Antioxidants do not prevent degenerative eye disease

Oct 09, 2007

A diet rich in antioxidant vitamins and minerals does not seem to prevent the degenerative eye disease known as age related macular degeneration, finds a study published on bmj.com today.

Age related macular degeneration 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. Sufferers do not go blind, but find it virtually impossible to read, drive, or do tasks requiring fine, sharp, central vision.

Risk increases with age and smokers are thought to be more susceptible.

Antioxidants (such as vitamin C, vitamin E, various types of carotenoids, and zinc) are thought to reduce oxidative damage to the retina. But the evidence to support the role of dietary antioxidants in preventing macular degeneration remains unclear.

So researchers at the Centre for Eye Research Australia, the University of Melbourne analysed the evidence to examine the role of dietary antioxidants or dietary supplements in the primary prevention of age related macular degeneration.

They identified 11 studies (seven prospective studies and three randomised controlled trials) involving 149,203 people. A range of common dietary antioxidants were investigated and all the studies were carried out amongst well nourished Western populations with an average follow-up period of nine years.

Importantly, all the studies adjusted for age and smoking in their analyses.

The antioxidants investigated differed across studies, but when results were pooled they showed that vitamin A, vitamin C, vitamin E, zinc, lutein, zeaxanthin, α- carotene, β-carotene, β-cryptoxanthin and lycopene have little or no effect in the primary prevention of early age-related macular degeneration.

None of the three trials found antioxidant supplements to be protective in the primary prevention of early age related macular degeneration.

Despite some study limitations, the authors conclude 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.

Currently, cigarette 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, they add.

An accompanying editorial by Jennifer Evans at the International Centre for Eye Health supports these findings and says that reducing the prevalence of smoking is probably the most effective method of reducing the population burden of this common cause of visual loss in older people.

Source: British Medical Journal

Explore further: Why alcoholism saps muscle strength

add to favorites email to friend print save as pdf

Related Stories

Breeding better broccoli

Nov 04, 2009

Carotenoids—fat-soluble plant compounds found in some vegetables—are essential to the human diet and reportedly offer important health benefits to consumers. Plant carotenoids are the most important source of vitamin ...

Diet could reduce onset of eye disease by 20 percent

Feb 18, 2009

University of Liverpool scientists claim that the degeneration of sight, caused by a common eye disease, could be reduced by up to 20% by increasing the amount of fruit, vegetables and nuts in the diet.

Should Anyone Still Take Vitamin E?

Dec 18, 2008

Researchers at UC Berkeley discovered vitamin E in 1922, and since then countless studies have been done on this still mysterious substance. Because its chief function seems to be as an antioxidant, neutralizing potentially ...

Recommended for you

Why alcoholism saps muscle strength

1 hour ago

Muscle weakness is a common symptom of both long-time alcoholics and patients with mitochondrial disease. Now researchers have found a common link: mitochondria that are unable to self-repair. The results will be published ...

Scientists make critical end-stage liver discovery

3 hours ago

(Medical Xpress)—A team of researchers in the University of Arizona's College of Pharmacy has discovered a molecular pathway that could be key to creating new therapeutics that would slow or even reverse ...

Leeches help save woman's ear after pit bull mauling

Apr 18, 2014

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

User comments : 0

More news stories

Teachers' scare tactics may lead to lower exam scores

As the school year winds down and final exams loom, teachers may want to avoid reminding students of the bad consequences of failing a test because doing so could lead to lower scores, according to new research published ...