While some studies examining eye health and nutrition are inconclusive, there are some prominent studies (including the Age-Related Eye Disease Study (AREDS), Rotterdam, the Blue Mountains Eye Study (BMES), and prospective analysis from the Nurse’s Health Study and the Health Professional Follow-up Study) which show the benefit of good nutrition.
The common recommendation between most of these studies is the emphasis on adequate intake of fruit and vegetables. These are the source of important micro-nutrients. The eye is susceptible to oxidative damage (high metabolic rate and light- exposure) which means antioxidants are important for the oxidative stress- related eye diseases including cataracts, glaucoma, and macular degeneration (MD).
Current evidence shows everyone with MD, regardless of whether the changes are early/mild or advanced, should be advised to eat more dark green leafy vegetables and fish, and to consume low glycemic index (GI) diets.
The Age-Related Eye Disease Study (AREDS) demonstrated that taking a supplement containing high doses of vitamin C, vitamin E, beta-carotene, zinc, and copper could reduce MD progression by 25% - worth considering.
The follow up study (AREDS 2), found adding lutein and zeaxanthin (naturally occurring carotenoids) or omega-3 fatty acids to the original formula had no overall effect on the risk of advancing MD. But the trial found that swapping beta-carotene with a five to one mixture of lutein and zeaxanthin could help to further reduce late MD risk.
Associate Professor Bamini Gopinath, an epidemiologist with the Univeristy of Sydney aims to move the research forward. She is using the landmark BMES to investigate links between dietary habits and risk of MD. For instance, the epidemiological data available on the association between vitamin B12 and folate with MD is largely equivocal. Data has shown that people with vitamin B12 deficiency had around 58% higher risk of developing early MD, and just over two-fold increased risk of late AMD over a 10-year follow up. Similarly, folate deficiency was associated with 75% and 89% increased risk of early and late MD respectively.
Conversely, participants who were taking vitamin B12 supplements had 47% per cent reduced risk of developing any MD 10 years later. These associations were independent of factors such as smoking, fish consumption and antioxidant intake.
It has been proposed that the direct antioxidant effect of vitamin B12 and folate could explain this beneficial influence on MD risk. There is not enough evidence to recommend B12 and folate supplementation to prevent the development of MD.
As this work continues we will no doubt hear more evidence for the benefits of micro and macro nutrients. The take-home message is still about diet and at this time of year look no further than brussel sprouts!
Here are a couple of recipes to inspire.