New research has shown that a diet high in beta carotene, vitamins C and E, and zinc is associated with a substantially reduced risk of age-related macular degeneration in elderly people.
Age-related macular degeneration or AMD, is the most common cause of irreversible blindness in elderly in the developed world.
It is a degenerative disorder of the macula, the central part of the retina.
In its' late-stage AMD sufferers are unable to read, recognize faces, drive, or move freely.
The disease becomes more common with aging and apparently affects 11.5 percent of whites over age 80.
At present there is little effective treatment for AMD, and the number of patients severely disabled by late-stage AMD is expected to rise in the next 20 years by more than 50 percent as much as 3 million in the United States.
To date studies evaluating both dietary intake and serum levels of antioxidant vitamins and AMD have provided little conclusive proof that supplements can slow the progression of the disease.
In this study Redmer van Leeuwen, M.D., Ph.D., of Erasmus Medical Centre, Rotterdam, the Netherlands, and colleagues investigated whether antioxidants, such as is present in normal daily food intake, play a role in the prevention of AMD.
The Rotterdam Study included inhabitants aged 55 years or older from a middle-class suburb of Rotterdam, in the Netherlands.
Of the 5,836 persons at risk of AMD at the outset, 4,765 provided reliable dietary information and 4,170 participated in the follow-up.
Dietary intake was assessed initially using a food frequency questionnaire, and the follow-up continued until 2004.
On average each participant was monitored for 8 years.
It was revealed during this period that 560 persons (13.4 percent) were diagnosed as having new AMD, the majority of whom had early-stage AMD, but that risk was modified by diet, in particular, where vitamin E and zinc was achieved by consumption of whole grains, vegetable oil, eggs, and nuts, meat, poultry, fish and dairy products.
On the basis of this study, foods high in these nutrients appear to be more important than nutritional supplements.
Good sources of beta carotene are carrots, kale, and spinach, while vitamin C is found in citrus fruits and juices, green peppers, broccoli, and potatoes.
The researchers say that until more research is available, the information may be useful to persons with signs of early AMD or to those with a strong family history of AMD.
They say that although their findings need confirmation, their observational data suggests that a high intake of specific antioxidants from a regular diet may delay the development of AMD.
The study is published in the December 28 issue of JAMA.