Oct. 5, 2011 -- Think you're unhealthy? You could be right, and your brain may be trying to tell you something.
A new study shows that people aged 65 and over who rated their own health as poor were 70% more likely to develop dementia than those who felt they were in good health.
Researchers say the results suggest that poor self-reported health without any clear medical explanation may be an early warning sign of dementia.
"People don't yet complain of memory troubles, but still they have a feeling that something is happening in their brain or their bodies that is not right," says researcher Christophe Tzourio, MD, PhD, a professor at the University of Bordeaux 2 in France.
Dementia occurs when there is loss of memory and other mental functions such as reasoning and decision making. The most common cause of dementia is Alzheimer's disease.
"We do know that the biological changes associated with Alzheimer's disease are actually occurring 10, 15, and maybe even as much as 20 years before an individual has some of the cognitive or memory issues," says Heather Snyder, PhD, senior associate director of medical and scientific relations at the Alzheimer's Association.
"It could be these individuals are noticing changes in their memory or thinking and reasoning ability in those early stages but it's not enough to be picked up in clinical diagnosis," she says.
Rating Your Own Health
Researchers say previous studies have already shown that people who rate their own health as poor are more likely to die or develop a disease than those who consider themselves healthy. But few studies have looked at the implications of poor self-rated health on the risk of dementia.
In the study, researchers followed a group of 8,169 people in France aged 65 and over for an average of about seven years. The participants were asked to rate their own health at the start of the study and then were screened for dementia at the end of the study.
The people in the study were not in a hospital or living in other types of institutions.
The results, published in Neurology, showed those who rated their health as poor were 70% more likely to develop dementia than those who considered their health good. Those who rated their health as fair were 34% more likely to develop dementia.
Researchers found self-rated poor health was an even stronger predictor of future dementia risk in people without any memory problems. Those without any memory complaints who rated their health as poor were twice as likely to develop dementia as those who said their health was good.
The study also showed poor self-rated health was associated with an increased risk of dementia caused by Alzheimer's disease as well as vascular or stroke-related dementia.
"Declaring that your health is not good clearly means something," Tzourio tells WebMD. "It could mean that you overall are not well, feeling less social, depressed, more anxious, or relying on drugs. Then, this process of losing social interaction [as a result of not feeling well] is part of the dementia process."
Previous studies suggest being socially and physically active may lower the long-term risk of dementia.
Researchers say people who rate their own health as poor may have a more difficult time participating in social and physical activities that might otherwise help prevent dementia.
Still, further large studies will be needed to better understand the link between self-rated health and dementia.
If those studies confirm these results, Tzourio says simply asking the question, "How do you rate your health?" may be a valuable tool for doctors and health care providers to be alerted to the risk of dementia in older people.
"It's a great self-contained question that gives a lot of powerful information," says Kellie Hunter Campbell, MD, assistant professor of geriatrics and palliative medicine at the University of Chicago Medical Center. "Self-reported health has been shown to predict a whole bunch of outcomes."
Campbell says asking about self-rated health is an easy thing to do and could prompt a health care provider to screen for dementia in people that might not otherwise appear to be at risk.