Macular Carotenoid Supplementation Protects Against Damaging Blue Light

by | Jul 29, 2019 | 2017, Carotenoids, Eye Health, Lutein, Zeaxanthin

Written by Joyce Smith, BS. Increased macular pigment optical density (MPOD) improved visual performance and other symptoms of excessive “screen time” exposure.

computerThe average American spends over 10 hours per day looking at smartphones, tablets or computer screens 1. Undesirable effects on sleep quality and alertness while awake and on physical health include neck and eye strain, eye fatigue, headache 2 and cognitive performance such as poor inhibitory control 3. These complaints associated with excessive computer and digital devices have been collectively termed “computer vision syndrome”. Long-term cumulative effects of the blue light emitted from prolonged use of these devises may in time damage the retina and contribute to the development of age-related macular degeneration.

Diet-derived blue light absorbing pigments, found in the dietary carotenoids lutein (L), zeaxanthin (Z), and mesozeaxanthin (MZ), are known collectively as macular pigment (MP), and are abundant in green leafy vegetables 4. MPs are deposited in the macular retina 5 where they function as potent antioxidants and anti- inflammatories, protecting the retina from age-related macular degeneration (AMD) 6. These pigments also function as blue light filters that may benefit individuals who have excessive “screen time” (ST) exposure and suffer from reduced visual performance. Past studies have shown MP to significantly improve several aspects of visual performance that may be related to excessive screen time exposure.  These include contrast sensitivity (CS) 7, temporal vision 8, disability glare (DG), critical flicker fusion (CCF), and photo stress recovery. A low macular pigment optical density (MPOD) is a key risk factor for AMD while a high macular pigment optical density not only reduces one’s risk for AMD but also helps to improve visual performance.

The present 6-month randomized, double-blind, placebo-controlled trial was designed to 9 to  investigate the baseline relationships between MPOD, visual performance measures, sleep quality, and physical indicators of excessive screen time (ST) in young, healthy adults; and to determine effects of a 6-month MC supplementation on these same outcomes. It involved 48 healthy young adults with screen time exposure of at least 6 hours daily who supplemented with 24 mg of L, Z and MZ  (n=35) or  a placebo  (n=13 ). Subjects were evaluated at baseline, 3- months and 6- months for Macular Pigment Optical Density (MPOD) and markers of visual performance.

Compared to placebo, six months of supplementation with 24 mg of MCs led to significant improvements of approximately 30% in  each of the visual performance measures: decreased glare (p=0.021), critical flicker fusion (p<0.001), increased contrast sensitivity (p=0.002) and improved photostress recovery (p=0.011)]. Included also was a significant increase in MPOD (p=0.015). Along with these visual improvements, subjects had significantly improved sleep quality (p=0.01), and significantly fewer headaches (0.029), eyestrain (0.046), and eye fatigue (p=0.016).

This study offers a benign, nutrition-based therapy for reducing the incidence of many undesirable outcomes associated with excessive ST.  Of particular interest would be investigating the benefits of nutritional intervention in children under 10 years of age to offset potential visual, physical, or even behavioral outcomes given the dramatic rise in use of handheld devices and computers by this age group.

Source: Stringham, James, Nicole Stringham, and Kevin 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. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

Click here to read the full text study. 

Posted July 29, 2019.

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.

References:

  1. Nielsen. The Nielsen Total Audience Report: Q1, 2016. https://www.nielsen.com/us/en/insights/report/2016/the-total-audience-report-q1-2016/. Accessed April 10, 2017.
  2. Toomingas A, Hagberg M, Heiden M, Richter H, Westergren K-E, Tornqvist EW. Risk factors, incidence and persistence of symptoms from the eyes among professional computer users. Work. 2014;47(3):291-301.
  3. Chen J, Liang Y, Mai C, Zhong X, Qu C. General deficit in inhibitory control of excessive smartphone users: Evidence from an event-related potential study. Frontiers in psychology. 2016;7:511.
  4. Humphries JM, Khachik F. Distribution of lutein, zeaxanthin, and related geometrical isomers in fruit, vegetables, wheat, and pasta products. Journal of Agricultural and Food Chemistry. 2003;51(5):1322-1327.
  5. Bone RA, LANDRUM JT, FRIEDES LM, et al. Distribution of lutein and zeaxanthin stereoisomers in the human retina. Experimental eye research. 1997;64(2):211-218.
  6. Richer S, Stiles W, Statkute L, et al. Double-masked, placebo-controlled, randomized trial of lutein and antioxidant supplementation in the intervention of atrophic age-related macular degeneration: the Veterans LAST study (Lutein Antioxidant Supplementation Trial). Optometry-Journal of the American Optometric Association. 2004;75(4):216-229.
  7. Stringham JM, O’Brien KJ, Stringham NT. Contrast sensitivity and lateral inhibition are enhanced with macular carotenoid supplementation. Investigative ophthalmology & visual science. 2017;58(4):2291-2295.
  8. Renzi LM, Hammond Jr BR. The relation between the macular carotenoids, lutein and zeaxanthin, and temporal vision. Ophthalmic and Physiological Optics. 2010;30(4):351-357.
  9. Stringham JM, Stringham NT, O’Brien KJ. Macular Carotenoid Supplementation Improves Visual Performance, Sleep Quality, and Adverse Physical Symptoms in Those with High Screen Time Exposure. Foods. 2017;6(7):47.