Free Radicals, Antioxidants, and the Macula
The macula is the highly specialized part of the retina used for reading, recognizing faces, and other detailed visual tasks. Rods and cones are the photoreceptors in the retina, and the macula has the highest concentration of cones of the entire retina. Cones are what give us detail and colour vision.
Think about a hand drawn picture flip movie. Each individual image is seen briefly, and then the next image is seen in a slightly different position. When each picture flips quickly one after the next, our eyes recognize a “motion picture”. Now think about how quickly your eyes must process each picture in order for you to perceive fluid motion in the actual world you live in. Your eyes “refresh” the picture much faster than the picture flip movie. Each time your eyes see and refresh the picture (about 75 to 100 times per second), your macula produces waste products. In fact, whenever the cells of your body do anything, they produce waste products. At the microscopic, cellular level, these waste products are called free radicals.
Free radicals are molecules, atoms, or ions with an unpaired electron looking for something to attach too. At a basic level, these extra electrons damage the cells in our bodies when they attach to them. This is often referred to as oxidative stress. Thankfully, our bodies have a defense against oxidative stress. Right behind the macula, there is a special layer of cells responsible for this defense. This special layer is called the Retinal Pigment Epithelium, or RPE for short. We often call these RPE cells “the garbage man cells” of the macula. They take the free radicals, package them up, and ship them out so they can’t damage the cells in the macula. That might be a simple way of thinking about the role of the RPE cells, but simple works for us. One of the most common causes of macular degeneration is the failure of the RPE to fulfill this important role.
What does all of this have to do with nutrition? RPE cells need a steady supply of antioxidant vitamins in order to do their job and package the free radicals your macula produces. If you don’t get enough antioxidant vitamins in your diet, your garbage man cells can’t do their job, the garbage will accumulate, and eventually your macula will suffer and degenerate. That’s the basic nutritional theory about how macular degeneration happens, and why it’s a good idea for all of us to have lots of antioxidants in our diet!
Antioxidant vitamins come from fruits and vegetables with a lot of colour, such as:
- Orange peppers
- Blueberries, Saskatoon berries, and red grapes
- Pumpkin, butternut squash, sweet potato, and carrots
- Brussel sprouts, broccoli, peas, green beans, and asparagus
- Mangos, kiwi, apricots, avocados
- Almonds, walnuts, cashews, sunflower and pumpkin seeds, pecans, pistachios, pine nuts and hazelnuts
Looking for more tips and fun facts about how your nutrition can result in healthy eyes? Don’t be afraid to reach out to Dr. Doig and the rest of the team at Doig Optometry at 403-333-3353. We’re always more than happy to help you see sharp and look sharp!