Macular pigment optical density is positively associated with academic performance among preadolescent children

Abstract

Objective: Macular pigment optical density (MPOD) – a non-invasive indicator of retinal xanthophylls and correlate of brain lutein – has been associated with superior cognitive function among adult populations. Given that lutein accumulation in the brain occurs in early life, it is possible that the cognitive implications of greater MPOD may be evident in childhood.

Methods: Participants aged 8–9 years (n = 56) completed MPOD measurements via heterochromatic flicker photometry. Academic performance was assessed using the Kaufman Test of Academic and Educational Achievement II (KTEA). Habitual dietary intake of L and Z was measured among a subsample of participants (n = 35) using averaged 3-day food records. Stepwise hierarchical regression models were developed to determine the relationship between MPOD and academic achievement tests, following the adjustment of key covariates including sex, aerobic fitness, body composition, and intelligence quotient (IQ).

Results: The regression analyses revealed that MPOD improved the model, beyond the covariates, for overall academic achievement (ΔR² = 0.10, P < 0.01), mathematics (ΔR² = 0.07, P = 0.02), and written language composite standard scores (ΔR² = 0.15, P < 0.01).

Discussion: This is the first study to demonstrate that retinal L and Z, measured as MPOD, is positively related to academic achievement in children, even after accounting for the robust effects of IQ and other demographic factors. These findings extend the positive associations observed between MPOD and cognitive abilities to a pediatric population.

Trail registration: The Fitness Improves Thinking in Kids 2 (FITKids2) trial was registered at www.clinicaltrials.gov as NCT01619826.

Keywords:

• Preadolescent children
• Lutein
• Zeaxanthin
• Academic performance
• Macular pigment optical density

Acknowledgements

We thank Bonnie Hemrick and Jeanine Bensken for their assistance in recruiting and scheduling participants.

Availability of data and material

The datasets generated during and/or analyzed during the current study are not publicly available, but are available from the corresponding author on reasonable request.

Disclaimer statements

Contributors The authors’ responsibilities were as follows – SMB, NAK, NJC, AFK, BRH, LR-H, and CHH: designed the research; SMB: conducted the research; SMB: analyzed the data; SMB wrote the initial draft of the manuscript and had primary responsibility for the final content. All authors read and approved the final manuscript.

Funding This work was supported by NIH under Grant HD069381 and Abbott Nutrition via a Center for Nutrition, Learning, and Memory (CNLM) grant to the University of Illinois.

Conflicts of interest Christopher Moulton was employed by Abbott Nutrition, and Sasha M Barnett was an intern at Abbott after the work for the manuscript was completed. No other authors have any conflicts of interest.

Ethics approval All participants provided written assent and their legal guardians provided written informed consent in accordance with the ethical standards and regulations of the Institutional Review Board (IRB) of the University of Illinois at Urbana-Champaign (Institutional Review Board number 12321).

ORCID

Sasha M. Barnett http://orcid.org/0000-0002-9945-9131

Naiman A. Khan http://orcid.org/0000-0002-6135-9389

Christopher Moulton http://orcid.org/0000-0002-5109-1489

Neal J. Cohen http://orcid.org/0000-0001-5556-0417

Arthur F. Kramer http://orcid.org/0000-0002-1991-5046

Billy R. Hammond Jr http://orcid.org/0000-0002-5762-0206

Lisa Renzi-Hammond http://orcid.org/0000-0003-4334-8202

Charles H. Hillman http://orcid.org/0000-0002-3722-5612