KEMIN011838-03-2nd Pentvision White Paper.indd 1
2 Exploring the Lutein Link in Ocular and Neural Health Lutein, a dietary carotenoid common to fruits and vegetables, has strong support for its role in ocular health throughout the lifespan (1). The evidence to date indicates that lutein may influence early maturation of the retina (2,3) as well as decrease the risk of age-related eye diseases (1). Lutein has recently been recognized to function in another neural tissue the brain. OH HO Figure 1: Lutein (from the Latin luteus, meaning yellow ) is a xanthophyll (yellow pigment) and one of 600 known naturally occurring carotenoids (organic pigments). Lutein and Cognitive Performance As with eye tissue, lutein is selectively taken up into brain tissue where it is the predominant carotenoid in both infant and adult brains (4,5). Higher brain levels of lutein are related to better cognitive function in older adults (5). Of interest is that lutein concentrations in the macula of the retina (macular pigment) are significantly correlated with levels in matched brain tissue (6,7). Therefore, macular pigment density a quick, non-invasive measure of lutein in neural tissue can be used as a biomarker of lutein in brain tissue. This likely explains the observations among several research groups that macular pigment density in adults is significantly related to a better cognitive performance (8 11). Figure 2: Lutein levels in macular pigment (center) are significantly correlated with lutein levels in matched brain tissue. KEMIN011838-03-2nd Pentvision White Paper.indd 2
3 Zeaxanthin Occurs in the Brain. Meso-Zeaxanthin Does Not. In addition to lutein, macular pigment is also composed of two other carotenoids of very similar structure to lutein: zeaxanthin and meso-zeaxanthin (12). As with lutein, zeaxanthin is common to fruits and vegetables and is found in the same body tissues as lutein. Zeaxanthin is also recognized as having a role in the reduction in risk of age-related diseases (13). Lutein and zeaxanthin concentrations in the brain reflect levels in the circulation, which is an indicator of their intakes (5). Meso-zeaxanthin is formed exclusively from lutein in the retina (14). Meso-zeaxanthin is not detected in human brain tissue (7) and is not common to our diet (15). Lutein and Cognitive Development in Children Lutein s effects on cognition in early life and childhood have only recently been considered. However, such a role is particularly compelling given that among the carotenoids lutein is preferentially taken up into cord blood (16) and breast milk (17,18). In pediatric brains, the relative contribution of lutein to the total carotenoids is twice that found in adults (4,5), accounting for more than half the concentration of total carotenoids. The greater proportion of lutein in pediatric brains suggests a need for lutein during neural development as well. These beneficial effects of lutein in cognitive health in early life likely persist into childhood. As in adults, recent studies report that macular pigment density was significantly related to better memory and academic performance in children between the ages of 8-10 years (19,20). The proposed mechanisms by which lutein may exert its effect include its role as an antioxidant and anti-inflammatory. In fact, in a randomized, double-blind, placebo-controlled study of healthy-term newborns, supplemental lutein (as FloraGLO Lutein) was found to significantly increase serum measures of antioxidant activity (21). The brain is especially in need for antioxidants because of its high metabolic rate. In addition, cellular membranes of brain tissues are rich in polyunsaturated fatty acids (22), which are highly oxidizable. These same membranes are rich in lutein (but not other carotenoids) (22). Thus, the pairing of an antioxidant in a highly oxidizable environment would be of benefit in brain tissue. Macular pigment density is significantly related to better memory and academic performance in children between the ages of 8-10 years (19,20). KEMIN011838-03-2nd Pentvision White Paper.indd 3
4 The Importance of Diet in Lutein and Zeaxanthin Intake Lutein Zeaxanthin Lutein and zeaxanthin are not synthesized in the body and must be consumed for eventual uptake into neural tissues. Unfortunately, most Americans may not get enough lutein/zeaxanthin. In the U.S., the average adult consumes less than 2 mg per day, with even lower intakes in infancy and childhood (23). While currently there is no recommended dietary intake for lutein/zeaxanthin, the epidemiological and interventional evidence suggests that at least 6-12 mg per day is important for ocular health in adults (24). Additionally, an intervention study in adults reported supplementation with 12 mg/d of lutein and ~0.5 mg zeaxanthin/d for 4 months significantly improved cognitive function in older adults (25). For those who do not consume lutein- and zeaxanthin-rich foods, supplementation may be warranted to fill the gap. Supplementation with lutein and zeaxanthin has been effective in increasing lutein and zeaxanthin concentrations in non-human and human primate tissues, including the eye and brain (6,14). While there is some evidence that the combination of these carotenoids along with meso-zeaxanthin can increase macular pigment density (27), supplementation with meso-zeaxanthin needs some thought. Since meso-zeaxanthin is not found in the normal diet (15), is made from lutein exclusively in the eye, has not been reported to be in human tissues outside of the macula and, importantly, that carotenoids compete for intestinal absorption and tissue uptake, supplementation with meso-zeaxanthin, particularly in infancy and childhood during neural development, requires careful consideration. SPINACH KALE COLLARDS BROCCOLI AVOCADO CORN EGGS ORANGE PEPPERS Table 1: Richest dietary sources of lutein and zeaxanthin, respectively. The ratio of lutein to zeaxanthin in foods tends to be 5:1. About the Author Elizabeth J. Johnson, PhD, is a Scientist I at the Jean Mayer USDA Human Nutrition Research Center on Aging and an Associate Professor at the Friedman School of Nutrition and Science Policy at Tufts University. Email address: elizabeth.johnson@tufts.edu Citations available upon request from floraglo@kemin.com Kemin Industries, Inc. and its group of companies 2017. All rights reserved. Trademarks of Kemin Industries, Inc., U.S.A. DSM Nutritional Products 2017. FloraGLO is distributed by DSM Nutritional Products. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. KEMIN011838-03-2nd Pentvision White Paper.indd 4
Kemin Industries, Inc. and its group of companies 2017. All rights reserved. Trademarks of Kemin Industries, Inc., U.S.A. DSM Nutritional Products 2017. FloraGLO is distributed by DSM Nutritional Products. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. KEMIN011838-03-2nd Pentvision White Paper.indd 5