Carotenoids are plant-based pigments responsible for much of the colour that surrounds us. Over 700 types exist in nature, giving colour to plants, fish skin, and bird feathers.
In the past, carotenoids have been used for their colour in both the food and textile industries. However, it wasn’t until our research that we discovered the important role that carotenoids, as nutrients, can play in human eye and brain health.
A typical Western diet contains around 50 carotenoids, but only about 20 reach the bloodstream. As humans, we cannot produce carotenoids ourselves, we must consume them through foods such as leafy greens, corn, and eggs.
Of all the carotenoids, just three are found in the eye and brain: lutein, zeaxanthin, and meso-zeaxanthin. Meso-zeaxanthin is especially important for eye health, yet our intake is very limited. To compensate, the body converts lutein into meso-zeaxanthin, but my research has shown that 12% of people cannot do this and therefore must be provided this carotenoid directly from a supplement.
To understand carotenoids, it helps to first understand how vision works. The eye acts like a smart camera: light enters through the lens and is focused onto the retina at the back. At the very centre is the macula, a tiny but powerful region that gives us sharp, detailed vision for everyday tasks like reading, driving, and recognising faces.
The macula is protected by a yellow pigment layer known as the macular pigment, made up of the three macular carotenoids, lutein, zeaxanthin, and meso-zeaxanthin. These nutrients act like natural sunglasses, absorbing harmful blue light and protecting delicate cells from oxidative stress.
Our research has shown that enriching macular pigment can:
We’ve also demonstrated that DHA plays an important role in supporting the retina’s structure and function, making it a key nutrient for long-term eye and brain health.
Lutein and zeaxanthin gather to form the protective macular pigment at the back of the eye, with Meso-zeaxanthin forming the epicentre of yellow pigment layer/spot. It acts like sunscreen for our eyes protecting them from blue light and a process known as oxidative stress which damages sensitive tissue/cells surrounding the retina. Our research has shown that people with low levels of meso-zeaxanthin are at a higher risk of having or developing macular degeneration.
Meso-zeaxanthin is rarely found in our diet, so the only way to reliably increase or replenish our supply of meso-zeaxanthin is to take a supplement that contains it. Through our research, we have identified the marigold flowers of Puebla, Mexico as a source of this vital carotenoid. Taken as a supplement, meso-zeaxanthin can rebuild macular pigment and protect and enhance your vision.
The eye and brain are deeply connected; what benefits one, often supports the other. Carotenoids are not only important for our eyes, but also for the brain. Just like in the macula, lutein, zeaxanthin and meso-zeaxanthin accumulate in areas of the brain that are central to memory, learning, and processing speed. These nutrients support communication between brain cells and protect our brain tissue from oxidative stress.
Our research at the NRCI has shown that people with higher levels of these macular carotenoids in the brain perform better on measures of cognitive function, including memory and attention. In ageing populations, maintaining healthy levels of these nutrients has been linked to slower cognitive decline. By protecting brain tissue and supporting efficient signalling, carotenoids can play a key role in maintaining brain health across the lifespan. You can learn more about this by reading our re-MIND clinical trial paper here.
My goal in sharing this research with you is to empower you to take a proactive role in protecting your vision and brain health. The evidence shows that targeted supplementation, when combined with positive lifestyle choices such as balanced nutrition and regular exercise, can help maintain and safeguard these vital functions at every stage of life.
The key is to act early. Don’t wait until the eyes or brain begin to decline—integrating these scientifically backed strategies into your daily routine now offers the best opportunity to preserve long-term health and quality of life.
