clinical Trial (EXIT)

“…Recent studies have also confirmed the presence of L and Z in the non-human primate brain (24) and the human brain (25)(26)(27) , and in concentrations that are proportional to retinal concentrations of these carotenoids. Interestingly, there is a growing body of evidence that these carotenoids may be important in maintaining optimal cognitive function (28)(29)(30)(31) .…”

Effects of Lutein and Astaxanthin Intake on the Improvement of Cognitive Functions among Healthy Adults: A Systematic Review of Randomized Controlled Trials

“…We excluded 13 relevant studies for using interventions other than carotenoids or its derivatives alone [52][53][54][55][56][57][58][59][60][61], not conducting cognitive assessment [62], and lack of a RCT [63].…”