Waterford IT is studying whether a good diet can help reduce the risk of age- related blindness later in life, writes Dick Ahlstrom.
Maintaining a healthy diet may be one way to reduce the risk of progressive blindness in later life. Researchers at the Waterford Institute of Technology hope to show how proper eating and taking vitamin supplements might slow one of the most common forms of age-related blindness.
Age-related Macular Degeneration (AMD) affects up to 60,000 people in Ireland. It is caused by cumulative oxidative damage to the central retina, known as the macula, in the back of the eye. WIT's macular pigment research group is involved in several initiatives hoping to show how the advance of AMD can be forestalled.
The Carma Study, a North-South collaborative study between Waterford Regional Hospital, WIT, Royal Victoria Hospital and Queen's University Hospital, Belfast, forms one part of the research, says Stephen Beatty of Waterford Regional.
"It is a randomised, placebo-controlled trial of naturally occurring antioxidant supplements in an attempt to retard the progression of age related macularopathy," says Beatty, consultant ophthalmic surgeon at Wateford Regional and lecturer at WIT. "It is the first study of its kind in the world."
Funded by the charity, Fighting Blindness, Carma is assembling a cohort of 800 healthy volunteers aged between 20 and 60 years on both sides of the Border. All will be measured for their dietary intake and natural levels of key carotenoids known to protect against oxidative damage to the macula.
Oxidative damage is an inevitable by product of oxygen metabolism, and damaging free oxygen also arises by exposure to blue light, says Beatty. There is a yellow pigment at the macula composed to two carotenoids, lutein and zeaxanthin that helps protect against damage.
Both carotenoids are entirely of dietary origin and are found in yellow and orange peppers and in leafy green vegetables. Their importance is that both are powerful antioxidants and can filter out damaging blue light.
The expectation is that ensuring high dietary levels of these carotenoids will boost macular pigment levels and so help protect against AMD onset. "The possibility that the commonest cause of blindness in the world, with all of its associated suffering and socio-economic implications, could be delayed or even prevented by simple dietary modifications cannot be ignored," says Beatty.
The Carma researchers are relying on supplements rather than attempting to change the way people eat, says Beatty. "With natural sources you would have to eat a very structured diet to get these levels, and compliance would be terrible."
The supplements contain five antioxidants including vitamins C and E, zinc, lutein and zeaxanthin. "The last two are most important. Their presence in the retina was only discovered in 1993," Beatty says. "They accumulate in the macula to the exclusion of the other 50 carotenoids in your diet. There is something very specific about them."
Modern living may be contributing to the incidence of AMD and it is a disease on the rise, he says. "Age-related macular degeneration is going to become more common. It is definitely genetic and environmental," Beatty says.
"If you don't eat a healthy diet you are at greater risk of macularopathy. You can delay it by behaving yourself, by eating properly and not smoking."
Information about the work of Fighting Blindness and AMD is available at www.fightingblindness.ie
The discoverer of RNA splicing, biologist Phillip Sharp will deliver a free public lecture at O'Reilly Hall UCD tonight at 6.30pm. Prof Sharp is the recipient of UCD's inaugural Ulysses Medal. He won the 1993 Nobel Prize for his work and co-founded several biotech companies including Biogen and Alnylam.