Macular Carotenoids Improve Visual Performance and Physical Symptoms in Those With High Screen Exposure

by | Dec 5, 2017 | 2017, Eye Health, Lutein, Zeaxanthin

Written by Joyce Smith, BS. A 6-month supplementation with lutein, zeaxanthin, and mesozeaxanthin significantly improved macular pigment optical density, temporal vision as well as sleep quality, contrast sensitivity, disability glare, photo stress recovery, headache frequency, and eye strain and fatigue.

headacheAbundantly present in green leafy vegetables 1, the dietary carotenoids lutein, zeaxanthin and mesozeaxanthin exist in rich concentrations in the macular retina 2. These yellow-orange pigments, collectively known as macular pigment are powerful antioxidants that protect the retina from age-related macular degeneration 3, and function as a blue light filter to protect against photo-oxidation and improve aspects of visual performance glare, visual discomfort 4, disability glare 5, and photostress recovery 6.

Studies have shown that people who spend up to nine hours per day on electronic light-emitting devices such as smart phones, tablets and computers have reduced sleep quality and daytime alertness, as well as increased neck and eye strain, eye fatigue, and headaches 7. These detrimental effects have collectively been termed Computer Vision Syndrome.8 Researchers striving to determine the negative effects of Computer Vision Syndrome, investigated whether the optical density of macular pigment (MPOD) might mitigate the negative effects of excessive screen time and whether those of us with low amounts or no macular carotinoids 9 are more vulnerable to its deleterious effects. Thus the two primary study goals were to determine a baseline relationship between MPOD, visual performance measures, sleep quality and symptoms of excessive screen time in young healthy adults and to assess how a 6-month supplementation with macular carotenoids would affect the outcomes associated with it.

This randomized double-blind, placebo-controlled trial consisted of 25 female/ 23 male (aged18-25 years), healthy non-smokers with a body mass index (BMI) < 27, who received either a daily capsule of 24 mg daily of lutein, zinc, and mezozeaxanthin (ratio of 83:10: 7) (n= 35) or a placebo (n=13). All subjects spent at least 6 hours daily viewing screens at a distance of three feet or less and, in addition, were required to complete a questionnaire that included items specific to smartphones, tablets, computers and television viewing. The following measures of all visual and physical parameters were taken at baseline and at 3 and 6 months: macular carotenoid supplementation, measurements of macular pigment optical density and temporal vision, physical indicators of excessive screen time, sleep quality, contrast sensitivity testing, disability glare, photostress recovery, and statistical analysis.

Results were as follows: After 3 months of supplementation, temporal vision (p=0.023) and overall sleep quality (p=0.025) changed significantly compared to placebo. After 6 months of supplementation MPOD (p = 0.015), temporal vision (p < 0.001), sleep quality (p = 0.01), contrast sensitivity (p = 0.002), disability glare (p = 0.021), photostress recovery (p = 0.011), headache frequency (p = 0.029), eye strain (p = 0.046), and eye fatigue (p = 0.016) improved significantly. Blurry vision, neck strain, consumption of foods containing L and Z, and estimates of screen time did not change appreciably throughout the study period in either the placebo or treatment groups.

The results of this study offer a benign, nutrition-based therapy for reducing the incidence of many undesirable outcomes associated with excessive screen time. These results also motivate the need for more and larger studies involving different age groups; in particular, the 40-45 year age group where presbyopia may exacerbate issues associated with excessive screen time such as excessive squinting due to diminished lens accommodative ability. Children represent another area of concern in that under 10 years of age they have exceptionally clear crystalline lenses 10,11, and may not have had sufficient time or adequate diet to accumulate appreciable MP. The clarity of the lens (which normally yellows slightly with age) allows more high-energy blue light to reach the retina, where insufficient MP may compromise the ability of the retina to deal with oxidative stress. Given the recent dramatic rise in the use of handheld devices and computers by this age group 12, additional research is necessary to evaluate whether nutritional intervention could help with potential visual, physical, or perhaps behavioral outcomes of this vulnerable age group.

Source: String ham, James M., Nicole T. String ham, and Kevin J. O’Brien. “Macular Carotenoid Supplementation Improves Visual Performance, Sleep Quality, and Adverse Physical Symptoms in Those with High Screen Time Exposure.” Foods 6, no. 7 (2017): 47.

© 2017 by the authors. Licensee MDPI, Basel, Switzerland. Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

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Posted December 5, 2017.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

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