Healthy Eating: Essential for Saving Your Vision
Age-related Macular Degeneration (AMD) is one of the most common causes of irreversible vision loss in developed countries.
In the retina, the macula is located at the center; it is the exact point on the retina that we use to see small details and appreciate colors and shapes. Degeneration begins with small deposits around the macula area called drusen and with small retinal holes. In the early stages, known as “dry” AMD, the vision is not greatly affected, but it can then progress into what is known as “wet” AMD, characterized by fluid leakage into the area and the growth of fragile new blood vessels which can break and leak into the eye. The wet form of macular degeneration can be devastating to the vision, causing the loss of the ability to see well enough to read, appreciate color and even to recognize the faces of loved ones.
Presently, there is no cure for AMD, but it has been shown that its progression can be slowed, especially when diagnosed fairly early in the process. Preserving vision in the first eye has not been as successful as preserving it in the second eye; this is thought to be the result of better and more frequent monitoring as the first eye is followed for changes.
Treatments such as anti-vascular growth factor (VGF) injected into the vitreous is helpful, once an eye reaches late-stage AMD, to prevent the growth of new vessels that can leak fluids and block vision. Laser anti-coagulation has been used to seal off leaking vascular tissues as well. However, neither of these treatments is able to restore lost vision.
Research is progressing in genetic testing for AMD which can help identify those at risk to develop this condition so steps can be taken for early diagnosis and delay progression from dry to the wet forms.
Recent studies are showing that eating a healthy diet and/or using specific nutritional supplements is useful in slowing the disease down, as well as lowering the risk of cancer and delaying Alzheimer’s Disease or other dementias. It has not been shown, however, that these things can prevent AMD.
AMD is still not completely understood, but may be due to oxidation reactions in t retina. The important Age-Related Eye Disease Study (AREDS) did show that antioxidants were helpful in preventing up to 25% of the progression from early- to late-stage AMD.
Supplements and Diet
AREDS showed that increases from five to 13 times the recommended daily allowance of beta-carotene, vitamins C, E and the mineral zinc were effective in reducing the rate of progress of AMD.
A later study supported changes in lifestyle, including diet, and did show a positive link between food sources of antioxidants (the same as those used in AREDS) and lowered risk of AMD.
This particular study followed patients who were at least 55 years of age and who had no AMD in either eye at the beginning of the study. After an average span of eight years, those who had diets rated highly for vitamins C, E, beta-carotene and zinc were 35% less likely to develop AMD; eliminating those who used supplements rather than food sources from the analysis did not change the results.
Researchers involved in this study pointed out that a diet rich in several different antioxidants was more effective than those which relied on high amounts of any single one.
In order to get the vitamins, b-carotene and zinc levels linked with lower risk of AMD, specific recommendations are that you should consume daily six or more servings of vegetables and fruits, and include one cup of dark green and another of orange vegetables each week, three or more servings of whole grains, four to six ounces of meat, poultry or seafood (or bean equivalents), five to seven teaspoons of oils like olive or canola and about one ounce of nuts.
Several large studies also link eating fish at least twice a week with substantially lower chances of developing AMD. Too much total fat, particularly polyunsaturated fats which are found in fish, may increase the risk, however. This is thought to be because the chemical structure of polyunsaturated fat seems more vulnerable to oxidation reactions that are thought to cause damage to the eye.
In another study, women who chose foods with higher glycemic indexes had more than twice the rate of very early AMD; those diets tended to be high in sweets and refined grains and low in vegetables, fruits and whole grains. This link held even when researchers factored in the amount of fat and lack of antioxidant nutrients in their diets. Perhaps too many refined carbohydrates encourage inflammation and tissue damage; also, the shortage of nutrients and phytochemicals from healthful foods could also explain their higher risk for developing AMD.
It should be evident that eating a healthy diet with plenty of fruits, vegetables, whole grains and lean meats has plenty of benefits, even if the increased risk of AMD without them is ignored. Other studies show that a diet such as this is helpful in delaying onset of Alzheimer’s Disease for those at risk for that and other dementias. We all know, too, that eating right can help prevent certain cancers and that it doesn’t hurt our cardiovascular health, either.
Staying active, eating well and enjoying life are all important to keeping us healthy and happy; it’s a winning strategy, no matter what angle you’re looking at it from.