Pigment that gives the vegetable its colour can slow age-related vision loss
Your parents and teachers were right – carrots really can help your eyesight.
Pigments called carotenoids – which give vegetables like carrots, peppers and spinach their colours – can slow the progression of age-related macular degeneration (AMD), researchers have found.
The condition is one of the most common causes of vision loss in older people – and is also on the rise.
A recent study published in Lancet Global Health estimated there will be 196 million sufferers by 2020 and 288 million by 2040.
The Harvard University-led study used data from a population survey that tracked more than 100,000 over-50s over a period of 25 years.
It found that those who consumed the highest levels of the carotenoids lutein and zeaxanthin had a 40 per cent lower risk of developing the advanced form of the condition than those who ate the least.
Lutein and zeaxanthin are found in high concentrations in the macula of the eye, where they are known as the macular pigment.
The macular pigment protects the macula by interacting with free radicals to prevent cell damage and by filtering out damaging blue light.
Good sources of lutein and zeaxanthin are dark leafy vegetables and eggs.
The study also found those who consumed the highest levels of some of the other forms of carotenoids – alpha-carotene, beta-carotene and beta-cryptoxanthin – had a 25 per cent to 35 per cent lower risk of advanced AMD.
Carrots and sweet potato are sources of alpha and beta-carotene, while beta-cryptoxanthin is found in fruits like oranges and peaches.
The researchers did not find any link between carotenoids and the intermediate form of AMD, however.
‘This study suggests that carotenoids may slow worsening of AMD once it occurs,’ the researchers concluded in the journal JAMA Opthalmology.
AMD, although painless, causes the loss of central vision, usually in both eyes.
According to experts at NHS Choices, the sight loss usually happens gradually over time, although it can sometimes be rapid.
With the condition, reading becomes difficult, colours appear less vibrant and people’s faces are difficult to recognise, they said.
There is currently no cure. However, AMD does not affect peripheral, or side, vision, which means it will not cause complete blindness.