Alzheimer’s research has suffered several serious setbacks in recent months as several clinical trials of possible drug therapies were not successful. But a new study published in medical journal The Lancet gave the Alzheimer’s researchers reason to be hopeful once again.
A better understanding of Alzheimer’s
Scientists used to think that Alzheimer’s started to affect the brain very shortly before symptoms such as memory loss and confusion became evident. But several studies over the past few years paint a very different picture. Alzheimer’s, in fact, begins to compromise the brain years and sometimes decades before any symptoms develop. The early symptoms of Alzheimer’s disease also are easily mistaken for normal signs of aging, further delaying a proper diagnosis. All this time allows the disease to progress and damage the brain before it is even suspected, much less diagnosed.
As a result, most of the studies on Alzheimer’s disease are done on people whose brains have sustained significant damage from the disease. And since there, as yet, is no way to replace dead brain tissue, the best treatments currently available for Alzheimer’s disease can only slow the progress of brain decay. So far, no treatment can halt or reverse the damage caused by the debilitating disease.
As the Baby Boomer generation moves into retirement and old age, the need to develop preventive treatments becomes more pressing.
An early indicator of Alzheimer’s disease
New research, however, from Banner Alzheimer’s Institute in Arizona, Boston University and the University of Antioquia, Colombia found the presence of a rare genetic mutation called PSEN1 almost certainly means a person will develop Alzheimer’s.
The study also determined that people with the PSEN1 mutation showed signs of amyloid beta plaque build up in the brain--a tell tale sign of Alzheimer’s disease--up to 20 years before any Alzheimer’s symptoms were evident.
The 20-year advance warning is the most promising part of the study. That potentially gives researchers an opportunity to study how Alzheimer’s affects the brain in the early stages of the disease.
Putting the study into perspective
According to Dr. P. Murali Doraiswamy, a professor at Duke University and scientific advisor at the Alzheimer’s Foundation of America, the findings are indeed ground breaking but, like most studies, need to be put into perspective.
“This finding applies to people with rare mutations for early onset Alzheimer’s. What it is telling us is that there is an interplay between genetics and lifestyle, and that in people with inherited aggressive mutations, the timing of Alzheimer’s can be vastly accelerated,” said Doraiswamy.
So, while the study is promising, its immediate impact would involve only a small number of people with a very specific genetic mutation.
A matter of timing
But, according to Doraiswamy, the study does provide a “roadmap for how genetic risk changes the timeline of development of silent Alzheimer’s changes in the brain”.
In other words, if scientists can identify when Alzheimer’s disease begins, they could better determine when prevention therapy could be most effective. Also, by carefully observing the way Alzheimer’s disease develops in the brain, scientists could be able to design drugs that target those specific changes--hopefully making a preventive treatment more effective and possibly even clearing a path for a cure.
Better ways to screen
Apart from drug therapies, the new study could also improve early detection methods. According to Doraiswamy, the research will help identify which brain scans could best detect the disease before it begins to do its damage. It could also help determine which kinds of scans will best monitor the effects of successful treatments.
What happens now?
The study team behind The Lancet paper is already planning a large prevention trial based on these findings, the results of which will become available in several years. As a result of the research, about a dozen other studies are being planned, primarily to explore the early stages of the disease.
“The next decade is going to be very critical for our field in that we will be doing several rigorous prevention trials that will offer the most definitive test of whether our theories of Alzheimer’s are right or wrong,” said Doraiswamy. If the theories are correct, it will be “one of the biggest breakthroughs in all of medicine”.
What’s the bottom line?
“The study by itself does not change [the current screening practices for Alzheimer’s disease] since it is applicable only to people who carry a rare mutation. Nevertheless, it points to the importance of early detection,” said Dr. Doraiswamy.
About 25 percent of Americans have an inherited genetic risk for Alzheimer’s disease, but many more are at risk due to lifestyle factors. A growing body of research points to heart disease, high blood pressure, high cholesterol and diabetes as risk factors for Alzheimer’s disease. The good news is that most of these conditions are preventable with a healthy lifestyle.
The bottom line: Practice a healthy lifestyle and if you suspect dementia or Alzheimer’s disease, arrange to get screened for the disease.
Interview with Dr. Murali Doraiswamy, November 8, 2012.
Medical News Today, Alzheimer’s disease could be detected over 20 years before symptoms appear. (Noember 6, 2012). Retrieved from: http://www.medicalnewstoday.com/articles/252402.php.
Alzheimer’s Association, What is Alzheimer’s? Retrieved on November 8, 2012 from: http://www.alz.org/alzheimers_disease_what_is_alzheimers.asp
Published On: November 13, 2012