Macular Pigment, Cognition, and Visual Function in Younger Healthy Adults in Ghana

Article type: Research Article

Authors: Akuffo, Kwadwo Owusu^{a; *} | Wooten, Billy R.^b | Ofori-Asare, Wendy^a | Osei Duah Junior, Isaiah^{a; c} | Kumah, David Ben^a | Awuni, Moses^a | Obiri-Yeboah, Stephannie Rhoda^a | Horthman, Stacy Ewurama^a | Addo, Emmanuel Kofi^{a; d; e} | Acquah, Eldrick Adu^a | Boateng, Bridget Senya^f | Johnson, Elizabeth J.^g

Affiliations: [a] Department of Optometry and Visual Science, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana | [b] Department of Psychology, Brown University, Providence, RI, USA | [c] Purdue University Biological Sciences, West Lafayette, IN, USA | [d] Department of Ophthalmology and Visual Sciences, Moran Eye Centre, University of Utah, Salt Lake City, UT, USA | [e] Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA | [f] Chengde Medical University, Shuangqio District, Chengde Hebei, China | [g] Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA

Correspondence: [*] Correspondence to: Kwadwo Owusu Akuffo, Department of Optometry and Visual Science, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. Tel.: +233 507315144/501580605; E-mail: koakuffo@gmail.com., E-mail: akuffokwadwoowusu@knust.edu.gh.

Abstract: Background:Macular pigment optical density (MPOD) remains an indispensable biomarker to measure fruit and vegetable intake, with a biologically plausible correlation to vision and cognition. However, evidence in the sub-Saharan regions, including Ghana, is lacking. Objective:This study explored dietary carotenoid intake on MPOD and its influence on cognitive and visual function in a healthy Ghanaian sample. Methods:The MPOD of 301 healthy subjects (aged 21.1±1.9 years) was evaluated using the customized Macular DensitometerTM. A battery of cognitive tests and standard vision assessments were employed to assess cognition and visual function, respectively. Dietary lutein and zeaxanthin (L and Z) were estimated based on a twenty-four-hour repeated dietary recall. Results:The mean MPOD at 0.5° and 1.0° eccentricities were 0.37±0.16 and 0.34±0.15 optical density units, respectively. Dietary intake of L (4.06±10.54 mg/day) was considerably higher than Z (0.33±2.25 mg/day), with cumulative L+Z estimated at 4.39±11.58 mg/day. MPOD was not significantly influenced by demographic, dietary, and visual measures (p≥0.05). However, after statistical adjustment, we found a small but statistically significant positive relationship between F-A-S phonemic verbal fluency (Unstandardized co-efficient (β) = 0.002, p = 0.016) and the never consumed alcohol category (β= 0.062, p = 0.02) with MPOD. Conclusion:The findings in this population showed significant positive relationships between measures of cognition and no alcohol intake, with MPOD. These findings necessitate dietary education to augment carotenoid intake and limit alcohol intake for better cognitive functioning.

Keywords: Alzheimer’s disease, cognition, heterochromatic flicker photometry, lutein, macular pigment optical density, vision, zeaxanthin

DOI: 10.3233/JAD-230233

Journal: Journal of Alzheimer's Disease, vol. 94, no. 1, pp. 405-413, 2023