Tuesday, July 22, 2014
The rate of Alzheimer's disease and other dementias has been in the United States and some other developed countries in the recent decade, new studies shows.
Researchers in US found that compared to later 70’s the rate of dementia diagnosis was 44% lower in recent years. A second study, which reviewed research from England, the Netherlands, Sweden and the United States, found a similar pattern. The third study, meanwhile, found signs of progress in the space of only a few years: In 2004, older German adults were about one-quarter more likely to be diagnosed with dementia than in 2007.
"For an individual, the actual risk of dementia seems to have declined," probably due to more education and control of health factors such as cholesterol and blood pressure, said Dr. Kenneth Langa. He is a University of Michigan expert on aging who discussed the studies Tuesday at the Alzheimer's Association International Conference in Copenhagen.
The opposite is occurring in some underdeveloped countries that have lagged on education and health, where dementia seems to be rising.
More than 5.4 million Americans and 35 million people worldwide have Alzheimer's, the most common form of dementia. It has no cure and current drugs only temporarily ease symptoms.
A drop in rates is a silver lining in the so-called silver tsunami — the expected wave of age-related health problems from an older population. Alzheimer's will remain a major public health issue, but countries where rates are dropping may be able to lower current projections for spending and needed services, experts said.
Why is the rate of new dementia cases apparently dipping? Better cardiovascular health could be one reason, said Claudia Satizabal, a researcher at Boston University School of Medicine, who led the U.S. study.
Her team found that over the years, people's average blood pressure and cholesterol levels improved, and their rates of smoking, heart disease and stroke declined.
A number of studies have linked better cardiovascular health to a lower risk of Alzheimer's, possibly because a healthy heart and blood vessels are more efficient at delivering oxygen and energy to brain cells.
Also in general people are more educated now than they were decades go and studies have proved that higher education leads to lower Alzheimer’s risk or late inset of the disease. Older people who stay mentally active by reading, taking classes, playing games or socializing have late onset of dementia.
Researchers from the German Center for Neurodegenerative Diseases say that claims data from Germany's largest public health insurance company suggest that new cases of dementia declined significantly between 2007 and 2009 in men and women.
Dementia prevalence — the proportion of people with the disease — also declined dramatically in women ages 74 to 85.
The trends corresponded with fewer strokes and better treatment of high blood pressure, cholesterol and diabetes, and more education, they said.
In countries where dementia appears to be declining, the rise in obesity and diabetes threatens to undo progress.
What's really needed are clinical trials that test the idea that lifestyle choices and better cardiovascular health can stave off dementia.