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CURWOOD: Just ahead: a monster at your local pond. But first, this environmental health note from Diane Toomey.
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TOOMEY: Macular degeneration is the leading cause of blindness among Americans over 60. The condition is caused when the macular, or central portion of the retina, either becomes clouded with fatty deposits or fluid from leaky blood vessels. Patients who have the condition can end up with crippling loss of their straight-ahead vision. Though the cause of macular degeneration is unclear, risk factors include smoking and advancing age. There's no cure for the condition, but now, the results of a new study may indicate a way to slow its progression. Harvard researchers followed 261 people with mild macular degeneration. They found that, over the course of about four and a half years, overweight patients were more than twice as likely to have their vision deteriorate compared to those not overweight. The researchers also found that physical activity seemed to slow the progression of the disease. People who vigorously exercised at least 3 times a week had a 25 percent slower rate of disease progression compared to those who didn't exercise at all. Researchers don't know how weight and exercise influence macular degeneration, but they suspect they may effect the blood vessels that remove waste products from the retina. That's this week's health update. I'm Diane Toomey.
CURWOOD: And you're listening to Living on Earth.
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