CrossFit Masters Nutrition and Vision. Our vision changes with age. Much of that change may be due to exposure to ultra-violet light (uv-radiation). Ultra-violet light is the same range of light that causes sunburns. Eyes are naturally protected from ultra-violet light by anti-oxidants.
There are three anti-oxidants that protect the eye. These are lutein, zeaxanthin, and meso-zeaxanthin. Lutein accumulates in the retina. These macular pigments are powerful anti-oxidants. As we get a bit older (wiser, smarter, cooler) these macular pigments tend to change. And not for the better. They get depleted and vision gets worse. There are a number of things that can cause Lutein levels to drop off:
- Diet low in Lutein
- Oxidative Stress from many different sources such as air pollution, arsenic and other bad stuff.
- Maybe age
Fortunately, there are things we can do to protect our vision.
- Don’t engage in nasty habits
- Eat well to protect your vision and keep your vision strong over time.
CrossFit Masters Nutrition: The Eyes Have It.
Most of us will notice vision changes in our forties and fifties. Its not just a need for reading glasses. Eyeball pigments (macular pigments) are needed for more than reading. The loss of pigment makes us lose some of our capacity for clear, central color vision. We may have a harder time with glare and with contrast. These things can make depth perception and driving a problem.
Researchers been investigating the role of lutein supplements as a means to counter these changes in vision. While we may not notice vision changes until we are in middle age changes and damage may occur decades before. If Lutein is depleted it cannot protect your eyes from day to day stress. This may cause damage to accumulate over time. People who spend a lot of time outdoors seem to lose macular pigments like Lutein. Loss of macular pigments is associated with increased risk of macular degeneration. Macular degeneration is a leading cause of blindness.
CrossFit Masters Nutrition: The study in brief.
The new study (Yao and Yuan 2013) looked at healthy, relatively young people. Ages ranged from 25 to 47. This study is especially interesting because the subjects did not have macular degeneration or other vision problems. Subjects were given a thorough eye exam and given Lutein supplements for a year. There were significant improvements in sharpness of vision, contrast sensitivity and sensitivity to glare. Nice to know that improving your diet and help your driving and night basketball skills. More studies are needed to see if increasing other macular pigments will also improve vision. Lutein must be obtained from the diet. The same is true for zeaxanthin. Its possible that increasing intake of zeaxanthin would also improve vision. Or that taking both would produce better results. More studies will tell.
CrossFit Masters Nutrition: Supplements or Real Food?
You can get Lutein supplements if you want to go that route, but the best choice is probably to get lutein from real food. Lutein is a carotenoid. Like Vitamin A. There are about 600 different carotinoids identified so far. Most vegetables will contain many different carotenoids. Some of these are also important for health. Good sources of Lutein include:
- Kale and other leafy greens
- Egg Yolks
- Carrots (Lutein in cooked carrots is more accessible)
- Other Yellow vegetables
If you are following the Paleo diet and eating lots of vegetables you are probably doing well in this department. If you are a vegetarian and eating lots of different vegetables you are probably doing well too.
Yao Y, Qiu GH, Wu XW, Cai ZY, Xu S, Liang XQ. Lutein supplementation improves visual performance in Chinese drivers: 1-year randomized, double-blind, placebo-controlled study. Nutrition. 29 (7-8): 958-964.
Loughman J, Akkali MC, Beatty S, Scanlon G, Davison PA, O’Dwyer V, Cantwell T, Major P, Stack J, & Nolan JM (2010). The relationship between macular pigment and visual performance. Vision research, 50 (13), 1249-56 PMID: 20394766
Feeney J, Finucane C, Savva GM, Cronin H, Beatty S, Nolan JM, & Kenny RA (2013). Low macular pigment optical density is associated with lower cognitive performance in a large, population-based sample of older adults. Neurobiology of aging, 34 (11), 2449-56 PMID: 23769396