By Hollie Harris
OUR population is getting older, but a study has found the percentage of seniors with dementia is actually declining.
In the study, the researchers analysed information from a nationally representative sample of about 21,000 US adults aged 65 and older who were tested for dementia from 2000 to 2012.
In 2000, 11.6 percent of older adults had dementia, but that number dropped to 8.8 per cent by 2012.
Although some previous US studies had suggested the prevalence of dementia was declining in recent years, those studies were not representative of the entire US population.
The study’s lead author Dr Kenneth Langa said the new findings added to a growing body of evidence that this decline in dementia risk was a real phenomenon.
“The expected future growth in the burden of dementia may not be as extensive as once thought,” Dr Kenneth Langa said.
According to the National Institutes of Health, dementia is not a specific disease, but rather a group of symptoms, which can include problems with thinking and solving problems, as well as personality changes.
The risk of developing these symptoms has also been linked to other factors, like education, the new study suggested.
Researchers found that the people in the study who had more years of education had a lower risk of dementia.
Those with 16 years or more of education were about 70 per cent less likely to have dementia, compared with those who had less than 12 years of education.
During the study period, the average number of years of education among participants increased from 12 to 13 years.
More years of education may help protect against dementia in a number of ways, the researchers said.
Spending more years in school may help the brain’s “cognitive reserve”, meaning the brain may be better able to compensate for abnormalities that occur in older age.
Having more years of education can also allow people to obtain more cognitively challenging jobs, which could also help protect the brain, the researchers said.
And people who have more years of education may also be more likely to exercise and eat healthy, and less likely to smoke, which are all behaviours that are linked with better brain health.
Interestingly, the researchers noted that the drop in dementia prevalence occurred despite increases in the rates of certain conditions that can increase the risk of dementia: diabetes, high blood pressure and obesity.
The researchers said they suspect that better treatment of cardiovascular disease and diabetes may have also contributed to the decline in dementia.
