Dementia rates are falling, according to a new report published in the New England Journal of Medicine.
Using data obtained from the Framingham Heart Study, dementia rates have fallen by 44 percent since the late 1970s and early 1980s. Fox News reports that the most significant drop was among people who graduated high school.
The study pointed out that all causes of senility fell, especially dementia caused by vascular diseases, such as stroke. Cases of Alzheimer’s disease also declined, but not nearly as dramatic, leading researchers to think it was a statistical coincidence.
Dean Hartly, director of science initiatives with the Alzheimer’s Association, said there is certainly a downward trend for Alzheimer’s, but specific lifestyles of the participants in the study may have lowered the overall risk for a brain disease.
As the average age of the population is higher and life expectancy has been increasing, the number of people entering the age range when dementia begins to set in has also increased. According to study coauthor Dr. Sudha Seshadri, a professor of neurology at the Boston University School of Medicine, the falling dementia rates do not necessarily mean the overall number of cases will also decline.
“We don’t know completely what’s bringing down the rates. The good news is, we are doing something right. The bad news is we need to understand this much better if we want to effectively continue the trend.”
Starting in 1948, the Framingham Heart Study monitored the medical records of thousands of residents in a Massachusetts town west of Boston. The new report examined dementia rates from the records of 5,205 patients obtained in four five-year blocks.
According to the report, approximately 3.6 percent of people aged 60 years and older in 1977 had dementia, while the rate fell to 2.8 percent for another group who were over 60 in 1986. The rate then fell to 2.2 percent in 1992, then two percent for the most recent 2008 data.
“It’s very good news,” said Dallas Anderson, an epidemiologist with the National Institute on Aging, part of the National Institutes of Health, which funded the study. “We’re seeing one generation after another where the risk is going down.”
The falling dementia rates may coincide with the decline in rates of other medical conditions, like stroke, heart failure, and atrial fibrillation. Treatments for these conditions have also improved over the years. Yet researchers say this does not entirely explain the decreasing trend.
The study authors noted an interesting relationship between the dementia rate and education. Residents that had not graduated high school had no measurable decline in dementia.
Although not involved with the report, Dr. Paul Schulz, a dementia neurologist at the University of Texas Health Science Center in Houston, speculates that people with more education generally have more access to healthcare and go to the doctor more often. He also thinks that dementia symptoms may take longer to show up in people who have more cognitive ability to lose.
“People who have more education may be blessed with more brain power. They may have more ability to lose function before they develop symptoms. In this study, they’re speculating that getting more education might be valuable, but it might be a chicken and egg question here.”
The average age when dementia was diagnosed went up as time passed. In the 1970s the average age when dementia set in was 80, while the age increased to 85 in the most recent group.
“Rising educational levels might have contributed to the 5-year delay we observed in the mean age at onset of clinical dementia,” the researchers said.
The researchers noted that the Framingham Heart Study has one significant drawback. The participants were overwhelmingly of European ancestry, so the findings may not repeat if the groups were expanded to include members of other races and ethnic backgrounds.
In a related Inquisitr report, researchers from the Institute of Public Health at Cambridge University recently discovered that dementia rates are falling in the U.K. as well.
As reported by USA Today, the Alzheimer’s Association estimates that 5.3 million Americans currently have Alzheimer’s and one-third of seniors die with dementia. Health experts predict the dementia rate to increase 40 percent by 2025, to roughly 7.1 million.
Hartly suggests people that exercise, eat right, and interact socially have a better chance of avoiding brain diseases like dementia and Alzheimer’s. He also noted that more funding is needed for further studies before researchers can definitively determine if dementia rates are actually falling.
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