Preventing Age-related Macular Degeneration
Age-related Macular Degeneration (AMD) is the leading cause of blindness in the developed world. Almost six million Americans have some vision loss from AMD, with 200,000 new cases diagnosed each year. AMD is beginning to be discussed in the same breath as the word “epidemic.” My own mother, at 88, has AMD, but she doesn’t really understand it–or know what she might be able to do to slow the progression. This post is for her–and all of us who want to preserve our sight as long as possible.
So what is AMD?
In AMD, the protective layer of cells at the very back of the eye is damaged. This one-minute video explains:
Animation of Wet and Dry Macular Degeneration
The damage to the retina leaves a blurry or dark ‘hole’ right in the center of the image being viewed, while leaving the periphery still visible. This particular kind of vision loss is tremendously frustrating since human expression is such a vital form of communication, particularly for those experiencing dementia. Whatever the senior focuses on ends up being the very thing they can’t see. For those with advanced dementias, like Alzheimer’s, a resident may seem to be looking at their meal–but be unable to see the food at the end of the fork, and at the same time be unable to communicate their difficulty.
What causes it?
The cells at the back of the eye deteriorate over time simply through the aging process itself. But certain factors have been identified as directly increasing the risk of AMD: genetic status, smoking, cumulative exposure to visible light rays, and poor diet, among other things. Let’s look at two risk factors that we might be able to do something about: blue light exposure and diet.
Blue Light is part of the visible light spectrum; it helps us wake as it gets lighter in the morning by sending a signal to the brain to stop producing melatonin, a hormone that helps regulate the wake/sleep cycle. As it gets darker at night, the loss of blue light should trigger the production of melatonin again, to aid in sleep. But wait—what about all those blue-light-producing electronics our eyes are glued to all day and much of the evening? Well, at the very least, all that blue light exposure isn’t helping our sleep cycle, and at worst, blue rays may contribute to retinal damage and possibly lead to AMD particularly in those at risk. According to the American Macular Degeneration Foundation, the type of damage depends on wavelength, power level and exposure time. Ask your eye doctor or eye care professional about protection if you are at risk. UV/blue spectrum protection is available as a coating for clear lenses as well as sunglasses–and it doesn’t change the color of the lens.
Poor diet leaves the macula–that area right by the optic nerve–less able to protect itself from cell damage caused by other risk factors. There are potent carotenoids, or compounds, located in the pigment there, protecting cells from blue light and functioning as antioxidants. Scientists believe that the two primary carotenoids–lutein and zeaxanthin–are essential for eye health and for protection from AMD. Lutein and zeaxanthin come from the food we eat: colorful fruits and vegetables in the red, yellow and orange spectrum, like peaches, carrots, corn and squash. Lutein is also found in dark green leafy veggies, like spinach and kale.
One of the best sources of both compounds is found in egg yolk. The concentration is a bit less, but the bioavailability–the ability of the body to absorb the nutrient–is very high. This is likely due to the fat in the yolk, since these nutrients are fat-soluble, which means they ‘upload’ into the body best in the presence of fat. The humble egg provides the prefect ‘delivery’ vehicle for these essential compounds, as well as being one of the few known sources for a third compound, meso-zeaxanthin, which scientists think also plays a vital role in protection from AMD. (Unfortunately there is an entire generation out there–including my own 88 year-old mom–who were led to believe that the yolk was bad for them. For years I have encouraged my mom to eat an egg for breakfast, only to hear her respond that she did, indeed, eat an egg–but only the white part. The false idea that the cholesterol in eggs is bad for us persists today, as evidenced in McDonald’s silly decision to promote egg-white only breakfast sandwiches. Today my mom suffers from AMD in both eyes, and can no longer see to drive or read. And I still can’t get her to eat the yolks.)
Dr. John Nolan is the lead researcher at the Macular Pigment Research Group, at the Waterford Institute of Technology in Waterford, Ireland. The group’s mission is to study the role of nutrition for optimizing visual function and prevention of blindness, cognitive function and prevention of Alzheimer’s disease. According to Dr. Nolan, the research that has been done over the last 15 years has shown that enriching the pigment levels of these vital carotenoids in the macula “can enhance visual function in a very real way.” So, while a poor diet can potentially leave your vision at risk, making sure we eat well, and taking appropriate supplements if we are deficient, can effectively lower our risk for AMD…which, we can all clearly see, is good news, indeed!
Learn more about the research being conducted on nutrition and AMD at: Macular Pigment Research Group
(Images of AMD obscuring view of boy from: http://lickteigfamilyeyecare.net/macular-degeneration/)