Lutein & Zeaxanthin: the carotenoids explained

Why does the retina have a yellow spot right at its centre? The answer leads straight to two plant pigments that your body cannot produce itself: lutein and zeaxanthin. This guide explains, vividly and honestly, what these carotenoids are, where they sit in the eye, which foods they are found in - and what to look for in a supplement.

Short and direct: lutein and zeaxanthin are two fat-soluble carotenoids (xanthophylls). The body cannot produce them itself - they have to come through the diet. In the eye they accumulate in the macula, forming the "macular pigment" there. Good sources are green leafy vegetables and egg yolk; in supplements they usually come from marigold flowers. Because they are fat-soluble, a little fat with the meal improves absorption.

The key points in brief

• Lutein and zeaxanthin are fat-soluble carotenoids from the group of xanthophylls.
• The body cannot produce them itself - intake only through the diet.
• In the eye they form (together with meso-zeaxanthin) the macular pigment at the centre of the retina.
• Best sources: kale, spinach, corn, yellow peppers and egg yolk; in supplements usually from marigold.
• For lutein and zeaxanthin no health claims are authorised in the EU - we describe them neutrally, without any efficacy promises.

What are carotenoids - and where do lutein and zeaxanthin fit in?

Carotenoids are a large family of plant pigments with over 700 members - they are responsible for many of the bright colours in nature, from the orange of the carrot to the yellow of corn kernels. Roughly speaking, a distinction is made between the pure hydrocarbon carotenes (such as beta-carotene) and the oxygen-containing xanthophylls. Lutein and zeaxanthin belong to the second group.

Chemically the two are astonishingly similar: the same molecular formula, differing only in the position of a single double bond. That is why they are called isomers. In nature they often occur together - one reason why they are almost always mentioned together in foods and supplements. They are absorbed in the gut together with dietary fats and then distributed via the blood.

The role in the eye: the macular pigment

The special feature: lutein and zeaxanthin accumulate in a very specific place - the macula, the area of sharpest vision on the retina. There, together with the closely related meso-zeaxanthin, they form the so-called macular pigment, which gives the centre of the retina a yellowish colouring - hence the historical name "yellow spot". Meso-zeaxanthin holds a special position here: it can be converted from lutein in the eye and hardly occurs directly in foods. We expressly describe this here as an anatomical and nutritional-science fact, without deriving any health efficacy statement from it.

Natural sources in foods

Both carotenoids can be readily taken in through a plant-focused diet. Particularly rich are green leafy vegetables as well as some yellow and orange foods:

Interesting: egg yolk does provide smaller amounts, yet is regarded as a particularly well-utilisable source - the reason is the fat matrix in which the carotenoids are embedded there. Green leafy vegetables, by contrast, provide the highest amounts per portion. Anyone who deliberately plans in kale, spinach & co. takes in lutein and zeaxanthin quite naturally. Read on: Nutrients for the eyes.

Forms and origin in supplements

In supplements, lutein is predominantly obtained from the petals of the marigold (Tagetes, Tagetes erecta) - a particularly lutein-rich plant. From the same raw material, zeaxanthin or meso-zeaxanthin can also be produced via a further step. Two basic forms are found:

• Free lutein: present in unbound form and does not first need to be split in the gut.
• Lutein esters: bound to fatty acids; first split by enzymes in the digestive tract.

Both forms are common; what matters are the declared amounts, the ratio of lutein to zeaxanthin and the quality of the raw material. The two carotenoids are often offered in a fixed quantity ratio to one another, based on their natural occurrence. On the differences between formats, see Capsule, tablet, powder or drops?.

Lutein in everyday screen life - why the topic is so present

Hardly any nutrient topic is mentioned as often in connection with long hours of screen work as lutein and zeaxanthin. The reason lies in their role as a component of the macular pigment and their property of filtering high-energy blue light - an aspect that research is investigating (see below). We expressly derive no efficacy statement from this; we merely describe why so many people who spend many hours each day in front of monitors and smartphones take an interest in these carotenoids. Anyone who fits this life situation will find further, neutral context in Nutrients for the eyes at the screen and Nutrients for office & screen.

