What are lutein and zeaxanthin, and which foods have them?

Lutein and zeaxanthin are pigments in the carotenoid family, the same family as beta-carotene and astaxanthin. They share one chemical formula, C40H56O2, and differ only in one ring at the end of the molecule. Plants make them, so the richest foods are dark green leafy vegetables: raw spinach has about 12,200 µg per 100 g. Egg yolk, peas, pumpkin, zucchini and sweet corn also contain them. Commercially, lutein is extracted mainly from marigold petals. A study of adults in Bangkok estimated an average intake of about 3 mg a day.

In short:

• What they are: carotenoids (xanthophylls), isomers with the formula C40H56O2
• Highest in food: dark leafy greens such as spinach, turnip greens, kale and basil
• Other sources: egg yolk, peas, zucchini, pumpkin, broccoli, sweet corn
• Thai foods: water dropwort, Chinese bitter gourd, Chinese kale, morning glory, amaranth
• Commercial source: marigold (Tagetes erecta) petals
• Thai RDI: none

This article explains what the two pigments are, how much of them foods contain, and how much people in Thailand eat. For the wider carotenoid family, see What is astaxanthin, and where does it come from?

What are lutein and zeaxanthin?

The NIH Office of Dietary Supplements describes provitamin A carotenoids, such as beta-carotene, as plant pigments. Lutein and zeaxanthin belong to the same carotenoid family, but PubChem classifies them as carotenols, carotenoids that carry hydroxyl (-OH) groups and so contain oxygen as well as carbon and hydrogen. Carotenoids of this kind are called xanthophylls.

Two pigments with the same formula

PubChem, the chemistry database of the US National Library of Medicine, describes lutein as a carotenol and lists its roles as a plant metabolite and a food colouring. Lutein and zeaxanthin have exactly the same atoms, so they are isomers.

Where the difference is

Both molecules are a long chain of alternating double bonds with a ring at each end. The words in the chemical name describe the rings. "Beta" and "epsilon" are two ring types that differ in where one double bond sits. Lutein has one of each, which is why it is called beta,epsilon-carotene. Zeaxanthin has two beta rings, the same ring type as beta-carotene, which is why it is called beta,beta-carotene. The "-3,3'-diol" part means one hydroxyl group on each ring.

Are lutein and zeaxanthin turned into vitamin A?

No. The NIH Office of Dietary Supplements (ODS) explains that the body converts provitamin A carotenoids, such as beta-carotene, into vitamin A, while other carotenoids in food, such as lycopene, lutein and zeaxanthin, are not converted and are called non-provitamin A carotenoids.

Why this matters when reading food tables

Because they are not converted into vitamin A, lutein and zeaxanthin do not count as vitamin A. A food can be high in lutein but low in vitamin A, and the reverse.

Which foods have the most lutein and zeaxanthin?

The US Department of Agriculture's FoodData Central database (SR Legacy) reports lutein and zeaxanthin together as one value. The figures below are per 100 g of the food as described, from American samples.

Lutein and zeaxanthin per 100 g (FoodData Central)

Green leaves come first

The foods highest in lutein and zeaxanthin are green leaves. In the same database, carrot, papaya and mango have far less (256, 89 and 23 µg per 100 g) than spinach or kale. Pak choi, also a green vegetable, has only 40 µg, so the kind of vegetable matters more than whether it is green.

Raw and cooked

Spinach has 12,198 µg per 100 g raw and 11,308 µg per 100 g boiled and drained in FoodData Central. Cooked spinach shrinks: the database gives 30 g for a cup of raw spinach and 180 g for a cup of boiled spinach.

How much is in a usual serving?

The next table uses the serving weights given in FoodData Central. The values in this table are calculated by multiplying the FoodData Central value per 100 g by the serving weight.

Lutein and zeaxanthin per serving

Eggs: all of it is in the yolk

FoodData Central lists 1,094 µg per 100 g of raw egg yolk and 0 µg in egg white. The pigment in eggs is in the yolk.

Which Thai vegetables contain lutein?

Indigenous vegetables from southern Thailand

A 2015 study from the Institute of Nutrition, Mahidol University, analysed 15 indigenous vegetables and fruits collected in southern Thailand. Water dropwort (ผักชีล้อม, Oenanthe javanica) had the highest lutein, at 7,439.11 µg per 100 g. The researchers also found that Mon-pu (ผักมันปู, Glochidion perakense) and young cashew leaves were rich sources of lutein and beta-carotene. The study collected samples from southern Thailand only.

Vegetables Bangkok residents eat most

A study by researchers from Kasetsart University and Mahidol University used a list of 44 foods high in lutein and zeaxanthin commonly eaten in urban Thailand. The foods that supplied the most lutein and zeaxanthin in their participants' diets were:

Everyday Thai vegetables such as bitter gourd, Chinese kale and morning glory, and eggs, are what provide most of the lutein in this group's diet.

How much lutein do Thai people eat?

A 2020 study in Bangkok and nearby provinces

The same study recruited 120 adults aged 40 to 72 living in Bangkok and nearby provinces, between July and November 2020. A semi-quantitative food frequency questionnaire estimated an average intake of lutein and zeaxanthin of 3.03 mg a day, with a standard deviation of 2.65 mg, so intakes varied widely between people.

Limits of the estimate

The authors note that a food frequency questionnaire relies on self-report, which affects reliability, and the participants were from the central region only, so the figure may not apply to other parts of Thailand.

Where does the lutein used in the food industry come from?

Marigold petals

A 2023 study from Konkuk University in Korea describes marigold (ดาวเรือง, Tagetes spp.) petals as the most important source of carotenoids, especially lutein esters, for producing natural lutein for food and feed. Across ten marigold cultivars, total carotenoids ranged from 25.62 to 2,723.11 µg per gram of fresh petals.

Free lutein and lutein esters

In marigold petals, most lutein is bound to fatty acids as esters. The Korean study found that lutein diesters, with a fatty acid on each hydroxyl group, such as lutein dipalmitate, were the main forms. The esters and free lutein are the same pigment, with or without fatty acids attached.

Lutein as a food colour

In the European Union, lutein is a food additive (colour) with the code E 161b. The European Food Safety Authority (EFSA) re-evaluated it in 2010, based on lutein from Tagetes erecta containing at least 80% carotenoids, of which 79% lutein and 5% zeaxanthin.

Is there a recommended daily amount of lutein and zeaxanthin?

Lutein and zeaxanthin are not nutrients with a Thai Reference Daily Intake (Thai RDI), so there is no recommended daily amount in Thailand. The values that exist are safety benchmarks for lutein used as a food colour, not amounts recommended to eat.

Acceptable daily intakes

EFSA allowed a wide margin for uncertainty in setting this value, because some types of long-term study were not available, and noted that at the then-current levels of use, estimated intakes at the upper end of the range exceeded it. The ADI is expressed per kilogram of body weight.

When should I talk to a doctor or pharmacist?

If you are pregnant, breastfeeding, or taking prescription medication, check with a doctor or pharmacist before taking supplements.

Dietary supplements are not intended to prevent, treat or cure any disease.