What is the Difference Between Lutein and Zeaxanthin

The main difference between lutein and zeaxanthin is that lutein is more prominent at the edges of the retina of the human eye whereas zeaxanthin occurs in the center of the retina.

Generally, lutein and zeaxanthin are two powerful, fat-soluble antioxidants in the carotenoid family known as xanthophyll carotenoids.

Key Areas Covered

1. What is Lutein
– Definition, Characteristics, Function
2. What is Zeaxanthin
– Definition, Characteristics, Function
3. Similarities Between Lutein and Zeaxanthin
– Outline of Common Features
4. Difference Between Lutein and Zeaxanthin
– Comparison of Key Differences

Key Terms

Lutein, Zeaxanthin

What is Lutein

Lutein is a type of carotene pigment related to beta-carotene and vitamin A. It is a major carotenoid that occurs in the human eye; it occurs in the macula and retina of the human eye. The main function of lutein in the human eye is to serve as a light filter, protecting eye tissue from sunlight damage. Egg yolks, spinach, kale, corn, orange pepper, kiwi fruit, grapes, zucchini, and squash are food that contains a considerable amount of lutein. People orally take lutein to prevent eye diseases including cataracts, and diseases that lead to vision loss.

Figure 1: Lutein

Furthermore, lutein is a xanthophyll and it is one of the 600 known carotenoids. It is produced only by plants.  It is more common in leafy green vegetables including spinach, kale, and yellow carrots. Animals and humans ingest lutein by eating plants. In the retina, the macula lutea absorbs lutein from the blood. Apart from that, lutein occurs in egg yolk and animal fats.

What is Zeaxanthin

Zeaxanthin is another type of carotene pigment related to vitamin A and it occurs in the human eye along with lutein. Same as lutein, the main function of zeaxanthin is to serve as a filter to protect the human eye from sunlight damage. Eggs, oranges, grapes, corn, goji berries, mango, orange pepper, and some other vegetables and fruits are foods rich in zeaxanthin. Moreover, some people take zeaxanthin as a supplement for age-related vision loss. Zeaxanthin is also important in eye strain, mental decline, heart disease, breast cancer, cataracts, and many other conditions.

Figure 2: Zeaxanthin

Moreover, zeaxanthin is one of the most common types of carotenoids in nature. More importantly, it gives plants like paprika (made from bell peppers), corn, saffron, goji (wolfberries), and some microorganisms their characteristic color. Green plant leaves contain zeaxanthin in higher amounts. Generally, animals can obtain zeaxanthin from a plant diet. Zeaxanthin supplements are also important for supporting eye health.

Similarities Between Lutein and Zeaxanthin

• In general, lutein and zeaxanthin are two antioxidant nutrients that are fat soluble.
• Moreover, they are xanthophyll carotenoids.
• Generally, these carotenoids are yellow in color and they are responsible for the color of most fruits and vegetables.
• Like beta-carotene, lutein and zeaxanthin do not convert into vitamin A in the body; they incorporate into the cell membrane and other lipoproteins in the body.
• Furthermore, both occur in the tissues of the eye, and in blood, serum, skin, cervix, brain, breast, and adipose tissue.
• In the eye, both lutein and zeaxanthin serve as filters of the eye, blocking out harmful UV rays and other high-energy wavelengths.
• In addition, lutein and zeaxanthin are isomers with the same molecular formula. There are only slight differences in their structure.

Difference Between Lutein and Zeaxanthin

Definition

Generally, lutein refers to a deep yellow pigment of the xanthophyll class, found in the leaves of plants, in egg yolk, and in the corpus luteum while zeaxanthin refers to a deep yellow carotenoid pigment present in the retina of the eye and in some plants, used as a food additive and supplement.

Occurrence in the Eye

Lutein is more prominent at the edges of the retina while zeaxanthin occurs in the center of the retina.

Dietary Sources

Lutein is common in most fruits and vegetables while zeaxanthin occurs in minute quantities in fruits and vegetables.

Conclusion

In brief, Lutein and zeaxanthin are two types of xanthophyll carotenoids. In fact, they are responsible for the yellow color in most fruits and vegetables. Lutein occurs at the edges of the retina of the eye while zeaxanthin occurs in the center of the retina. This is the main difference between lutein and zeaxanthin. Furthermore, in the eye, the main function of lutein and zeaxanthin is to serve as a filter to protect the eye tissue from sunlight damage. 

References:

1. “Lutein: Overview, Uses, Side Effects, Precautions, Interactions, Dosing and Reviews.” WebMD, WebMD.
2. “Zeaxanthin: Overview, Uses, Side Effects, Precautions, Interactions, Dosing and Reviews.” WebMD, WebMD

Image Courtesy:

1. “Luteine – Lutein” By Yikrazuul – Own work (Public Domain) via Commons Wikimedia
2. “Zeaxanthin2” By NEUROtiker – Own Work (Public Domain) via Commons Wikimedia