Bioavailability: why fat makes the difference

Lutein and zeaxanthin are fat-soluble - your body absorbs them considerably better together with dietary fats. In practice this means: combine a supplement (or the green vegetables) with a little fat - a drizzle of olive oil on the salad or a handful of nuts is often enough. Interesting: lightly heating and chopping vegetables can even improve availability, because the plant cell structures are broken open. How absorption works in principle is explained in Bioavailability simply explained.

Lutein, zeaxanthin and their carotenoid relatives

Lutein and zeaxanthin are not the only carotenoids mentioned in connection with the eye and with cell protection. It is worth placing them within the larger family in order to understand products better:

• Beta-carotene is a carotene (not a xanthophyll) and a precursor of vitamin A - biochemically, then, on a different footing.
• Astaxanthin is also a xanthophyll, but usually comes from the microalga and is discussed in its own contexts - more in Astaxanthin from the microalga.
• Lycopene is the red carotenoid from tomatoes - another well-known member of the family.

This classification is purely factual: it helps you not to compare apples with oranges when comparing products, and makes clear that lutein and zeaxanthin owe their special role above all to their accumulation in the macular pigment. A broader overview of the substance group is offered by Antioxidants at a glance.

What research is investigating

The accumulation of lutein and zeaxanthin in the macula is well described and the subject of numerous studies - among the things being investigated are the question of how intake through diet affects the density of the macular pigment, and the role of the carotenoids as a filter for high-energy (blue) light. Honestly put: despite this active research, no health-related claims are authorised for lutein and zeaxanthin in the EU. We therefore describe anatomy, occurrence and the direction of research - and derive from it no effect on vision or eye health, nor do we invent figures.

What to look for in terms of quality

• Origin of the raw material: standardised marigold extracts with a stated carotenoid content.
• Amounts & ratio: clearly declared contents of lutein and zeaxanthin per daily portion.
• Format: oil- or fat-based formulations suited to fat-solubility.
• Lab testing: independent control for purity and contaminants - see Lab-tested - what does it mean?.

Since 2012, Scheunengut has stood for lab-tested products from Germany - transparency about origin and composition is standard for us. It is also worth a look at the other ingredients: a lean formulation without superfluous fillers makes sense particularly with fat-soluble carotenoids, because the actual active amounts are small anyway and the rest of the capsule is merely a carrier. How to spot unnecessary additives is explained in Recognising additives & fillers.

Honestly put

What is established: lutein and zeaxanthin are real, well-characterised carotenoids that the body does not produce itself and that demonstrably accumulate in the macular pigment - this is textbook knowledge. Not authorised as a claim is anything that would be derived from it for vision or eye health. Anyone interested in these substances covers them most naturally through green vegetables and egg yolk - supplementally, there are standardised supplements. If you have complaints or questions about your eye health, please turn to your ophthalmologist.

Matching products from Scheunengut

You will find lutein and zeaxanthin supplements in the Lutein and Zeaxanthin categories as well as under Eyes, mouth & teeth. For further reading, Nutrients for the eyes, Nutrients for the eyes at the screen, Astaxanthin from the microalga, Antioxidants at a glance and Bioavailability simply explained are a good fit. All products are made in Germany and lab-tested.

Frequently asked questions (FAQ)

What is the difference between lutein and zeaxanthin?

Both are fat-soluble carotenoids from the group of xanthophylls and chemically almost identical - they have the same molecular formula and differ only in the position of a single double bond. That is why they are called isomers. In nature they often occur together, which is why they are usually mentioned together.

Which foods contain lutein and zeaxanthin?

Particularly rich are green leafy vegetables such as kale, spinach and chard as well as broccoli and peas (above all lutein), plus corn and yellow peppers (zeaxanthin). Egg yolk provides both and, thanks to its fat matrix, is regarded as a particularly well-utilisable source.

Should you take lutein with fat?

Yes, that makes sense. Lutein and zeaxanthin are fat-soluble, so a little fat with the meal improves absorption - a drizzle of olive oil on the salad or a handful of nuts is often enough. Lightly heating and chopping vegetables can also improve availability.

What is lutein in supplements obtained from?

Usually from the petals of the marigold (Tagetes, Tagetes erecta), a particularly lutein-rich plant. From the same raw material, zeaxanthin or meso-zeaxanthin can also be produced via a further step. It is offered as free lutein or as lutein esters.