Changes in Macular Pigment Optical Density Clinical Trial
Official title:
Regional Kale as Source of Lutein and Zeaxanthin to Improve Vision of Patients With Age-related Macular Degeneration - an Alternative to Supplements With Isolated Xanthophylls
The age-related macular degeneration (AMD) is an age-dependent, multi-factorial disease. In
Western industrial countries, it is the main cause of visual impairments. In Germany,
approximately 4.5 million people suffer from AMD. Genetic as well as nutritional aspects are
mainly important in AMD development. Until now, AMD-patients are advised to use supplements
based on the carotenoids lutein and zeaxanthin, comprised in high doses and in isolated form.
Results showing the effects of food items (kale, spinach) rich in lutein on improvement of
vision are scarce. And how much is needed within the diet? Within the planned project, human
intervention studies will investigate whether an oil-based kale extract or fresh kale can be
used to improve vision of AMD-patients and persons aged 50+ (without AMD). The first study
will use volunteers without AMD (>18 y) to investigate if there is a dose-dependent effect of
lutein and zeaxanthin (out of a kale extract) on macular pigment optical density (MPOD). This
study will also compare the bioavailability of the carotenoids from the extract and from a
supplement. A second study (also using volunteers without AMD, >18 y) will compare the
bioavailability of lutein and zeaxanthin from the extract and from kale purée. The third
study will investigate the effect of the oil-based kale extract on improvements of MPOD and
vision of AMD-patients and of a control group (volunteers 50+ without AMD).
Usually, the intestinal absorption of lutein and zeaxanthin is determined by analyzing
changes in concentrations in blood plasma. A fast, non-invasive sampling will be evaluated to
check the efficacy of an increased uptake of lutein. Thus, the project will test the
usability of buccal mucosa cells to detect metabolic changes after an uptake of carotenoids.
Besides, the determination of carotenoid contents in skin will be checked on its use as
biomarker of carotenoids in plasma and macula.
Thus, the planned research project will evaluate two non-invasive markers of exposition on
their usability as markers of absorption of lutein and zeaxanthin in blood and macula. In
addition, the minimally needed dosage of lutein and zeaxanthin for AMD prevention will be
determined to reduce the possible risk of currently recommended doses of these compounds. The
project will also present alternatives (kale extract, kale purée) for AMD prevention and to
improve vision to be used instead of currently used high-dose supplements.
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