Dietary Carotenoids Lutein and Zeaxanthin Change Brain Activation in Older Adult Participants: A Randomized, Double-Masked, Placebo-Controlled Trial.
Ceravolo SA, Hammond BR, Oliver W, Clementz B, Miller LS, Renzi-Hammond LM.
Mol Nutr Food Res. 2019 Apr 5:e1801051. doi: 10.1002/mnfr.201801051.

Lutein Complex Supplementation Increases Ocular Blood Flow Biomarkers in Healthy Subjects.
Harris A, Siesky B, Huang A, Do T, Mathew S, Frantz R, Gross J, Januleviciene I, Verticchio Vercellin AC.
Int J Vitam Nutr Res. 2019 Apr 1:1-8. doi: 10.1024/0300-9831/a000576.

Dietary Lutein Plus Zeaxanthin Intake and DICER1 rs3742330 A > G Polymorphism Relative to Colorectal Cancer Risk.
Kim J, Lee J, Oh JH, Chang HJ, Sohn DK, Kwon O, Shin A, Kim J.
Sci Rep. 2019 Mar 4;9(1):3406. doi: 10.1038/s41598-019-39747-5.

Lutein Inhibits Cell Growth and Activates Apoptosis via the PI3K/AKT/mTOR Signaling Pathway in A549 Human Non-Small-Cell Lung Cancer Cells.
Zhang WL, Zhao YN, Shi ZZ, Cong D, Bai YS.
J Environ Pathol Toxicol Oncol. 2018;37(4):341-350. doi: 10.1615/JEnvironPatholToxicolOncol.2018027418.

Lutein as an Ingredient in Pediatric Nutritionals.
Long AC, Kuchan M, Mackey AD.
J AOAC Int. 2019 Feb 22. doi: 10.5740/jaoacint.19-0014.

Liberation of lutein from spinach: Effects of heating time, microwave-reheating and liquefaction.
Chung RWS, Leanderson P, Gustafsson N, Jonasson L.
Food Chem. 2019 Mar 30;277:573-578. doi: 10.1016/j.foodchem.2018.11.023. Epub 2018 Nov 3.

The effects of lutein on optic nerve injury induced by ethambutol and isoniazid: an experimental study.
Karakurt Y, Süleyman H, Keskin Cimen F, Tasli G, Ucak T, Icel E, Kurt N.
Cutan Ocul Toxicol. 2019 Jun;38(2):136-140. doi: 10.1080/15569527.2018.1539010. Epub 2018 Nov 26.

Lutein prevents corticosterone-induced depressive-like behavior in mice with the involvement of antioxidant and neuroprotective activities.
Zeni ALB, Camargo A, Dalmagro AP.
Pharmacol Biochem Behav. 2019 Apr;179:63-72. doi: 10.1016/j.pbb.2019.02.004. Epub 2019 Feb 17.

Modulation of mitochondrial respiration underpins neuronal differentiation enhanced by lutein.
Xie K, Ngo S, Rong J, Sheppard A.
Neural Regen Res. 2019 Jan;14(1):87-99. doi: 10.4103/1673-5374.243713.

Development and evaluation of lutein loaded alginate microspheres with improved stability and antioxidant.
Huang J, Bai F, Wu Y, Ye Q, Liang D, Shi C, Zhang X.
J Sci Food Agric. 2019 Apr 29. doi: 10.1002/jsfa.9766.

Macular Xanthophylls and Event-Related Brain Potentials among Overweight Adults and Those with Obesity.
Edwards CG, Walk AM, Cannavale CN, Thompson SV, Reeser GE, Holscher HD, Khan NA.
Mol Nutr Food Res. 2019 Feb 28:e1801059. doi: 10.1002/mnfr.201801059.

