ABSTRACT
Humans cannot biosynthesize carotenoids and are dependent on diet or dietary supplementation for a continuous provision of lutein and zeaxanthin, the two key xanthophylls of the human and nonhuman primate retina. To be enriched in the macula to exert their protective function against photooxidative damage and to contribute to lowering the risk of age-related macular degeneration (AMD), lutein and zeaxanthin must be released from the food matrix or from nutritional supplements, absorbed in the gastrointestinal tract and reach the systemic circulation to be transported into the retina. In other words, they must be bioavailable at the target organ. General bioavailability of xanthophylls, however, is not the topic of this chapter
7.1 Introduction .................................................................................................. 129 7.2 Experiments in Rhesus Monkeys ................................................................. 130
7.2.1 Xanthophyll-Free Status of Animals ................................................ 130 7.2.2 Plasma and Macular Pigment Optical Density Responses to
Supplementation with Xanthophylls ................................................. 131 7.2.3 Vulnerability to Blue Light ............................................................... 131 7.2.4 Conclusions ....................................................................................... 134
7.3 Comparison of Plasma Responses to Two Preparations Containing Either Esterified or Nonesterified Lutein ...................................................... 134 7.3.1 Esterified Versus Nonesterified (“Free”) Lutein ............................... 134 7.3.2 Plasma Lutein Responses ................................................................. 135 7.3.3 Conclusions ....................................................................................... 137
7.4 Comparison of Plasma Responses to Nonesterified Lutein Formulated by Two Different Processes .......................................................................... 138 7.4.1 Starch Versus Alginate Matrix ......................................................... 138 7.4.2 Design of Study ................................................................................ 139 7.4.3 Results ............................................................................................... 140 7.4.4 Conclusions ....................................................................................... 141
References .............................................................................................................. 143
since it has been reviewed numerous times (more recent reviews being Thurnham 2007; Loane, Nolan et al. 2008; Maiani, Castón et al. 2009).
