Relying upon Diet to Enhance Your Visual Experiences!
If you live in North America, you can expect to see fireworks this weekend as both Canadians and Americans will be celebrating. Several years ago, my wife and I were flying across the US on July 4th and we could see fireworks below our plane as it descended into Newark airport. We were awed by the contrasting explosions of bright colors against the darkening skies below us. Our visual acuity was aided by xanthophyll carotenoids concentrated in the macula of the retina.
With over 600 carotenoids found in nature, 50-60 are regularly consumed in our diet and only two dietary forms, lutein and zeaxanthin, are found in the blood. These two carotenoids are concentrated within the macula of the eye. Retinal cells convert some lutein to meso-zeaxanthin. The amount of these carotenoids in the retina, macular pigment optical density (MPOD) can be measured non-invasively.
It is unfortunate but many people, especially in Europe and North America, eat few fruits and vegetables. Consequently, their dietary intake of lutein and zeaxanthin is low. In a year-long study of individuals with low MPOD, Nolan and colleagues measured statistically improvements in contrast sensitivity and retinal concentrations of these carotenoids among healthy adults who were randomized to receive carotenoid supplementation (22 mg/d). Dietary supplementation increased serum lutein, zeaxanthin and meso-zeaxanthin concentrations approximately 5-fold above baseline and MPOD volume increased linearly during the study (from 4000 to 6500).
High plasma concentrations of lutein and zeaxanthin are associated with reduced risk of age-related macular disease (AMD). The addition of lutein and zeaxanthin to the AREDS formulation, a formulation associated with a 34% reduction in risk of AMD, was beneficial among participants with low dietary intake of lutein and zeaxanthin.
As North Americans prepare for a weekend of eye candy (and this advice applies to everyone else too), remember to eat lots of foods rich in lutein and zeaxanthin!
Nolan JM, Power R, Stringham J, Dennison J, Stack J, Kelly D, Moran R, Akuffo KO, Corcoran L, Beatty S. Enrichment of macular pigment enhances contrast sensitivity in subjects free of retinal disease: Central retinal enrichment supplementation trials – Report 1. 2016 Invest Opthal Vis Sci doi: 10.1167/iovs.16-19520
Bernstein PS, Johnson EJ, Neuringer M, Schalch W, Schierle J. Comment on: What is meso-zeaxanthin, and where does it come from? 2014 Eye doi: 10.1038/eye.2013.257
Snodderly DM, Mares JA, Wooten BR, Oxton L, Gruber M, Ficek T. Macular pigment measurement by heterochromatic flicker photometry in older subjects: the Carotenoids and Age-Related Eye Disease Study. 2004 Invest Opthal Vis Sci doi: 10.1167/iovs.03-0762
Delcourt C, Delage M, Barberger-Gateau P, Schalch W, the POLA Study Group. 2006 Invest Opthal Vis Sci doi: 10.1167/iovs.05-1235
Chew EY, Clemons TE, Agron E, Sperduto RD, SanGiovanni JP, Kurinij N, Davis MD, Age-Related Eye Disease Study Research Group. 2013 Opthalmal doi: 10.1016/j.ophtha.2013.01.021
The Age-Related Eye Disease 2 (AREDS2) Research Group. Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration. The Age-Related Eye Disease Study 2 (AREDS2) Randomized Clinical Trial. 2013 JAMA doi: 10.1001/jama.2013.4997