Macular degeneration, carotenoids
Lutein For Healthy EyesBy Dr. Gifford Jones
Today seven million North Americans Suffer from a devastating disease, macular degeneration. No longer can they enjoy the simple pleasures of reading or watching TV. These unfortunate people have lost their central vision. But there is a way to reduce the risk of this disabling problem.
The retina acts like the film of a camera conveying images to the brain. The big picture is sent by sensitive detectors present throughout the retina. The small picture, namely central vision is sent by the macula. It’s situated directly behind the lens, densely packed with visual detectors about the size of the “o”.
Stare someone in the eye at a distance of 20 feet and your looking at the macula. All the rest is peripheral vision. And it’s impossible to drive a car or see your grandchildren with only periph Stare someone in the eye at a distance of 20 feet and your looking at the macula. All the rest is peripheral vision. And it’s impossible to drive a car or see your grandchildren with only peripheral vision. You must have a healthy macula.
Dr. John Landrum, at Florida International University, Miami, Florida is a world expert on macular pigments.
Lutein, Dr. Landrum reports, is one of the two primary pigments, also called carotenoids, present in the macula. The other zeaxanthin, filters out damaging light.
Dr. Landrum studied the concentrations of pigments in the eyes of those with and without macular disease. This study revealed that people with the highest intakes of lutein and zeaxanthin had a 43 per cent less risk of macular degeneration.
This is not the first study that has linked a lack of carotenoids to macular disease. A report from the National Institute of Health found that those with the lowest dietary intake of carotenoids had a higher risk of macular degeneration.
The problem is that most people do not consume enough lutein and zeaxanthin rich fruits and vegetables to obtain the protection they need.
Dr. Linda Nebeling of the National Cancer Institute recently presented data showing the overall decline of lutein intake. This was particularly striking in those groups at risk for macular degeneration. For instance, between the years 1987 and 1992 lutein intake decreased by 16 per cent in men and women aged 40 to 69.
Not known is how much lutein and zeaxanthin are needed to maintain good vision. Dr. Landrum and his colleagues have shown that 30 milligrams (mg) of carotenoids daily result in large increases of lutein and zeaxanthin in the blood and macula.
In another study subjects took only 2.4 mg of lutein daily for six months. But with even these low doses blood levels of lutein and zeaxanthin increased as much as 300 per cent.
People who begin to develop macular degeneration complain of blurred or fuzzy vision. They have the illusion that straight lines, such as sentences on a page are waxy. Patients also become aware of dark or empty areas in central vision.
Severa; risk factors have been linked to macular degeneration. Some people have a family history of this disorder. Excessive sunlight exposure, smoking, female gender and patients who have a light-coloured iris are at greater risk.
Researchers believe that lutein and zeaxanthin protect the macula by absorbing harmful blue light from the sun’s rays. In addition, they act as antioxidants that neutralize free radicals.
Free radicals are harmful molecules, the end products of oxygen metabolism. In addition, free radicals are also triggered by tobacco smoke, air pollutants, certain drugs and environmental toxins.
So how can you reduce the risk of macular degeneration? The best way is to ensure that you have an adequate dietary intake of lutein and zeaxanthin. This means eating fruits and leafy vegetables that are rich in these carotenoids. And to take supplements of these carotenoids if you have a narrow diet.
But there is another way to obtain lutein of which most people are unaware. Several week ago I praised the benefits of Naturegg, the number one Omega-3 egg in Canada. It is rich in omega-3 fatty acids which helps to fight heart disease. The yolk of these eggs is also rich in lutein.
That is why I recently advised a patient with failing eyesight to eat omega-3 eggs. She quickly asked, “But won’t it increase my cholesterol?” I reassured her that several studies show that enjoying eggs for breakfast does not increase blood cholesterol in most patients. That’s why I’ve urged readers for years to trust farmers and cast a jaundiced eye at packaged supermarket foods.(0) Reader Feedback | Email Article | Email Us | Print friendly
Dr. Gifford Jones Bio
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W. Gifford-Jones M.D is the pen name of Dr. Ken Walker graduate of The Harvard Medical School. He’s been a ship’s surgeon, hotel physician and family doctor and later trained in surgery at McGill in Montreal, University of Rochester N.Y. and Harvard. His medical column is published by 60 Canadian newspapers and several in the U.S. He is the author of seven books. Dr. Walker has a medical practice in Toronto. His Web site is: http://www.mydoctor.ca/gifford-jones