Antioxidants no use against degenerative eye disease

After analysing a range of research Australian scientists say a diet rich in antioxidant vitamins and minerals does not seem to prevent the degenerative eye disease known as age related macular degeneration (AMD).

The researchers at the Centre for Eye Research Australia at Melbourne University identified 11 studies involving 149,203 people where a range of common dietary antioxidants were investigated.

All the studies were carried out amongst well nourished Western populations with an average follow-up period of nine years and all the results were adjusted for age and smoking.

AMD is the leading cause of visual loss in older people and is caused by the progressive break down of light sensitive cells in the macula which are located in the centre of the retina at the back of the eye.

Although sufferers do not go blind, they find it virtually impossible to read, drive, or do tasks requiring fine, sharp, central vision.

The risk for AMD increases with age and smokers are thought to be more susceptible.

Even though antioxidants such as vitamin C, vitamin E, various types of carotenoids, and zinc are thought to reduce oxidative damage to the retina, the evidence to support such claims remains sketchy.

For their study the researchers looked at studies on different antioxidants and found that vitamin A, vitamin C, vitamin E, zinc, lutein, zeaxanthin, á- carotene, â-carotene, â-cryptoxanthin and lycopene have little or no effect in the primary prevention of early AMD.

The authors say there is insufficient evidence to support the role of dietary antioxidants, including the use of dietary antioxidant supplements, for the primary prevention of early AMD.

They say cigarette smoking remains the only widely accepted modifiable risk factor for the primary prevention of early AMD and patients seeking advice on this condition should be encouraged to quit.

The study is published on bmj.com