Clearer Journal · Eye NUTRITION
By Clearer Research
14 July 2026 · 5 min read
Lutein and zeaxanthin are carotenoid pigments, and they are abundant in marigold flowers.
01 · THE SCIENCE OF LUTEIN AND ZEAXANTHIN
The marigold is usually grown for its colour. But the same pigments that give its petals their deep yellow-orange tone have made one species of the flower important to nutrition science.
The petals of Tagetes erecta, which is sometimes called Aztec or African marigold, are a concentrated and highly bioavailable source of lutein and smaller amounts of zeaxanthin. These yellow-orange compounds belong to the carotenoid family. Once consumed, they do something unusually selective: they accumulate in particular tissues, including the macula at the centre of the retina.
That journey, from the flower to the eye, is well established. Researchers are also investigating what lutein and zeaxanthin may do elsewhere, including the brain and skin.
Marigold flowers are the most commonly used source of lutein and zeaxanthin in supplements.
02 · Carotenoids and the macula
At the centre of the retina lies the macula, the small region responsible for detailed central vision. Within it, lutein, zeaxanthin and meso-zeaxanthin form the macular pigment. Its yellow colour is not incidental: these pigments absorb part of the blue-violet light entering the eye before it reaches the light-sensitive photoreceptors beneath them.
They may also help manage oxidative stress. The retina consumes substantial oxygen, contains oxidation-prone fatty acids and is exposed to light throughout waking life. Lutein and zeaxanthin can interact with reactive oxygen species in laboratory systems, giving researchers a plausible second reason, in addition to optical filtration, to study them in retinal health.
Human trials show that supplementation can increase macular pigment optical density, a measure of how much macular pigment is present. Some trials in healthy adults have also reported improvements in visual measures such as photostress recovery and contrast. The best-known clinical programme is AREDS2, which studied 4,203 people at high risk of progression to late age-related macular degeneration (AMD). At ten years, assignment to lutein and zeaxanthin, in a composite antioxidant supplement formulation, was associated with a modestly lower risk of progression to late AMD than no lutein and zeaxanthin.
Lutein and zeaxanthin are present in large amounts in the macula and help to filter blue light.
03 · Cognitive benefits
Not Only the Eye, But Also the Brain
The retina is neural tissue, so it is perhaps unsurprising that lutein and zeaxanthin can cross the blood-brain barrier and are also found in the brain. This has prompted research into whether their antioxidant, anti-inflammatory and structural roles might influence cognition.
Several small randomised trials are encouraging. In a one-year study of 51 older adults, 10 mg of lutein plus 2 mg of zeaxanthin increased macular pigment and improved scores for complex attention and cognitive flexibility compared with placebo. A six-month trial involving 90 adults with self-reported cognitive concerns found improvements in visual episodic memory and visual learning, but not across the study’s other cognitive or self-reported measures.
There is also important counterevidence. A much larger AREDS2 cognitive study found no statistically significant effect of lutein and zeaxanthin on cognitive decline over five years in older adults with AMD. Differences in participant health, baseline nutrition, test sensitivity and study design may help explain the discrepancy.
The balanced conclusion is that lutein and zeaxanthin are present in neural tissue and may influence selected aspects of cognition.
04 · Carotenoids and BEAUTY
Carotenoids also reach the skin, where they form part of its network of antioxidant compounds. This has led researchers to examine whether lutein and zeaxanthin can affect the skin’s response to environmental stress.
In one double-blind, placebo-controlled study, oral and topical lutein and zeaxanthin were tested against measures including hydration, elasticity, surface lipids, lipid oxidation and photoprotective activity. The largest changes were seen when oral and topical treatments were combined.
A later 12-week trial in 46 healthy adults with mild-to-moderate dry skin tested 10 mg of lutein with 2 mg of zeaxanthin isomers. Compared with placebo, the supplement increased the minimal erythema dose, the amount of ultraviolet exposure required to produce visible redness, and improved some measurements of skin tone.
Lutein and zeaxanthin are not substitutes for sunscreen, shade, or protective clothing, but they might help to strengthen your skin's natural defence.
Small human trials have examined lutein and zeaxanthin in relation to skin response and appearance.
05 · one flower, three areas of research
Marigold’s real scientific interest is more specific and more compelling than the idea of a botanical cure-all. Tagetes erecta provides concentrated lutein and zeaxanthin: dietary pigments that the body selectively places in the macula, which researchers can also measure in the eye, brain and skin.
The body cannot synthesize lutein and zeaxanthin, so they must be obtained from the diet. The typical Western diet provides only 1-2mg of lutein and zeaxanthin per day, well below the dosages used in lutein and zeaxanthin studies.
You might ask: why should I get lutein and zeaxanthin from marigold flower instead of regular dietary sources?
The issues are bioavailability and dosage. Lutein and zeaxanthin are naturally present in leafy greens like kale and spinach (lutein) and orange peppers, sweetcorn, goji berries and egg yolk (zeaxanthin). However, vegetable sources are poorly absorbed unless cooked and eaten with fat, and egg yolk, while highly bioavailable, contains only 0.2-0.3bmg per yolk.
By contrast, marigold is highly concentrated and bioavailable. Taking lutein and zeaxanthin from a supplement helps to ensure that you are supporting your eyes with the nutrients they need, and they might help other parts of your body too.
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While many eye health supplements contain lutein and zeaxanthin for macular support, Clearer® combines other research-backed antioxidants that target different parts of the eye to provide all-round support.
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