Clinical trials have confirmed that saffron, the famous Indian spice, can reverse age-related macular degeneration (AMD), the most common cause of blindness in the elderly. The trials were conducted in Italy and Australia.
Professor Silvia Bisti, a visiting scholar based at The VisionCentre at the University of Sydney, described the results as a breakthrough. The trial participants showed significant vision improvements after taking a saffron pill for three months, she said.
"Measurements using objective eye sight tests showed patient's vision improved after taking the saffron pill. When they were tested with traditional eye charts, a number of patients could read one or two lines smaller than before, while others reported they could read newspapers and books again."
The trial, conducted at Italy's Policlinico Gemelli by Professor Benedetto Falsini, was double blind and randomly controlled, involving 25 subjects over six months. Half the group were given a saffron pill for the first three months followed by a placebo, while the other half were given the pills in the reverse order.
"All patients experienced improvements in their vision while taking the saffron pill," Professor Bisti said. "But when they stopped taking the pill the effect quickly disappeared."
Professor Bisti began studying the effects of saffron at L'Aquila, in Italy's mountainous Abruzzi country, because it was a widely grown local crop which has been used in traditional medicine as a treatment for conditions such as cancerous tumours and depression.
"The chemistry of saffron is quite complex", she says. "It is well-known as an anti-oxidant, but no one had explored its effects on eyesight before."
Professor Bisti says "saffron appears to affect genes which regulate the fatty acid content of the cell membrane, and this makes the vision cells tougher and more resilient".
She singled out "saffron's 'anti-apoptotic' properties - its ability to increase the availability of oxygen to the body and prevent cell death," as a key factor in its beneficial effects.
In collaboration with the Catholic University of Rome and the University of L'Aquila Professor Bisti is now conducting a twelve month trial, with the aim of finding out more information about optimal doses, and at what point patients might experience a peak effect.
Another potentially fruitful line of research will be investigating saffron's ability to treat genetic diseases of the eye, such as retinitis pigmentosa, which can cause life-long blindness in young people.
Professor Bisti's work builds on many years of collaboration with Professor Jonathan Stone at the University of Sydney's The Vision Lab. The lab's extensive trials using animal models, which found that a saffron diet will protect the eye from the damaging effects of bright light, formed much of the basis for Professor Bisti's research with humans.
"After decades of lab research it is wonderful to now be able to help people," Professor Stone said.
Professor Bisti's laboratory at L'Aquila University was severely damaged in last year's earthquake in Italy and her experiments disrupted. The Vision Centre has supported two of her research staff to continue their work at the University of Sydney.