Fish, nuts and olive oil protect against eye disease

Food rich in omega-3 fatty acids, may offer protection against macular degeneration
Tue 12 May, 2009 12:00 am BST

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Regularly eating fish, nuts, olive oil and other foods rich in omega-three fatty acids, may lower the risk of age-related macular degeneration, according to research published this month's issue of Archives of Opthalmology.

Age Related Macular Degeneration - or AMD - is an eye disease of the centre of the retina. It causes the loss of central vision, leaving the person with only peripheral, or side, vision. Although it does not usually lead to total blindness, it is the most common form of sight loss in the developed world. An esitmated 500,000 people in the UK alone are affected by AMD.

Scientists in Australia investigated the relationship between diet and the occurrence of AMD in two separate studies.

In the first study, researchers from the University of Australia, monitored the diets of over 2,400 volunteers over a ten year period. Digital photographs of the retina were taken at the start of the study and also after 5 and 10 years, to check for the development of AMD.

After adjusting for age, sex and smoking, scientists found that eating one serving of fish per week had a 31 percent lower risk of developing AMD in the early stages of disease. The association was found to be strongest in those who also ate food low in linoleic acid, an unsaturated omega-6 fatty acid found in sunflower and corn oil.

Eating one to two portions of nuts a week had a 35% lower risk of early stage AMD.

The scientists said that the omega-3 fatty acids present in fish, and nuts may protect against AMD by preventing the buildup of plaque in the arteries or reducing inflammation and cell damage in the retina.

In a further study, the effects of diet on the development of early and late stages of AMD was monitored in over 6,700 Australian volunteers, aged 58 to 69.

Scientists from the Centre for Eye Research found that people who ate higher levels of trans-unsaturated fats - found in baked and processed foods - were more likely to have the later stage AMD, and people who ate the most omega-3 fatty acids as part of their diet were less likely to have early stage AMD.

Their results confirmed the previous study, as they found that people who ate the most omega-3 fatty acids as part of their diet were less likely to have early stage AMD. Dietary olive oil (greater than 100ml/week) was also associated with less late stage AMD.

The scientists concluded:
"Our findings suggest that people who follow a diet low in processed foods high in trans-unsaturated fatty acids and rich in omega-three fatty acids and olive oil might enjoy some protection from developing AMD."