February 11, 2002 at 7:41 PM EST - Updated July 2 at 9:45 PM
CLEVELAND (AP) - Watching television can increase the chances of developing Alzheimer's disease, according to a new study.
Researchers at Case Western Reserve University School of Medicine found that adults between 40 and 60 who watched a lot of TV were more likely to have Alzheimer's when they reached 70 or older, regardless of gender, income or education level. Each daily hour of television viewing in mid-life increased the risk of getting the disease by nearly a third.
Researchers questioned nearly 500 Clevelanders about their television-viewing habits. Spouses or other close relatives responded for those who couldn't answer themselves.
The findings are part of the latest work by neurologist Dr. Robert Friedland, who began in 1991 to look at how mental and physical activity affects the risk of getting Alzheimer's.
Friedland isn't saying television viewing causes Alzheimer's. It is, however, a sign of an inactive lifestyle and takes time away from more mentally challenging activities.
The research joins a growing number of studies supporting the theory that an active mind keeps the brain healthy.
Researchers at Columbia University in New York published a study in December tracking almost 2,000 people 65 and older over seven years. Those who engaged in high levels of reading, exercising or even just talking with friends reduced their risk of Alzheimer's by 38 percent.
"The brain is like any other organ in the body," Friedland said. "It ages better, with more health and better function, when it is used."
About 4 million Americans have Alzheimer's disease, which erases the memory until its victims forget even how to eat and other basic skills.
The brain tissue of an Alzheimer's patient is clogged with plaque deposits, consisting of abnormally clumped proteins, Friedland said. There is also a loss of connections between brain cells, which become tangled.
Mental activity increases the flow of blood to the brain, increases the connections of nerve cells to each other and increases the resistance to disease.
The healthy brain is better fortified to battle the debilitating effects of the plaque and tangles should they occur, Friedland said.
(Copyright 2002 by The Associated Press. All Rights Reserved.)