Alzheimer’s Disease – Latest Outlook
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
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.