The Science of Health: The Heart-Brain Connection; December 2010; Scientific American Magazine; by Christine Gorman; 2 Page(s)
When the National Institutes of Health convened a panel of independent experts this past April on how to prevent Alzheimer’s disease, the conclusions were pretty grim. The panel determined that “no evidence of even moderate scientific quality” links anything—from herbal or nutritional supplements to prescription medications to social, economic or environmental conditions—with the slightest decrease in the risk of developing Alzheimer’s. Furthermore, the committee argued, there is little credible evidence that you can do anything to delay the kinds of memory problems that are often associated with aging. The researchers’ conclusions made headlines around the world and struck a blow at the many purveyors of “brain boosters,” “memory enhancers” and “cognitive-training software” that advertise their wares on the Web and on television. One of the panel experts later told reporters in a conference call that the group wanted to “dissuade folks from spending extraordinary amounts of money on stuff that doesn’t work.”
But did the panel overstate its case? Some memory and cognition researchers privately grumbled that the conclusions were too negative—particularly with respect to the potential benefits of not smoking, treating high blood pressure and engaging in physical activity. In late September the British Journal of Sports Medicine published a few of these criticisms. As a longtime science journalist, I suspected that this is the kind of instructive controversy—with top-level people taking opposing positions—that often occurs at the leading edge of research. As I spoke with various researchers, I realized that the disagreements signaled newly emerging views of how the brain ages. Investigators are exploring whether they need to look beyond the brain to the heart to understand what happens to nerve cells over the course of decades. In the process, they are uncovering new roles for the cardiovascular system, including ones that go beyond supplying the brain with plenty of oxygen-rich blood. The findings could suggest useful avenues for delaying dementia or less severe memory problems.