Switching to a Mediterranean-type diet can slash your risk of developing an incurable but common eye disease by as much as a third, a study of 6,000 people has found.

The research was conducted by a group of 20 leading specialists at one of Europe’s oldest and most esteemed universities, Portugal’s Coimbra University.

The disease is macular degeneration — a leading cause of blindness — and the study was led by Dr. Rufino Silva, who heads the medical faculty’s ophthalmology department.

“We found those who closely followed the Mediterranean diet had a 35 percent lower risk compared to those who did not adhere to the diet,” tells Newsmax Health.

“This effect was mainly driven by increased fruit consumption.”

The American National Eye Institute has long advised people to eat a healthy diet rich in green, leafy vegetables, and fish.

Similar advice comes from two of the nation’s leading organizations involved in educating people about macular degeneration — the Macular Degeneration Foundation and the similarly-named American Macular Degeneration Foundation.

Chip Goehring, president of the American Macular Degeneration Foundation, notes that the eye condition is little-known even though it’s the leading cause of blindness in people older than 55.

As he puts it: “Macular degeneration remains something of a mystery.”

It mainly afflicts the middle-aged and elderly, who tend to be more familiar with other eye diseases such as cataracts and glaucoma.

Nonetheless, Goehring’s foundation estimates macular degeneration affects about 10 million Americans.

A macular degeneration sufferer himself, who sought medical advice when his eyesight deteriorated, Goehring knows “the shock of being told I might go blind from a disease I’d never heard of.”

Prominent American nutritionist Joy Bauer notes foods high in vitamins C and E as well as those rich in beta-carotene — mostly fruits and vegetables — have been scientifically proven to lower the risk of developing macular degeneration.

Britain’s Royal National Institute of Blind People also warns that “smoking greatly increases the risk of developing age-related macular degeneration.”

Dr. Joao Figueira, a Coimbra University ophthalmology professor and a senior member of Silva’s team, tells Newsmax Health the study involved two groups of people (of both sexes; all age 45 or older) from the Portuguese towns of towns of Lousa (population nearly 18,000) and Mira (population about 12,500).

Why two towns?

Figueira explains: “Lousa is inland and Mira is coastal. There are slight dietary differences — the coastal people eat more fish and other seafood, for instance — so we needed to be sure any differences in risk factors were apparent. However, there were no significant risk differences.”

The Mediterranean diet generally involves lots of fruit, vegetables, olive oil, and red wine along with moderate consumption of protein and low consumption of red meat. This diet is widely believed to confer health benefits to the heart and brain.

Figueira said the good news is that most people needn’t follow a strict Mediterranean diet — “just broadly. We found people in the study didn’t all eat exactly the same thing. Small differences didn’t matter. We found fruit consumption particularly important.”

And one surprising finding of the new research should please java junkies: “Coffee isn’t usually considered part of a Mediterranean diet but Portugal is a coffee-drinking country. We found caffeine is good — and one of the things we’re looking at in follow-up research is what particular component of caffeine offers protection.”

Silva says the research was presented at a recent conference of the American Academy of Ophthalmology and various other national conferences. A journal paper will appear soon, after peer review.

Silva adds that his research is just “one more reason to keep eating healthily.”