As some of you are aware, I work as a Clinic Assistant for a glaucoma clinic. So from Monday to Friday I'm looking at and talking about eyes. I thought it might be interesting to explore how nutrition can affect certain eye conditions. Sadly, I can't talk about glaucoma because it's predominantly a hereditary condition, but I would like talk about a condition known as Age- Related Macular Degeneration (AMD). The burning question is what is AMD? AMD is a condition where the central part of the retina (macula) becomes damaged and central vision is gradually lost. As the name suggest this conditions tend to affect those who are aged 60 years and above. I know everyone reading this article is not in this age group but nutrition and lifestyle can play a significant role in the development of this condition later on in life. Throughout the course of this article, I intend to discuss how optimum and poor nutrition combined with lifestyle factors can both potentially influence the development of AMD.
Risk factors
Similar to most cardiovascular and metabolic conditions, smoking is one of the greatest risk factors for AMD. It has also been defined as one of the modifiable risks factors. How does smoking cause AMD? As most of you know cigarette contains tobacco and when released into the bloodstream it stimulates the release of harmful substances known as Reactive Oxygen Species (ROS). An imbalance between the production of ROS and antioxidant defences, is known as oxidative stress. How does this effect the retina? The oxidative stress causes our DNA to become damaged and as a 'knock - on - effect' this causes the automatic death of the retinal cell. Consequently, the light can't be signalled to the brain and central vision is lost.
Inadequate Nutrition
What about poor nutrition does that play a role in the development of AMD? To date there is limited evidence to suggest that a diet high in cholesterol and saturated fat is linked to the development of AMD. However, studies have suggested that foods high in sugar causes the build-up of extra cellular yellow material known as drusen, which are clinical indicators of early AMD. Furthermore, a reduced intake of foods containing anti-oxidants can increase the likelihood of AMD progression.
Maintaining Optimum Nutrition
So how does nutrition manage and/or prevent AMD? Various studies have shown that consuming foods that are rich in antioxidants and fish oils help reduce the build-up of ROS and 'Free radicals'. Let's start with discussing the different types of anti-oxidants and their mechanism of action. Vitamin C has been found to protect the body from ROS and free radicals, acquired through metabolic processes and through toxins and cigarette smoke. Vitamin E provides protects the cells which line the retina and is responsible for neutralising free radicals. Similar to Vitamin E, Zinc molecules play an essential role in maintaining structure and functioning of the cells which line the retina. Studies have proven that a decreased amount of zinc makes these cells susceptible to oxidative damage, which is the primary cause of AMD. Unlike Vitamin E and Zinc, Lutein and Zexanthin have a more specific antioxidant role. They protect the macula (area of the retina that controls central vision), by 'absorbing blue light/and or quenching reactive oxygen species'.
Recommendations
I know a lot of you have been eagerly awaiting this section. As previously discussed, the management and prevention of AMD can be achieved by making both dietary and lifestyle modification. These should include:
-Reduce or avoid smoking
-Try to incorporate oily fish as part of your diet, the essential fatty acid DHA helps reduce the risk of oxidative stress in the retina. These includes foods such as trout, crab, haddock, mackerel, salmon, shrimp and sardines.
-Eat wide variety of fruit and vegetables, such as oranges, blackberries, cauliflower, Brussels sprouts, spinach, kale, sweet potatoes, apricots and squash. These foods are rich in many antioxidants such as vitamin C, E, and betacarotenes.
-Eat foods rich in zinc, these include Spinach, Seafood, Pumpkin and Squash Seeds.
-Take part in physical activity for at least 150 minutes a week, this will help maintain good circulation and prevent high pressures (ocular hypertension) in your eyes.
