Eating a healthy diet may protect your vision. A new study shows a high intake of omega-3 fatty acids and a low glycemic index reduces the risk of age-related macular degeneration.

 Summary

Omega-3 fatty acids and a diet that has a low glycemic index are found to be protective against age-related macular degeneration. That is the main finding of a new, eight year study.

Introduction

Age-related macular degeneration (AMD) is a leading cause of vision loss among older people, leading to loss of independence and quality of life. It is characterized by patchy vision, caused by degeneration of the light-sensitive retina at the back of the eye. There are, as yet, few effective treatments for the disease, so any advances in prevention are important.

What was done

Researchers at Tufts University and the University of Wisconsin carried out the Age-Related Eye Disease Study (AREDS) to see whether vitamin and mineral supplements can protect against AMD. A group of nearly 3,000 people at risk of AMD were given either zinc, antioxidants, zinc plus antioxidants or placebo and their eye health examined over ten years. Dietary information was also collected at the start of the study. The researchers related the risk of AMD progression to dietary intake, as well as analyzing the impact of the supplements.

What was found

Independent of supplementation, higher intakes of DHA (docosahexaenoic acid, an omega-3 fatty acid) were related to lower risk of progression of AMD. A similar association was found with intakes of the other important omega-3 fatty acid, EPA (eicosapentaenoic acid). A further link was found between a diet with a low glycemic index (GI) and protection from AMD progression.

What this study means

The role of supplements in protecting vision is not yet clear. However, a diet rich in omega-3 fatty acids does appear to be protective. Eating oily fish a couple of times a week should achieve this goal – and is healthy for other reasons too. The finding of the link between a low GI diet and protection from AMD progression is interesting. Low GI foods are those that release sugar into the bloodstream more slowly than high GI foods. Examples of the former include complex carbohydrates such as whole grain cereals and many (but not all) fruits and vegetables. Processed foods and sugary drinks tend to be high GI. A healthy diet rich in fruit, fish, vegetables, whole grains and low in simple sugars is known to have many health benefits and, to this, we can now add eye health.

Source

Chiu CJ, Klein R et al Does eating particular diets alter the risk of age-related macular degeneration in users of the age-related eye disease study supplements? British Journal of Ophthalmology Online First June 9 2009; 136/bjo.2008.143412