By Stuart Richer, OD, PhD, FAAO
Department of Veterans Affairs, Chief of Optometry, North Chicago VA Medical Center
The two dietary carotenoids, lutein and zeaxanthin, are “binary stars” helping to enhance visual function in normal and diseased eyes.1 The leading eye condition responsible for loss of vision in aging western societies is age-related macular degeneration (AMD). The National Eye Institutes’ AREDS2 study showed that lutein and zeaxanthin, with FloraGLO® Lutein as the lutein source, lowered the risk of AMD and cataract progression in an at-risk population further than the AREDS1 formula alone.2
Beyond the AREDS2 study, eye doctors now appreciate lutein and zeaxanthin’s dietary adjunct role at every stage of AMD. In addition to reducing the rate of progression, lutein and zeaxanthin may help minimizing the number of intravitreal ocular injections and help improve the patient’s visual quality in late-stage disease.1,3 Our clinical experience suggests that many patients with high lutein and zeaxanthin dietary intake: 1) diminish their risk of an AMD diagnosis, 2) improve both their day and night vision, 3) prevent the development of catastrophic neovascularization and 4) improve remaining visual functioning as low vision patients, post medical treatment.
From AREDS2 we have learned that many patients with AMD also suffer from cognitive as well as visual dysfunction.4 In fact, we now know prospectively in a longitudinal study of approximately 2,400 aged adults (age 77 to 101) that the onset of visual impairment found during an eye examination is associated with both cognitive and physical impairment in men and woman (p<0.001).5 Patients with early Alzheimer’s disease (AD) often have trouble completing a two-page reading task. They may suffer visuospatial dysfunction and have trouble making decisions at traffic intersections. The eye doctor is likely to find one or more vision and ocular / cerebral pathway abnormalities. All of the following are possible: abnormal pupil responses, constricted visual fields, abnormal saccadic extra-ocular eye movements, abnormal contrast sensitivity, misfolded cataract lens proteins, peripheral retinal drusen, changes in the color of the ocular nerve head and the thickness of its neural tissue, and changes in the electro-diagnostic Visual Evoked Potential (VEP) of the eye-brain pathway.6
Both AMD and AD are multifactorial diseases which go hand-in-hand with aging, and well beyond the mere physical presence of retinal drusen and amyloid protein, respectively. As such, leading optometrists, ophthalmologists and PhDs now believe these two progressive diseases require a multimodal epigenetic wellness approach (including the help of lutein and zeaxanthin) against a background of the less common individual genetic risk, i.e. APO4.7 Both micronutrient deficiencies and balanced macronutrient intake must be optimized to avoid insulin resistance. Environmental insults that prime oxidative stress and retinal / neuro-inflammation must be avoided. Finally, environmental and pharmaceutical factors that create mitochondrial neuro-degeneration must be mitigated, while supporting mitochondrial health and longevity proteins with optimal nutrition and supplementation. 8 The ultimate aim is to reach for health rather than combat multiple neurosensory degenerations by optimizing predictive biomarkers.7,9,10
Higher dietary lutein and zeaxanthin intake supports this new multimodal clinical approach of optimizing predictive consensus biomarkers. For example, macular pigment density is lower in patients with type 2 diabetes compared to controls.11 Lutein also improves antioxidant status and lowers inflammation.12 There is 90% correlation between human retinal and occipital cortex concentrations of lutein and zeaxanthin.13 The clinical surrogate for the concentration of lutein and zeaxanthin in the retina is macular pigment optical density (MPOD), which can be easily measured in the clinic.
A decade ago, researchers evaluated the relation between lutein and zeaxanthin status and cognitive function. Healthy older subjects in the Memphis, Tennessee area (aged 76 to 85 years, equal numbers of men and women) were assessed for serum lutein and zeaxanthin, MPOD and various measures of cognitive function. Significantly, MPOD was related to performance on a variety of indexes designed to assess processing speed, accuracy, and completion ability (P < 0.05).14
Quite recently, AREDS2 carotenoid dosing (12 mg FloraGLO Lutein and zeaxanthin) was evaluated in community dwelling older adults of 73.7 +/- 8.2 yrs. of age. Participants receiving the active lutein and zeaxanthin dietary supplement had statistically significant increases in MPOD (p<0.03) and improvements in complex attention (p<0.02) and cognitive flexibility domains (p < 0.04) and a trend in executive function in males (p=0.073) relative to study participants taking the placebo.15
Even more remarkable, dietary supplementation with FloraGLO Lutein and zeaxanthin resulting in higher MPOD was associated with aiding cognitive function in young healthy adults. Daily supplementation in 18 to 30-year-olds resulted in significant improvements in spatial memory (p<0.04), reasoning ability (p<0.05) and complex attention (p<0.04) “above and beyond improvements due to practice effects.”16
In conclusion, the emerging science supports the role of dietary lutein and zeaxanthin in supporting both the visual and cognitive function of young and old.
1. Arunkumar R, Calvo CM, Conrady CD, Bernstein PS, What do we know about the macular pigment in AMD: the past, the present, and the future, Eye (Lond). 2018 May;32(5):992-1004. doi: 10.1038/s41433-018-0044-0. Epub 2018 Mar 26.
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10. www.healthstudiescollegium.org Russell Jaffe, MD, PhD
11. Scanlon G1, Connell P, Ratzlaff M, Foerg B, McCartney D, Murphy A, OʼConnor K, Loughman J, Macular pigment optical density is lower in type 2 diabetes, compared with Type 1 diabetes and normal controls, Retina. 2015 Sep; 35(9):1808-16. doi: 10.1097/IAE.0000000000000551.
12. McMillan DC Maguire D, Talwar D, Relationship between nutritional status and the systemic inflammatory response: micronutrients, Proc Nutr Soc. 2018 Sep 17:1-12. doi: 10.1017/S0029665118002501. [Epub ahead of print]
13. Tanprasertsuk EJ, Li B, Bernstein PS, Vishwanathan R, Johnson MA, Poon L, Johnson EJ, Correction: Relationship between Concentrations of Lutein and StARD3 among Pediatric and Geriatric Human Brain Tissue. PLoS One. 2016 Jul 18;11(7):e0159877. doi: 10.1371/journal.pone.0159877. eCollection 2016
14. Renzi LM, Iannacocone A., Johnson E., Kritchevsky S. The relation between serum xanthophyllls, fatty acids, macular pigment and cognitive function in the Health ABC Study. FASEB J 2008;22:877.5.
15. Hammond BR, Stephen Miller LS Medina, OB Miller. CA Lindbergh, C Mewborn, LM Renzi-Hammond, Effects of lutein/zeaxanthin supplementation on the cognitive function of community dwelling older adults: A Randomized, Double-Masked, Placebo-Controlled Trial, Front. Aging Neurosci. 9:254.doi: 10.3389/fnagi.2017.00254
16. Renzi-Hammond LM, Bovier ER, Fletcher LM , Miller S, Mewborn CM , Lindbergh CA , Baxter JH , Hammond BR, Effects of a Lutein and zeaxanthin Intervention on Cognitive Function: A Randomized, Double-Masked, Placebo-Controlled Trial of Younger Healthy Adults, Nutrients 2017, 9, 1246; doi:10.3390/nu9111246