Zeaxanthin
Introduction
Zeaxanthin is a naturally occurring carotenoid found in many fresh fruits and vegetables. It is one of the most common carotenoid alcohols found in nature and is known for its important role in the xanthophyll cycle, which is involved in the photosynthesis process in plants. Zeaxanthin is also a powerful antioxidant, which can help protect the body from damage by free radicals.
Structure and Properties
Zeaxanthin is a member of the xanthophylls, which are a class of oxygen-containing carotenoids. It is structurally similar to lutein and beta-carotene, with the main difference being the location of the double bonds in the cyclic end groups of the molecules. Zeaxanthin has a molecular formula of C40H56O2 and a molecular weight of 568.87 g/mol.
Biosynthesis
Zeaxanthin is synthesized from beta-carotene in a two-step process. First, beta-carotene is hydroxylated by the enzyme beta-carotene hydroxylase to produce zeaxanthin. This reaction is followed by the isomerization of zeaxanthin to produce 3R,3'R-zeaxanthin.
Dietary Sources
Zeaxanthin is found in a wide variety of fruits and vegetables, including spinach, kale, broccoli, peas, and brussels sprouts. It is also found in egg yolks and certain types of seafood. The highest concentrations of zeaxanthin are found in orange and yellow fruits and vegetables, such as oranges, papayas, and corn.
Health Benefits
Zeaxanthin has been associated with numerous health benefits, particularly in relation to eye health. It is one of the two primary xanthophyll carotenoids contained within the retina of the eye, and research suggests that it may play a protective role against age-related macular degeneration (AMD), a leading cause of vision loss in older adults. Zeaxanthin may also help protect the skin from UV damage, improve cognitive function, and reduce the risk of certain types of cancer.
Safety and Side Effects
Zeaxanthin is generally considered safe when consumed in amounts typically found in foods. However, excessive intake of zeaxanthin from supplements may lead to a condition known as carotenodermia, which is characterized by yellowing of the skin.