According to a study published Wednesday in the New England Journal of Medicine, dementia is on a serious decline with the risks going down about 20% per decade since the late 1970s; thing is, Scientist’s are struggling are struggling to explain the declining numbers.

Dementia On Decline, Baffling Scientists

Big dementia numbers being replaced with Alzheimer’s disease diagnosis

The study is far from rosy as baby-boomers and their growing life expectancy should bring a rash of new cases some time in the near future. Researcher’s expect that these longer lives will mean that while the chance of developing dementia may be down, the sheer number of people living longer lives will mean a health an financial toll is just around the corner.

The Alzheimer’s Association predicts that by 2025, over 7 million people over the age of 65 will be robbed of their ability to function, and their memories. Loss of memory, essentially, means loss of personality. If these numbers hold water it represents a 40% increase from today’s number. The same group believes that by 2050, Alzheimer’s will carry a price tag of $1.1 trillion.

A somewhat strange and sad note seems to be that the dementia numbers are going down in people who have at least a high school education.

“Can we, a couple of decades down the road, bend the arc? … Stroke used to be the second leading cause of death, and now it’s the fifth. Maybe we can do this for dementia, too,” said Sudha Seshadri who took the lead in the study.

Seshadri, a professor of neurology at Boston University School of Medicine, and her colleagues warned that while dementia/Alzheimer’s numbers are down it could simply be an anomaly. While there is little arguing the fact that doctors are better equipped each year to control heart disease and blood pressure that often sees dementia developing following a stroke, Seshadri was quick to point out that the numbers are not statistically significant.

Dementia and the Framingham Heart Study

Those numbers come from studying the data from the Framingham Heart Study which began in Massachusetts in 1948 when scientists began collecting health records of over 5,000 residents. In the nearly 60 years since, researchers have extended the study to include the offspring of the original participants in hoping a hope of finding a connection between heart disease, blood pressure issues, cholesterol and obesity.

Thanks to the addition of cognitive assessments to the database beginning in 1975. Researchers have been able to look at issues like dementia and yesterday’s publishing of the study is a result of this work.

“What I would say is we need to take that message to redouble our efforts, not to become complacent. We are doing something right,” Seshadri said. “So if we understand what we are doing right, we can perhaps activate it.”

While the news that dementia was ebbing, it wasn’t a terrific surprise as data sets outside the Framingham Heart Study have suggested that dementia is decreasing. The problem with the Framingham Heart Study, is that nearly everyone involved is white. No, it’s not their fault they are white, just that Framingham, Mass., hardly offers a diverse population.

While health care is improving and with it the prevention and treatment of cancer and heart disease, “many people think we can live even longer lives — but lives compromised by dementia, vision loss, and hearing loss,” wrote David Jones of Harvard Medical School and Jeremy Greene of the Johns Hopkins University School of Medicine in an editorial that was published yesterday in the same journal.  “Whether that fate is inevitable or whether these, too, are malleable scourges remains to be seen. … Even if death and taxes remain inevitable, cancer, CAD [coronary artery disease], and dementia may not.”