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High Screen Time & Macular Carotenoids

Friday, July 07, 2017

According to a study published in the July 2017 journal Foods, prior to the advent of artificial lighting, the sun was the primary source of light. However, when the sun sets today, we are hard pressed to find darkness—illumination from ​LEDs, ​incandescent and fluorescent lights provides indoor and outdoor illumination.

The effects of exposure to this seemingly unnatural technological adaption are starting to become evident, with an ever-growing number of studies indicating undesirable associations between exposure to artificial light at night and the related reduced-sleep, quality-diminished alertness during the day.


A fairly recent concern is the excessive near-field exposure to handheld and other electronic light-emitting devices. Estimates from large population surveys in developed countries indicate that 35 percent of people born between the years of 1965 and 1996 spent at least nine hours a day on blue light digital devices, such as smartphones, tablets or computers, with Americans spending at least 10 hours a day on digital devices.

The collective medical complaint associated with this excessive use of computers and other digital devices is termed Computer Vision Syndrome.  The long-term damage from this syndrome includes artificial light associated with oxidative stress linked to eye strain, eye fatigue; neck strain and sleep quality.

Enter macular carotenoids

A new double-masked, randomized, placebo-controlled supplementation six-month study was conducted at the University of Georgia by the esteemed carotenoid researchers Drs. James Stringham, Nicole Stringham and Kevin O'Brien on 48 ocular-pathology-free subjects with a body mass index (BMI)​ ofmore than 27—higher than the norm, but well below obese. 

The concern with BMI involved good general health, but also the possibility that supplemented macular carotenoids may be deposited in adipose tissue, reducing the amount deposited in the retina, and putting this population at greater risk of reduced visual health.

The study investigators measured before and after macular pigment optical density, contrast sensitivity, disability glare and photostress recovery. Physical indicators of excessive screen time and sleep quality were assessed, as was visual performance measures, versus placebo.

The subjects were advised to continue their normal diets and they were evaluated for diet change during each weekly compliance visit. They were randomly assigned to either safflower oil placebo or 24 mg of lutein, zeaxanthin and meso-zeaxanthin supplement in a ratio of 83 percent, 10 percent, and 7 percent, respectively.

Study conclusion

In subjects with a BMI of 27, daily supplementation with 24 mg of macular carotenoids significantly improved macular pigment optical density, overall sleep quality, eye strain, eye fatigue, and all visual performance measures, versus placebo. Frequency of blurry vision and neck strain did not change.

Ellen Troyer with Spencer Thornton, MD, David Amess and the Biosyntrx staff


Systemic reviews and meta-analysis are now suggesting that the macular carotenoids, lutein, zeaxanthin and meso-zeaxanthin, may play an important role in eye, brain and skin health across the entire life span. Blurry vision is also frequently related to dryness and tear film instability.

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