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

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 Densitometer (TM). 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 degrees and 1.0 degrees eccentricities were 0.37 +/- 0.16 and 0.34 +/- 0.15 optical density, 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 (beta) = 0.002, p = 0.016) and the never consumed alcohol category (beta = 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.

Automated summary

This study aimed to investigate the influence of dietary carotenoid intake on visual and cognitive function. The results showed a positive correlation between macular pigment optical density (MPOD) and phonemic verbal fluency and alcohol intake. Therefore, dietary education to increase carotenoid intake and limit alcohol consumption is necessary for better cognitive functioning.