More than 5 million Americans have Alzheimer's disease, and the nonprofit Alzheimer's Association projects that, barring major advances, 11 million to 16 million will have it by 2050—at an annual cost of $1.1 trillion in today's dollars. In May, the government announced the first national plan to combat Alzheimer's, and one focus is the role of beta-amyloid plaques in the brain, a leading suspect in this form of dementia. U.S. News spoke about progress against the disease with a leading researcher in the field, Reisa Sperling, head of the Center for Alzheimer Research and Treatment at Brigham and Women's Hospital in Boston and an associate professor of neurology at Harvard Medical School. Excerpts:
What do you see unfolding over the next couple of decades?
What we have now is what I would term "symptomatic therapy." Drugs that are FDA-approved for Alzheimer's disease help people stay functional a bit longer, but they're not really slowing the underlying disease process. I actually am optimistic about the outlook over the next 10 to 20 years, because I think we are realizing that Alzheimer's disease can be detected a decade before people have symptoms. That will allow us to move into the same type of prevention strategy that has been successful in cancer and heart disease.
Has anything proven effective yet in either staving off or slowing the disease?
Unfortunately, no. There are several anti-amyloid agents in large-scale trials that are due to report out this fall. However, those trials are being done at what we now recognize is probably the late stage of a 20-year disease process. And I'm afraid that may be too late for these particular mechanisms. The good news is that the agents are increasingly showing evidence that they have biologic activity, that they can lower amyloid in the brain and even affect what we call downstream processes, such as another key protein called tau. The issue is that we need to start both of those types of therapies, anti-amyloid and anti-tau, much earlier.
One of your specialties is early diagnosis. Are you seeing some important gains there?
We now have both imaging markers and biological markers in spinal fluid that can indicate the disease process very early, perhaps even before there are any symptoms. This is a huge advance. We screen for cholesterol and blood pressure before people have symptoms. We now have the ability to do that in Alzheimer's. The problem is we don't yet have large-scale studies to link these biomarkers to eventual clinical outcomes.
Given that there isn't any cure, might there be a downside in being able to make early diagnoses?
I don't believe that people who don't have symptoms yet should go out and get a PET scan or a spinal fluid test or even a genetic test, because it wouldn't change what I would recommend they do. I'd still recommend that they live a healthy lifestyle. What I'm working on is trying to do a prevention trial in people who have biomarker evidence of Alzheimer's disease but don't yet have any symptoms, and see if we could prevent the emergence of symptoms. That's what I think will be exciting over the next five years.
What are significant early warning signs of the disease?
For example, people worry they have Alzheimer's disease because they can't remember the actress's name in a film. That is not worrisome. But if they forget that they went to the movies at all, or forget what they were trying to remember, then I get worried. I also think that people losing interest in their hobbies and in social interaction is often a very concerning early sign. When people get lost driving even to familiar places, or get lost in an unfamiliar setting but can't figure out how to ask for help or reorient themselves, that's a real concern. One symptom that's very common is repeating questions multiple times.
Do you have advice for how people can best protect themselves, at any stage of life?
Physical exercise is showing more and more promise. I don't think there are definitive studies yet, but research does suggest that being in shape throughout life is helpful. And similarly, some exercise studies in patients who already have dementia show it seems to slow the rate of decline. There is some evidence that lower midlife cholesterol may be protective. And there's more and more evidence that early-life cognitively stimulating activities may be helpful. So one thing we can do is make sure we stay intellectually, socially, and physically active throughout our lives and help our kids start these habits early.