Parents may have told their kids: "Eat your carrots, they're good for your eyes," and a new study suggests that they were right.
Pigments called carotenoids, which give vegetables their colors, can slow the progression of age-related macular degeneration (AMD), researchers claim.
Age-related macular degeneration is one of the most common causes of vision loss, especially in the elderly. It affects the macula, the center part of the retina, and can lead to declines in sharp central vision and even blindness, experts say.
The Harvard University-led study used data from a survey that tracked more than 100,000 over-50s for 25 years.
It found that those who consumed the highest levels of the carotenoids lutein and zeaxanthin had a 40 percent lower risk of developing the advanced form of the condition than those who ingested the least.
The study also found that 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 good sources of alpha and beta-carotene, while beta-cryptoxanthin is found in oranges and peaches.
Researchers did not find any link between the carotenoids and the intermediate form of macular degeneration, however.
"This study suggests that carotenoids may slow worsening of AMD once it occurs," the researchers concluded in the journal JAMA Opthalmology.
Lutein is found in eggs and dark leafy vegetables including broccoli, kale and spinach, Bernstein said. Zeaxanthin is harder to find in the diet, he said, but you can get it from corn, orange peppers and goji berries.
Researchers cautioned that the study has some weaknesses. It's based on people's recollections of their diets and doesn't examine the levels of the carotenoids that actually made it into their bodies and eyes.
Carotenoid supplements is recommended to people with intermediate and advanced forms of macular degeneration, but it's not proven if they'll help people who may be at risk for the condition.
However, a diet high in fruits and vegetables is important, especially colorful vegetables. It is advised to consume several servings a day.
