Age-related macular degeneration (AMD) is the leading cause of severe vision loss for seniors. Learn what causes AMD and the benefits lutein may bring.
The macula is the area of the retina where images are focused. It is the portion of the eye responsible for fine vision. Age-related degeneration of the macula is the leading cause of severe visual loss in North America in persons aged 55 years or older.
Individuals with macular degeneration may experience blurred vision; straight objects may appear distorted or bent; there may be a dark spot near or around the centre of the visual field; and while reading, parts of words may be missing. People with macular degeneration generally have good peripheral vision; they just can’t see what is directly in front of them.
The major risk factors for age-related macular degeneration (ARMD) are smoking, aging, atherosclerosis (hardening of the arteries), and high blood pressure. Apparently, the degeneration is a result of free-radical damage as well as decreased blood and oxygen supply to the retina.
A diet rich in fruits and vegetables may be associated with a lowered risk for ARMD. Presumably, this protection is the result of increased intake of antioxidant vitamins and minerals. However, various nonessential food components, such as lutein and the flavonoids from blueberries, are proving to be even more significant in protecting against ARMD than traditional nutritional antioxidants, such as vitamins C and E and the mineral selenium.
Taking a lutein supplement may help to halt and even reverse macular degeneration.
Several studies have now shown that taking a lutein supplement increases both the lutein content as well as that of a related carotene, zeaxanthin, within the macula. It appears that increasing the lutein content within the macula is linked to improvements in visual function in people suffering from ARMD.
For example, in one study (the Lutein Antioxidant Supplementation Trial, or LAST) it was shown that patients who took 10 mg of lutein daily experienced a 50 percent increase in macular pigment density. This may have led to improvements in several symptoms, including glare recovery, contrast sensitivity, and visual acuity.
In population studies, participants showing protection from macular degeneration were estimated to have eaten about 6 mg of lutein per day from food. This amount appears to be a reasonable supplementation level for prevention. In individuals with existing macular degeneration, my recommendation would be to take 20 mg daily for a minimum of three months to achieve saturation levels within the macula. After this time, a maintenance dosage of 6 to 10 mg is sufficient.