Serum Lutein is related to Relational Memory Performance.
Cannavale CN, Hassevoort KM, Edwards CG, Thompson SV, Burd NA, Holscher HD, Erdman JW Jr, Cohen NJ, Khan NA.
Nutrients. 2019 Apr 2;11(4). pii: E768. doi: 10.3390/nu11040768.

Hydroalcoholic extract of Tagetes erecta L. flowers, rich in the carotenoid lutein, attenuates inflammatory cytokine secretion and improves the oxidative stress in an animal model of ulcerative colitis.
Meurer MC, Mees M, Mariano LNB, Boeing T, Somensi LB, Mariott M, da Silva RCMVAF, Dos Santos AC, Longo B, Santos França TC, Klein-Júnior LC, de Souza P, de Andrade SF, da Silva LM.
Nutr Res. 2019 Mar 8. pii: S0271-5317(18)31059-5. doi: 10.1016/j.nutres.2019.03.005.

Lutein is a fat-soluble xanthophyll carotenoid.

The name "lutein" comes from the Latin "luteus" meaning "yellow". This refers to the yellow color of lutein.

Synthesis of lutein.

• In plants. Lutein is a xanthophyll pigment that is synthesized in plants. It's an important component of chloroplasts and plays a key role in photosynthesis.
• Through diet. Humans cannot synthesize lutein and so must obtain it through diet. Lutein is found in many leafy green vegetables, like spinach and lettuce, as well as in other foods like eggs.

Natural synthesis of lutein.

• Production of precursors. In the chloroplasts of plants, fatty acid molecules are converted into geranylgeranyl diphosphate (GGPP), an important precursor.
• Formation of carotenoids. The GGPP is converted into phytoene, which is then transformed into lycopene through a series of enzyme reactions.
• Synthesis of lutein. The lycopene is converted into alpha-carotene, which is then transformed into lutein through the action of several enzymes.

It appears in the form of an orange powder.

What it is used for and where

Natural substance found in vegetables with green leaves, egg yolk.

Medical

It is an antioxidant that protects the human eye by filtering out ultraviolet rays and protecting it from degenerative ageing diseases.

It is found in spinach, vegetables, fruit and eggs.

It has antioxidant, anti-cancer, anti-inflammatory properties particularly against retinopathy of prematurity, age-related macular degeneration, cataracts, myopia (1)

Food

Lutein is generally obtained from the plant Tagetes erecta L., which belongs to the Asteraceae family and contains at least 80% carotenoids.

 Lutein is an ingredient included in the list of European food additives as a colour with the number E161b. The Panel on Food Additives noted the lack of reproductive toxicity and chronic toxicity/carcinogenicity studies and therefore, in the uncertainty, applied an ADI (Acceptable Daily Intake) of 1 mg/kg body weight/day (2).

Lutein studies

• Molecular Formula: C₄₀H₅₆O₂
• Molecular Weight: 568.886 g/mol
• CAS: 127-40-2
• EC Number: 204-840-0
• UNII: X72A60C9MT
• PubChem Substance ID 329748359
• MDL number: MFCD08435941
• Beilstein Registry Number: 2068547

Synonyms:

• Luteine
• Bo-Xan
• beta,epsilon-Carotene-3,3'-diol, (3R,3'R,6'R)-
• (3R,3'R,6'R)-beta,epsilon-carotene-3,3'-diol
• ε-carotene-3,3′-diol
• ε-carotene
• α-Carotene-3,3′-diol, β
• all-trans-Xanthophyll
• Xanthophyll
• beta,epsilon-Carotene-3,3'-diol
• NSC 59193

References_____________________________________________________________________

(1) Li LH, Lee JC, Leung HH, Lam WC, Fu Z, Lo ACY. Lutein Supplementation for Eye Diseases. Nutrients. 2020 Jun 9;12(6):1721. doi: 10.3390/nu12061721.

(2) EFSA Scientific Opinion on the re-evaluation of lutein (E 161b) as a food additive  EFSA-Q-2008-787  doi  10.2903/j.efsa.2010.1678