ABSTRACT
Epidemiological studies comprise one of several types of scientific approaches that can be used to understand whether the macular carotenoids, lutein and zeaxanthin/ meso-zeaxanthin (L and Z), might protect against the development and worsening of age-related macular degeneration (AMD) in the general population. These are generally observations made in large samples of free-living populations, who often represent a variety of genetic and environmental attributes and may be followed over longer periods of time than are possible in clinical trials. Thus, results from epidemiological studies, together with results from other study types in animals, cells, and people, provide a more complete body of evidence for making sound public health or clinical recommendations than results from single types of studies.
