The role of the carotenoids, lutein and zeaxanthin, in protecting against age-related macular degeneration: A review based on controversial evidence

Nutrition Journal, Dec 2003

Purpose A review of the role of the carotenoids, lutein and zeaxanthin, and their function in altering the pathogenesis of age-related macular degeneration (AMD). Methods Medline and Embase search. Results Recent evidence introduces the possibility that lutein and zeaxanthin, carotenoids found in a variety of fruits and vegetables may protect against the common eye disease of macular degeneration. This potential and the lack to slow the progression of macular degeneration, has fueled high public interest in the health benefits of these carotenoids and prompted their inclusion in various supplements. The body of evidence supporting a role in this disease ranges from basic studies in experimental animals to various other clinical and epidemiological studies. Whilst some epidemiological studies suggest a beneficial role for carotenoids in the prevention of AMD, others are found to be unrelated to it. Results of some clinical studies indicate that the risk for AMD is reduced when levels of the carotenoids are elevated in the serum or diet, but this correlation is not observed in other studies. Published data concerning the toxicity of the carotenoids or the optimum dosage of these supplements is lacking. Conclusion An intake of dietary supplied nutrients rich in the carotenoids, lutein and zeaxanthin, appears to be beneficial in protecting retinal tissues, but this is not proven. Until scientifically sound knowledge is available we recommend for patients judged to be at risk for AMD to: alter their diet to more dark green leafy vegetables, wear UV protective lenses and a hat when outdoors. Future investigations on the role of nutrition, light exposure, genetics, and combinations of photodynamic therapy with intravitreal steroid (triamcinolone-acetonide) injections hold potential for future treatment possibilities.

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The role of the carotenoids, lutein and zeaxanthin, in protecting against age-related macular degeneration: A review based on controversial evidence

Nutrition Journal The role of the carotenoids, lutein and zeaxanthin, in protecting against age-related macular degeneration: A review based on controversial evidence Maneli Mozaffarieh 0 Stefan Sacu 0 Andreas Wedrich andreas.wedrich@akh- 0 0 Address: Department of Ophthalmology, University of Vienna , Austria Purpose: A review of the role of the carotenoids, lutein and zeaxanthin, and their function in altering the pathogenesis of age-related macular degeneration (AMD). Methods: Medline and Embase search. Results: Recent evidence introduces the possibility that lutein and zeaxanthin, carotenoids found in a variety of fruits and vegetables may protect against the common eye disease of macular degeneration. This potential and the lack to slow the progression of macular degeneration, has fueled high public interest in the health benefits of these carotenoids and prompted their inclusion in various supplements. The body of evidence supporting a role in this disease ranges from basic studies in experimental animals to various other clinical and epidemiological studies. Whilst some epidemiological studies suggest a beneficial role for carotenoids in the prevention of AMD, others are found to be unrelated to it. Results of some clinical studies indicate that the risk for AMD is reduced when levels of the carotenoids are elevated in the serum or diet, but this correlation is not observed in other studies. Published data concerning the toxicity of the carotenoids or the optimum dosage of these supplements is lacking. Conclusion: An intake of dietary supplied nutrients rich in the carotenoids, lutein and zeaxanthin, appears to be beneficial in protecting retinal tissues, but this is not proven. Until scientifically sound knowledge is available we recommend for patients judged to be at risk for AMD to: alter their diet to more dark green leafy vegetables, wear UV protective lenses and a hat when outdoors. Future investigations on the role of nutrition, light exposure, genetics, and combinations of photodynamic therapy with intravitreal steroid (triamcinolone-acetonide) injections hold potential for future treatment possibilities. age-related macular degeneration (AMD)carotenoidsvitamin supplements - ina are lutein and zeaxanthin [1,2]. Similar to -carotene, these pigments are found in various coloured fruits and green leafy vegetables. Of the 40 to 50 carotenoids typically consumed in the human diet [3,4], lutein and zeaxanthin, are deposited at an up to 5 fold higher content in the macular region of the retina [1] as compared to the peripheral retina. Zeaxanthin is preferentially accumulated in the foveal region [2,5], whereas lutein is abundant in the perifoveal region. These pigments are collectively referred to as the macular pigment (MP). Although the role of the macular pigment remains uncertain, several functions have been hypothesised and these include limitation of the damaging photo-oxidative effects of blue light through its absorption [6-8], reduction of the effects of light scatter and chromatic aberration on visual performance, [9,10], and protection against the adverse effects of photochemical reactions because of the antioxidant properties of the carotenoids [5,11,12]. Age related macular degeneration (AMD) is the leading cause of irreversible vision loss in the elderly population in the USA and the Western world. It is estimated that 1.6% of the population in the 50-to 65-year-old age group is affected, rising to 30% in the over-75-year-old age group. As the proportion of the elderly in our population increases, the public health impact of AMD will become even more severe Although the aetiopathogenesis of AMD remains a matter of debate, there is a growing body of evidence to indicate that oxidative damage plays a role [13,14]. Consequently, the possibility that the absorption characteristics and antioxidant properties of macular pigment confer protection against age-related macular degeneration has been postulated [12,15] and it has further been hypothesised that dietary supplementation with lutein and / or zeaxanthin might protect the retina and / or delay the progression of age-related macular degeneration [12,16-18]. Supplementation with foods [19-21] or supplements rich in lutein or zeaxanthin has been reported to increase macular pigment density in most, but not all, human subjects [19,21,22]. Yet despite the possible importance of these carotenoids in modulating the course of age-related macular degeneration, critical evidence of beneficial effect has not been found, and the role that these carotenoid supplements play in patients with age-related macular degeneration, or those at risk of developing the disease, remains unproved. In this article we review the current literature present on carotenoids and focus particularly on the controversial evidence that retinal carotenoids are protective against age-related macular degeneration. Results Age related macular degeneration Definition an (...truncated)


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Maneli Mozaffarieh, Stefan Sacu, Andreas Wedrich. The role of the carotenoids, lutein and zeaxanthin, in protecting against age-related macular degeneration: A review based on controversial evidence, Nutrition Journal, 2003, pp. 20, 2, DOI: 10.1186/1475-2891-2-20