The research was conducted at the Centre for Eye Research Australia, the University of Melbourne, where the researchers analysed the evidence to examine the role of dietary antioxidants or dietary antioxidant supplements in the primary prevention of age related macular degeneration.
The findings are reported on bmj.com.
The authors looked at 11 studies (seven prospective studies and three randomised controlled trials) involving 1,49,203 people. A range of common dietary antioxidants was investigated and all the studies were carried out amongst well-nourished Western populations with an average follow-up period of nine years. Most importantly, all the studies adjusted for age and smoking in their analyses.
When the results were pooled, they showed that vitamin A, vitamin C, vitamin E, zinc, lutein, zeaxanthin, a- carotene, Ŗ-carotene, Ŗ-cryptoxanthin and lycopene have little or no effect in the primary prevention of early age-related macular degeneration.
The study showed that none of the three trials found antioxidant supplements to be protective in the primary prevention of early age related macular degeneration.
This disease is the leading cause of visual loss in older people. It is caused by the progressive break down of light sensitive cells in the macula, located in the centre of the retina at the back of the eye. People suffering from the disease do not go blind, but find it virtually impossible to read, drive, or do tasks requiring fine, sharp, central vision. Risk of the disease increases with age and smokers are thought to be more vulnerable.
Antioxidants were considered to reduce oxidative damage to the retina. But the evidence to support the role of dietary antioxidants in preventing macular degeneration remained unclear, therefore researchers carried out this study.
And after the study, the authors concluded that there is insufficient evidence to support the role of dietary antioxidants, including the use of dietary antioxidant supplements, for the primary prevention of early age-related macular degeneration.
The researchers have also added that presently, smoking remains the only widely accepted modifiable risk factor for the primary prevention of early age-related macular degeneration, and patients seeking advice on this condition should be encouraged to quit.