Zeaxanthin belongs to the carotenoids and thus to the secondary plant substances. It is derived from the Greek zea mays “corn” and xanthós “sandy yellow, blond”. Accordingly, maize also gets its intense colour from the high zeaxanthin content. Thus, they are considered fat-soluble pigment dyes and give the plants their yellow-orange to reddish colour. They are bioactive substances that have a health-promoting effect and do not have a life-sustaining nutritional function.
Zeaxanthin does not belong to the provitamins because both ring systems contain oxygen and cannot be converted into vitamin A (retinol) by the human metabolism. The natural occurrence is widespread and, along with others such as alpha- and beta-carotene, lutein, lypcopin and beta-cryptoxanthin, it is the most frequently occurring carotenoid in plant foods. It can be found especially in dark green leafy vegetables such as kale, lettuce, spinach, parsley and turnip greens. Here, the zeaxanthin content can vary greatly depending on the season, variety and also which part of the plant is used. For example, the outer leaves of a cabbage or head of lettuce contain significantly more zeaxanthin than the inner leaves of the plant. It also has a protective effect in the plant. In order not to be damaged by high radiation intensity, the plant can use zeaxanthin in the conversion of light into heat.
Occurrence in the human body
Zeaxanthin and lutein occur together in the body because they are structurally hardly different as carotenoids and are closely related to each other. We can find them in fatty tissue, lungs, liver and skin as well as in testicles and ovaries. Both compounds also occur naturally in the lens and retina of the human eye and in the so-called yellow spot (macula lutea). This is the area of the retina with the greatest density of photoreceptors and is responsible for central vision.
Zeaxanthin has a fat-soluble character and is absorbed during fat digestion in the upper small intestine.