A compound found in oranges could help protect against an incurable age-related eye disease, according to new research.

A study has shown that people who regularly eat oranges are less likely to develop macular degeneration – which affects around 2.4% of the adult population in the UK – than people who do not eat the citrus fruit.

The researchers at the Westmead Institute for Medical Research in Australia say that flavonoids – a group of nutrient-rich plant compounds found in oranges and other fruit and vegetables – have been linked to a decreased likelihood of developing the eye disease.

The research is based on 2,000 adults aged over 50 over a 15-year period.

Age-related macular degeneration (AMD) is a common condition that affects the middle part of vision among those in their fifties and sixties.

While it does not cause total blindness, AMD can make everyday activities such as reading and recognising faces difficult.

The results showed that people who ate at least one serving of oranges every day had “more than a 60% reduced risk of developing late macular degeneration 15 years later”, the scientists said.

Bamini Gopinath, an associate professor from the University of Sydney and lead study author, added: “Even eating an orange once a week seems to offer significant benefits.

“The data shows that flavonoids found in oranges appear to help protect against the disease.”

Dr Gopinath said that until now most research has focused on the effects of common nutrients such as vitamins C, E and A on the eyes.

She added: “Our research is different because we focused on the relationship between flavonoids and macular degeneration.

“Flavonoids are powerful antioxidants found in almost all fruits and vegetables, and they have important anti-inflammatory benefits for the immune system.

“We examined common foods that contain flavonoids such as tea, apples, red wine and oranges.

“Significantly, the data did not show a relationship between other food sources protecting the eyes against the disease.”

The team wrote in their paper: “Our findings suggest an independent and protective association between dietary intake of flavonoids and the likelihood of having AMD.”

They added that additional studies are needed to validate their findings.

The research is published in the American Journal of Clinical Nutrition.