THURSDAY, July 1 (HealthDay News) -- Too much Wheel of Fortune and CSI may not be good for seniors' mental state, new research suggests.

Researchers analyzed data on nearly 4,000 Americans ages 15 to 98 and found that adults over age 65 spent almost three times more of their waking hours watching TV than younger adults.

But while the younger folks considered vegging out in front of the TV relaxing and relatively pleasant compared to their other daily activities, older people found TV less enjoyable, according to the study. While watching TV, older people reported more feelings of sadness than younger people, and they found shows less relaxing as well.

Ironically, of all leisure and social activities the older adults engaged in, TV watching was the most common, according to the study. But unlike other leisure-time activities -- such as socializing or getting exercise -- it was linked to lower life satisfaction.

Researchers pointed out that other data suggests excess TV watching is also associated with poorer cardiovascular and bone health, a higher risk of obesity and type 2 diabetes, lower life satisfaction, less frequent engagement in social and physical recreation and increased risk for dementia.

Despite watching more TV, older people overall were more satisfied with their lives, happier and less stressed than younger people, the study found.

"We found older people spent more time in a positive mood and less time in a negative mood than younger people," said lead study author Colin A. Depp, an assistant professor of psychiatry at the University of California, San Diego's Stein Institute for Research on Aging. The exception seemed to be that older people "are watching a great deal more TV," he said, but unlike younger people, they were not enjoying it that much. The heavy TV watchers also reported more dissatisfaction with their lives.

The study is published online in the American Journal of Preventive Medicine in advance of print publication in the August issue.

Previous research shows American households watch on average 4.5 hours of TV a day. While much of the concern over viewing habits has been directed at children, research suggests no one spends more time glued to the tube than older folks, according to background information in the article.

People over age 65, in fact, spend more than 25 percent of their waking hours watching TV. The study found that people 76 and older watched the most TV, while those aged 26 to 35 spent the least amount of time in front of it -- less than 10 percent -- but tube time slowly climbed as people aged.

The data was from a large, nationally representative sample collected in 2006 by the Center for Health and Well Being at Princeton University. Study participants were asked to keep a diary of how they spent their day and how they felt doing certain activities.

Making other engaging activities available to the elderly could reduce their reliance on TV, the authors said.

Dr. Martin Gorbien, director of geriatric medicine and palliative care at Rush University Medical Center in Chicago, said the more important question isn't whether older people like television, but why some watch so much of it.

"Among seniors, we have issues of isolation, undiagnosed and untreated depression and loneliness," Gorbien said. "If you are depressed and lonely, you can be watching the most exciting thing in the world and it's not going to make you feel good."

Some people also watch lots of TV because they feel they don't have any other options -- perhaps they no longer drive, their family lives far away, friends have died, or they have chronic illnesses or pain that make it difficult to do other activities.

"What we would need to do is talk to them about their mental well-being, their physical well-being, their relationships and their social network," Gorbien said. "Some people feel, 'What else do I have than watching TV?'"

More information

See NIHSeniorHealth for more on staying healthy in old age.