Age-related macular degeneration (AMD) is the main cause of visual impairment in Western countries. It affects the central region of the retina, the macula lutea, at which visual acuity is the greatest.
What is the macula?
The macula is a small area just two millimeters wide, located in the back of the eye, in the middle portion of the retina. The center portion of the macula is referred to as the fovea, and it is responsible for central vision. (See diagram below.)
For reasons scientists have yet to pinpoint, parts of the retina and the macula become diseased. As AMD progresses, tiny, fragile blood vessels begin to develop in the retina. These vessels often leak blood and fluid that damages the retina even further.
Some warning signs of AMD:
- Blurred vision (may be the first symptom)
- Straight lines begin to appear crooked
- Dark or empty spaces may block central vision
The carotenoids lutein and zeaxanthin are the predominant pigments in this area. Some studies have shown a reduced risk of AMD in subjects with a higher intake of lutein and zeaxanthin or higher plasma concentrations of lutein and zeaxanthin.
Ophthalmology. October 2002;109(10):1780-7.
Dr. Mercola's Comments:
Lutein (LOO-teen) is a carotenoid found in vegetables and fruits. Lutein is just as important to health, or more so, than beta-carotene.
Lutein acts as an antioxidant, protecting cells against the damaging effects of free radicals.
- Lutein is not made in the body.
- Lutein must be obtained from food or vitamin supplements.
- Lutein is found in large amounts in green, leafy vegetables such as spinach.
However, most Americans simply don't eat enough fruits and vegetables rich in carotenoids, such as lutein. Ask yourself the following questions:
- Are you too busy to eat healthy meals?
- Do you eat a lot of fast food?
- Do you not eat enough dark green, leafy vegetables?
Lutein is easy to add to your diet if you eat plenty of spinach and other green, leafy vegetables. Every time you eat a spinach salad or a serving of kale or turnip greens, your body is getting high levels of lutein.
The problem is that a lot of people don't like these foods or don't eat enough of them.
So how do you get enough lutein in your diet?
- How much lutein is enough?
Nutrition experts currently use 6 milligrams a day as a reliable guideline.
| Lutein Sources | |
| Best food sources | Per 1/2 cup |
| Kale, cooked | 10mg |
| Collard greens, cooked | 7.7mg |
| Spinach, raw | 3.3mg |
| cooked | 6.3mg |
| Broccoli, raw | 1mg |
| cooked | 1.7mg |
| Brussels sprouts, cooked | 1.7mg |
| Corn, cooked | 1.2mg |
Lutein is one of over 650 carotenoids. Beta-carotene is probably the most famous of the carotenoids. The bioavailability of carotenoids is determined by the food source and interactions with other items in it. Studies with beta-carotene and lycopene have shown that association with a lipid matrix increases the bioavailability of these carotenoids. Carotenoids in the plant will decrease their bioavailability.
That is why there is a difference in the table above in cooked vegetables having more lutein. However, when you break down the plant cell by decreasing food particle size as you do in juicing, you maximize the bioavailablity of the carotenoids and all other nutrients-far more so than cooking. Unfortunately, most all of the nutrient databases don't acknowledge this, and there are no references that one can cite to demonstrate this.
It is important to note that lutein is an oil-soluble nutrient, and if you merely consume the above vegetables without some oil or butter you can't absorb the lutein. So if you are consuming vegetable juice, it would be wise to use some olive or cod liver oil in the juice to maximize your lutein absorption, as well as the absorption of other important nutrients like vitamin K.
Most people don't know that lutein is also present in egg yolks. There is about 0.25 mg in each egg yolk-in a highly absorbable nearly ideal form, especially if you don't cook it. Egg yolks also have zeaxanthin in an equal amount. Zeaxanthin is another carotenoid that is likely to be equally as effective as lutein in preventing macular degeneration.
If you consume four raw egg yolks per day mixed in with your vegetable pulp, you will be getting 1 mg a day of lutein and zeaxanthin. Your absorption of each will be close to 100 percent, which may be the equivalent of consuming half a cup of unjuiced kale or collards.
I consume about one cup of juiced collards in my quart of juice in the morning, along with four raw egg yolks in my pulp. This means that I am likely getting close to 20 mg of lutein a day, and I am quite certain that macular degeneration is not in my future.
Another important consideration is iron level, as iron is a potent oxidant stress that can clearly damage many sensitive tissues in your body. I will be posting a major article on this subject in the near future.
Related Articles:
American Journal of Clinical Nutrition, August 1999 Vol. 70, No. 2, 247-251 Full Text Article
Avoiding Visual Degeneration
Don't Be
http://articles.mercola.com/sites/articles/archive/2002/11/06/blindness.aspx
