Eye health science and supplements: The long view
“Of all five senses,” observes Karen Hecht, PhD, scientific affairs manager, AstaReal USA Inc. (Burlington, NJ), “vision is the prime one most of us rely on for information.” A Research!America poll even found that 88% of respondents consider vision to be vital, with 47% agreeing that losing sight would have the most impact on their lives, precipitating lost independence and a dramatic disruption of daily activities.1
So it’s surprising—and a little ironic—that vision is also the sense that’s easiest to take for granted, until it starts to wane. And with screen time, blue light, environmental assaults, and the process of aging all exacting a toll on our eyesight, that time of waning is arriving sooner than before.
But it doesn’t have to, for researchers are finding that dietary supplementation can go a long way toward shoring up ocular health and protecting eyes against the battery of threats they face. The science—and the possibilities for nutritional interventions it suggests—are worth looking at.
Eyes in Danger
Given vision’s primacy in our lives, it’s remarkable how sensitive and vulnerable the organs responsible for it are. But they’re hardly defenseless.
As Brian Appell, marketing manager, OmniActive Health Technologies (Morristown, NJ), explains, “We’re constantly bombarded by different wavelengths of light, including UV and high-energy blue light. The good news is that eyes are incredibly effective at blocking UV radiation from the sun, only allowing about 1% to reach the retina, which is at the very front of the eye.”
The bad news is that eyes are less adept at filtering the high-energy blue light emitted not only by the sun, but from digital device screens and even energy-efficient lighting. “In fact,” Appell says, “almost all blue light reaches the retina and travels all the way to the macula, which is located at the very back of the eye.”
Modern Problems
High-energy blue light is a concern on a number of counts. For one, it generates considerable oxidative stress within the eye. It also reduces contrast, which keeps eyes in a continual state of having to re-accommodate focus. This overworks the ciliary muscles that help our eyes adjust to viewing at different distances, and it produces the eye strain and fatigue that go by the very 21st-century name of computer vision syndrome, or CVS.
While this news won’t likely convince us to abandon our digital devices, it may further complicate our love/hate relationship with them. For Hecht notes that the average American spends 7.5 hours daily focusing on screens at an average distance of 14 inches away, bathing their eyes in the blue light and ciliary stress that cause 65% of American computer users and approximately 60 million people worldwide to suffer from eye strain.
Even kids get hit. While 66% of U.S. adults cop to spending too much time on digital devices, research by Kemin (Des Moines) reveals that fully 69%of parents of 6- to 12-year-olds report not only that their child uses digital devices, but that their use won’t likely diminish, as it’s part of both leisure and school routines.2
Macula Matters
That means exposure to blue light starts early and worsens with time. But the eye’s macula—a pigmented region specialized for high-acuity vision and a victim of blue light—may contain the secret to countering the high-energy wavelength’s menace.
That’s because it’s where the three main macular carotenoids congregate: lutein in the peripheral macula, RR-zeaxanthin in the mid-peripheral macula, and RS-zeaxanthin in the center. “The macular carotenoids are imperative to healthy vision for a lifetime,” Appell explains, “and as more science comes out, it seems their ‘magic’ comes from the combination of all three.”
However, the body doesn’t produce lutein and the zeaxanthin isomers de novo, and we know dietary intake to be low.3 As a result, “The average individual isn’t getting enough from dietary sources to increase their macular pigment optical density—or MPOD—to a level that provides significant protection from blue light,” says Ceci Snyder, MS, RD, global vision product manager, human nutrition and health, Kemin (Des Moines).
The Case for Supplementation
That’s where supplementation comes in. “Solid scientific evidence supports the benefits of supplementation with lutein and zeaxanthin for eye health,” Snyder continues, pointing to the largest study to examine its effects on age-related macular degeneration (AMD) thus far: the Age-Related Eye Disease Study 2 (AREDS2), conducted by the U.S. National Eye Institute.
Appell agrees, adding that while no defined requirement for the major dietary carotenoids yet exists, the data suffices to consider lutein and zeaxanthin’s isomers “conditionally essential,” he says. “Their importance to eye health should not be understated, especially considering the growing prevalence of AMD, one of the leading causes of vision impairment globally.”
Beyond Baseline
The evidence supporting macular carotenoids’ protective effects is undeniable, and imperative, given the threats to basic ocular health we face. But, Appell notes, emerging research is affirming how these nutrients not only help us see, period, but help us see better.
Endpoints like contrast sensitivity, photo-stress recovery, and glare performance are all quantifiable measures of how well we see under different circumstances, Appell says, and as such, they offer “a huge opportunity in the eye-health market.”
Consider that “how we react within our environments starts with how rapidly visual information travels from our eyes to our brain—visual processing speed,” Appell says. “Improving visual processing speed through supplementation provides new opportunities in categories like sports nutrition, where reaction time is key.”
So a time will come when the eye-health category will be about more than just prevention; it’ll offer optimization, “providing ‘immediate’ benefits that are important and relevant to consumers,” Appell says. “That, in turn, requires new science to elucidate and support these benefits.”
Check out the following pages to see what some of that science is revealing.
References
1. Research!America press release. “New Public Opinion Poll Reveals a Significant Number of Americans Rate Losing Eyesight as Having Greatest Impact on Their Lives Compared to Other Conditions.” September 18, 2014. Accessed at: http://eyeresearch.org/pdf/Poll_press_release.pdf
2. Kemin/DSM Consumer Research, 2018.
3. Johnson et al. Journal of the American Dietetic Association, vol. 110, no. 9 (2010):1357-62