What is the Difference Between Lutein and Zeaxanthin

The key difference between lutein and zeaxanthin is that lutein is a common carotenoid molecule that is found in most fruits and vegetables, while zeaxanthin is a carotenoid molecule that is present in minute quantities in most fruits and vegetables.

Lutein and zeaxanthin are two carotenoid molecules. They are found in many fruits and vegetables. Lutein and zeaxanthin have very important physiological functions. They may provide protection against the common eye disease of macular degeneration. This factor has fuelled high public interest in their health benefits and has already prompted their inclusion in various supplements.

CONTENTS

1. Overview and Key Difference
2. What is Lutein 
3. What is Zeaxanthin
4. Similarities – Lutein and Zeaxanthin
5. Lutein vs Zeaxanthin in Tabular Form
6. Summary – Lutein vs Zeaxanthin

What is Lutein?

Lutein is a common carotenoid molecule found in most fruits and vegetables. It is a xanthophyll and one of the 600 naturally occurring carotenoid molecules. It is synthesized only by plants, like other xanthophylls. High quantities of lutein are found in green leafy vegetables like spinach, kale, and yellow carrots. In green plants, during photosynthesis, xanthophylls help to modulate light energy and serve as a non-photochemical quenching molecule to deal with triplet chlorophyll. Lutein is also found in egg yolks and animal fats. Moreover, animals obtain lutein through consuming plants. Lutein is present in the macula lutea of the retina in humans. It is absorbed into the macula lutea through the blood.

Lutein is isomeric with zeaxanthin. It differs from zeaxanthin due to the presence of one less double bond in its structure. The distinctive light absorbing property of lutein is due to the long chromophore of conjugated double bonds (polyene chain). Lutein is a lipophilic molecule that is generally insoluble in water. Furthermore, it has been discovered that lutein decreases the risk of age-related macular degeneration and prevents cataract development. Lutein is used as a food additive, a coloring agent, and a dietary supplement. In addition, it is also used in pharmaceuticals, in pet food, and in animal and fish feed. The newer applications include oral and topical products for skin health.

What is Zeaxanthin?

Zeaxanthin is a carotenoid molecule that is present only in minute quantities in most fruits and vegetables. It is synthesized in plants and some microorganisms. This pigment gives paprika, corn saffron, goji, and many other plants their characteristic color. It also gives some microbes their characteristics color as well. Xanthophylls like zeaxanthin are found in the highest quantity in the leaves of most green plants. It is also used in the xanthophyll cycle.

Zeaxanthin is one of the two xanthophyll carotenoid molecules contained within the retina of the human eye. Recent research has suggested that zeaxanthin decreases the risk of age-related macular degeneration and prevents cataract development. Furthermore, it is also used as a food additive and food dye.

What are the Similarities Between Lutein and Zeaxanthin?

• Lutein and zeaxanthin are two carotenoid molecules.
• Both are isomers and have the chemical formula C₄₀H₅₆O₂.
• They are potent antioxidants.
• Both are found in many fruits and vegetables.
• Both are used in the xanthophyll cycle.
• In photosynthesis, both help to modulate light energy and serve as a non-photochemical quenching molecule to deal with triplet chlorophyll.
• Both are present in the human retina.
• They protect the human eye by reducing macular degeneration and preventing cataracts.
• They are also used as food additives commercially.

What is the Difference Between Lutein and Zeaxanthin?

Lutein is a common carotenoid molecule that is found in most fruits and vegetables, while zeaxanthin is a carotenoid molecule that is present only in minute quantities in most fruits and vegetables. Thus, this is the key difference between lutein and zeaxanthin. Furthermore, lutein has 10 double bonds in the structure, while zeaxanthin has 11 double bonds in the structure.

The below infographic presents the differences between lutein and zeaxanthin in tabular form for side-by-side comparison.

Summary – Lutein vs Zeaxanthin

Lutein and zeaxanthin are two carotenoid molecules. Both are isomers and have the chemical formula C₄₀H₅₆O₂. The key difference between lutein and zeaxanthin is that lutein is commonly found in most fruits and vegetables, while zeaxanthin is present only in minute quantities in most fruits and vegetables.

Reference:

1. Mozaffarieh, Maneli, et al. “The Role of the Carotenoids, Lutein and Zeaxanthin, in Protecting against Age-Related Macular Degeneration: A Review Based on Controversial Evidence.” Nutrition Journal, BioMed Central, 11 Dec. 2003.
2. “Zeaxanthin: Overview, Uses, Side Effects, Precautions, Interactions, Dosing and Reviews.” WebMD.

Image Courtesy:

1. “Lutein 2D” (CC0-1.0) via Commons Wikimedia
2. “Cleavage of Zeaxanthin to Crocetin and Safranal” By NadirSH – Own work (CC BY-SA 4.0) via Commons Wikimedia