A minute with... John Nolan

How long have you been studying pigments in relation to eye health?

I have spent over 15 years studying the links between nutrition and the eye, and was particularly interested in the protective role of macular pigment for patients with age-related macular degeneration (AMD).

How did science first learn there was a relationship between what we ate and what happened in the retina?

The idea is simple. People who are at risk of AMD have deficiencies in the pigments, especially meso-zeaxanthin, the central macular pigment. These pigments act as a protective layer, filtering out harmful blue light and reducing oxidative damage at the back of the eye. What we’ve discovered is how to rebuild these pigments and by doing so, we can improve vision.

We’ve also learned that three carotenoids – lutein, zeaxanthin, and meso-zeaxanthin – play a role in the brain by improving cognitive function, likely due to their antioxidant and anti-inflammatory properties. It’s very exciting in terms of what we can do with the right nutrition.

People have been taking lutein supplements for 20 years now. What is the latest advice on the carotenoids to keep retinas healthy?

When you supplement with the three carotenoids, meso-zeaxanthin, lutein and zeaxanthin in a 10:10:2 milligram ratio, you get far superior results than if you just supplement with lutein on its own. The three carotenoids work together, and it is the combination of these nutrients that gives the best results.

If we take people who are healthy and have no eye disease and give them supplements to increase their macular pigment, we can improve their visual performance. This has important implications for everyone, including pilots, military personnel and sportspeople.

We’ve just finished an AMD trial, which show these pigments greatly protect vision. I’m not saying we can stop the disease, but we have been able to rebuild macular pigment in these patients and improve their vision. The disease did not get worse after three years when patients took the supplements. This is remarkable because previous studies found with lutein-only supplements, 50% of people with early-stage AMD go on to develop advanced AMD and experience vision loss.

But with the 10:10:2 ratio, none of the trial patients went on to lose their vision. The patients are delighted with the results.

What’s your opinion of claims that there is not enough information about meso-zeaxanthin’s efficacy or safety, or that it is not necessary for eye health?

I think this view is no longer plausible. In our research we have shown meso-zeaxanthin is a very, very important part of the formula to increase macular pigment and improve vision. People who were opposed to it at the beginning simply didn’t have access to it. They wrongly said it wasn’t in nature or wasn’t in the diet, but we have now disproved that with good science.

There is very clear safety data on meso-zeaxanthin. It forms one-third of the pigment in the eye. I don’t think we humans would accumulate this pigment in the most important part of our eye if it were dangerous.

Indeed, one of our latest studies has found that many lutein supplements on the market contain very small amounts of meso-zeaxanthin – not disclosed on their product label – though not sufficient to improve macular pigment levels. Meso-zeaxanthin is extracted with the lutein taken from marigold petals. It is very difficult to obtain a pure lutein sample.

But meso-zeaxanthin is a very special molecule, and key to rebuilding the pigments to stop people losing their vision. It’s wonderful that we’ve been involved in research that will really be able to help people. It already is helping.

How long did it take for visual improvement to be seen after supplements were given to patients?

It took 12 months, but results continued to improve with sustained supplementation.

Will AMD patients need to take supplements temporarily or permanently to protect their eyes?

Permanently, but this is a small ask to help maintain vision.

Professor John Nolan, who is also a consultant for eye care supplement manufacturer MacuShield, will speak at 100% Optical on his team’s European Research Council-research into macular pigments and eye.