Researchers have found that a substance found in grapes and other fruits could protect blood vessels in the eye being damaged by old age.

It is effective because the compound, known as resveratrol, stops the blood vessels from being damaged.

The substance, which has been linked to anti-ageing and cancer protection in the past, is believed to work because it protects against abnormal angiogenesis - the formation of damaged or mutated blood vessels.

This condition is linked to cancer, heart disease and eye diseases such as age-related macular degeneration.

Dr Rajendra Apte, who carried out the research at Washington University School of Medicine, St Louis, said the study should have a "substantial impact" on our understanding of how resveratrol works.

He said it was able to "demonstrate that resveratrol, a naturally occurring compound, can directly inhibit the development of abnormal blood vessels both within and outside the eye".

This he said could lead to new treatments.

Resveratrol is a natural compound that is produced in a variety of plants to prevent bacterial and fungal infections.

It is found in particularly high levels in grape skin (and consequently red wine), and at lower levels in blueberries, peanuts, and other plants.

Various studies have shown that resveratrol can decrease the effects of ageing and act as an anti-cancer agent.

Red wine has also received a lot of attention lately for its purported health benefits.

Along with reducing stroke, moderate wine consumption has been linked to a lowered incidence of cardiovascular disease - the so-called French paradox.

Despite diets high in butter, cheese and other saturated fats, the French have a relatively low incidence of cardiovascular disease, which some have attributed to the regular drinking of red wine.

This study published in The American Journal of Pathology shows why this works.