Carotenoid-based visual cues and roles of carotenoids in human vision are reviewed, with an emphasis on protection by zeaxanthin and lutein against vision loss, and dietary sources of zeaxanthin and lutein are summarized. In addition, attention is given to synergistic interactions of zeaxanthin and lutein with other dietary factors affecting human vision such as antioxidant vitamins, phenolics, and poly-unsaturated fatty acids and the emerging mechanisms of these interactions. Emphasis is given to lipid oxidation products serving as messengers with functions in gene regulation. Lastly, the photo-physics of light collection and photoprotection in photosynthesis and vision are compared and their common principles identified as possible targets of future research. Carotenoids possess functions as diverse as their colors for a review, see [ 1 ]. Carotenoid function as visual cues is matched by roles in 1 visual detection of these cues and 2 protection of the vision process against overly bright light. On the other hand, the carotenoids zeaxanthin and lutein provide essential protection of the eye in humans and many other animals. Moreover, carotenoids are involved in the regulation of life-and-death processes at the cellular level via modulation of signaling networks that control cell division and programmed cell death [ 2 ].
The selection of foods to eat is a complex interplay of vision, taste, smell, and texture. In addition to micro- and macronutrients, plant-based foods also contain several classes of phytochemicals. In many cases, the phytochemicals account for the various colors of foods. Although aesthetically pleasing, the color of foods may mislead consumers as to their phytochemical content, which is particularly true with regard to polyphenols.
Though the effect of baking appeared to be dependent on type of baked product, type of phenolic, recipe and baking conditions, the wholegrain products should be considered good sources of phenolic antioxidants. In general, the ageing processes cause biochemical, physiological and physical changes that are directly or indirectly responsible for the onset of many diseases including cataract and AMD. TPH1 These secondary metabolites are produced for the benefit of the plant rather than for the consumer. The most commonly described cutaneous manifestations accompanying vitamin C deficiency are attributed to the impaired collagen synthesis. Recently an article that traces the modern history of lutein and zeaxanthin in health and diseases of retina identified four areas for further investigation: i ultra-structural localization of xanthophyll affected proteins in the retina, ii genetic analysis-genotyping efforts, iii model system for the metabolism of lutein and zeaxanthin and iv integrated system based approaches to trace the fate of lutein and zeaxanthin, its precursor s and metabolites [ 15 ]. Carotenoid supplementation reduces erythema in human skin after simulated solar radiation exposure. J Dermatol Sci. Dermatol Surg. It would, therefore, be reasonable to explore similar complex-binding protein s in humans and other vertebrates that may be responsible for transportation of lutein and zeaxanthin to the macula. The toxic truth about sugar. Multivitamin-multimineral supplements and eye disease: age-related macular degeneration and cataract.
Published online Apr 9. Thus, egg yolk could be an important dietary source to improve lutein and zeaxanthin status for the prevention of cataracts and AMD in adults. Macular pigment: a review of current knowledge. In a minor group of flavonoids, the phenyl ring is shifted from the 2-position to the 3-position isoflavonoids. A positively charged oxygen atom in the heterocyclic ring produces the color for anthocyanins Fig. A patient with clubbed fingernails or toenails should be evaluated for pulmonary insufficiency. A self-completed questionnaire on risk factors specific to the eye sunlight exposure, television and computer use and dry eye symptoms Ocular Surface Disease Index OSDI 28 was filled at home and brought back on the day of the eye examination. Cancer Causes Control. Basu H.