Lutein and Zeaxanthin

Lutein is a xanthophyll carotenoid, its structural isomers include zeaxanthin and meso-zeaxanthin ¹. The names of both reflect their natural yellow colour (the Latin ‘luteus’ and the Greek ‘xanthos’ mean yellow). Lutein and zeaxanthin on the market are mostly extracted from marigold flowers (Tagetes erecta) ^2,3. Both can also be obtained from green leafy vegetables (for eg. kale, spinach, and Brussels sprouts), sweet corn, egg yolk and fruits like avocado and kiwi ¹.

Lutein usually exists in plants as an ester, which in humans can be hydrolyzed into free lutein. Lutein esters are generally less sensitive to degradation than free lutein and have equal bioavailability as free lutein ^3,4. Lutein and zeaxanthin are not produced by the body, hence they need to be obtained through food or supplement.

Fun Facts

These carotenoids are highly concentrated in the human eyes and brain, comprising 80% to 90% ¹. They are exclusive carotenoids in the neural retina and lens. These carotenoids do not have vitamin A activity like provitamin A carotenoids (for eg. α-carotene, ß-carotene, and ß-cryptoxanthin) ¹.

Published Health Benefits

1. Eye health

• Lutein and zeaxanthin are highly found in the macular (major part of retina), they are potent antioxidants which help absorb blue light thus protecting the retina from light-related damage and reduce light scatter ^5,6.
• Researches have shown supplementing with lutein and zeaxanthin improved visual acuity and contrast sensitivity which is affected by aging or disease ¹.
• These carotenoids also help protect against age-related macular degeneration, nuclear cataract, glaucoma and diabetic retinopathy ^5,6.

2. Cognitive functions

• Lutein and zeaxanthin have been shown to enhance visual processing speed and visual motor behaviour ^1,7. Research has shown lutein supplementation significantly improved some cognitive functions such as verbal fluency, memory scores and efficient learning among elderly ⁵. In-vitro study also showed the potential benefits of lutein in protecting against Alzheimer’s diseases ⁵.
  

3. Heart health

• Research showed supplementing with lutein was associated with significant reduction in LDL cholesterol and triglycerides levels ⁵.
  
• Higher lutein intake also contributes to better cardiovascular health and reduces risk of coronary heart disease and stroke ⁵.
  

4. Skin health

• Lutein and zeaxanthin have the photoprotective action and strong antioxidant properties which can reduce pigmentation, promote skin lightening and improve skin health conditions ⁸.
  

Recommended Daily Dose

Recommended dose of lutein is 5-20mg/day, while zeaxanthin is 1-4mg/day. The US National Eye Institute supported the golden ratio of lutein:zeaxanthin is 5:1 to benefit vision health ⁹.

References:

1. Mares, J. (2016). Lutein and Zeaxanthin Isomers in Eye Health and Disease. Annu Rev Nutr, 36, 571-602. doi: 10.1146/annurev-nutr-071715-051110

2. Šivel, M., Kráčmar, S., Fišera M Klejdus, B., & Kubáň, V. (2014). Lutein Content in Marigold Flower (Tagetes Erecta L.) Concentrates Used For Production of Food Supplements. Czech Journal Of Food Sciences, 32(6), 521-525. doi: 10.17221/104/2014-cjfs

3. Gombač, Z., Črnivec, I., Skrt, M., Istenič, K., Knafelj, A. K., Pravst, I., & Ulrih, N. P. (2021). Stabilisation of Lutein and Lutein Esters with Polyoxyethylene Sorbitan Monooleate, Medium-Chain Triglyceride Oil and Lecithin. Foods (Basel, Switzerland), 10(3), 500. https://doi.org/10.3390/foods10030500

4. Bowen, P. E., Herbst-Espinosa, S. M., Hussain, E. A., & Stacewicz-Sapuntzakis, M. (2002). Esterification does not impair lutein bioavailability in humans. The Journal of nutrition, 132(12), 3668–3673. https://doi.org/10.1093/jn/132.12.3668

5. Buscemi, S., Corleo, D., Di Pace, F., Petroni, M. L., Satriano, A., & Marchesini, G. (2018). The Effect of Lutein on Eye and Extra-Eye Health. Nutrients, 10(9), 1321. https://doi.org/10.3390/nu10091321

6. Li, L. H., Lee, J. C., Leung, H. H., Lam, W. C., Fu, Z., & Lo, A. (2020). Lutein Supplementation for Eye Diseases. Nutrients, 12(6), 1721. https://doi.org/10.3390/nu12061721

7. Bovier, E. R., Renzi, L. M., Hammond, B. R (2014). A Double-Blind, Placebo-Controlled Study on the Effects of Lutein and Zeaxanthin on Neural Processing Speed and Efficiency. PLoS ONE, 9(9): e108178. doi: 10.1371/journal.pone.0108178

8. Juturu, V., Bowman, J. P., & Deshpande, J. (2016). Overall skin tone and skin-lightening-improving effects with oral supplementation of lutein and zeaxanthin isomers: a double-blind, placebo-controlled clinical trial. Clinical, cosmetic and investigational dermatology, 9, 325–332. https://doi.org/10.2147/CCID.S115519

9. AREDS2 Research Group, Chew, E. Y., Clemons, T., SanGiovanni, J. P., Danis, R., Domalpally, A., McBee, W., Sperduto, R., & Ferris, F. L. (2012). The Age-Related Eye Disease Study 2 (AREDS2): study design and baseline characteristics (AREDS2 report number 1). Ophthalmology, 119(11), 2282–2289. https://doi.org/10.1016/j.ophtha.2012.05.027