For
more information or interviews, please contact:
Patricia Wilkinson, Manager, Media Relations and Communications, (416)847-2959, or 1-800-616-8816, pwilkinson@alzheimer.ca |
In Pursuit of a Cure
This is an exciting time for Alzheimer's disease research. Over
the last 10 years , great progress has been made, and there is
no doubt that major breakthroughs are on the horizon.
The Alzheimer Society of Canada is a leading funder of
Alzheimer research and research training in Canada. In 2007,
the Society and its partners funded research amounting to
$2 million, which supports both the biomedical and
the social/psychological fields.
While Canadian scientists rank among the top Alzheimer
scientists in the world, the fact remains that there is currently no
cure for Alzheimer's disease. Research remains the key to finding
a cure, and if a cure is to be found, Alzheimer research must be
made a higher priority in Canada, and more funding must be
given in support of Canada's world class researchers.
What is Alzheimer's disease?
Alzheimer's disease is a progressive and degenerative brain
disease that destroys memory, reasoning, orientation in time
and place, along with other cognitive functions. As the disease
progresses, it affects personality, mood, behaviour, and activities
of daily living. Alzheimer's disease is not a normal part of aging.
In Alzheimer's disease, multitudes of dense, irregular microscopic
spots or plaques develop all through the brain, and thread-like
tangles appear within the brain cells. The toxic effects of these
changes cause nerve cells to die, especially those involved in
memory and cognition.
Biomedical research
Biomedical researchers are working to try and understand exactly
how these adverse changes are brought about in the Alzheimer
brain, with the end goal of designing treatments to prevent their
development. As well, they are actively following a variety of
approaches to promote brain repair that will compensate for the
damage that has occurred.
New therapies
The plaques in the Alzheimer brain are made of a protein called
beta amyloid (A-beta), which is split off from a larger protein
molecule known as APP. While both APP and A-beta are present
in normal brains, the key problem in Alzheimer's disease is that
abnormally high amounts of A-beta accumulate in the brain,
overwhelming the normal processes that clear it away.
Researchers are investigating drugs that will inhibit the enzymes
from splitting off the A-beta, other drugs that prevent the
amyloid from depositing as plaques and still others that could
enhance the clearing system's efficiency. Many of these drugs
are in clinical trials and represent promising approaches for
a long-term therapy for Alzheimer's disease.
Researchers are also investigating how the abnormality that
causes tangles to develop arises, and are already devising drugs
to prevent this. Clinical trials are expected to begin soon.
An Alzheimer vaccine
There are promising developments in the search for an Alzheimer
vaccine. The first attempt, which showed positive results with
mouse models of the disease, was halted early in the first phase
of human trials in 2002 due to the development of potentially
lethal inflammation of the brain in some participants. However,
new vaccines are now being vigorously developed that are
predicted not to cause these adverse effects on the human
brain. The clinical trials of some of these have already been
extended from animals to humans, and the early news gives
definite hope that within five to seven years there could be a
vaccination therapy that could revolutionize the treatment of
Alzheimer's disease.
Early diagnosis
It has long been hoped that biological ‘markers' for Alzheimer's
disease would appear in various tissues of the body that could be
more easily recognized and studied than those in the brain itself.
New findings are offering hope that early diagnosis may become
possible through such biological markers, including things like
skin cells and cerebrospinal fluid.
Some important developments are also being made that relate to
Mild Cognitive Impairment (MCI), a condition that involves either
cognitive and/or memory impairment, but no other symptoms of
dementia that affect a person's daily activities. It is estimated that
85 per cent of people diagnosed with MCI develop Alzheimer's
disease within 10 years, so MCI research may help to provide
clues for early diagnosis of the disease.
Risk factors
Alzheimer's disease appears to be caused when the combined
effects of many risk factors, including age, genetics, lifestyle and
environmental factors, overwhelm the natural self-repair and
self-healing mechanisms in the brain. To this end, an increasing
amount of research is focusing on learning more about these
risk factors for Alzheimer's disease, what people can do to reduce
them, and also on ways to enhance the brain's self-healing
capacity. Studies so far have suggested that activities like
challenging the brain, being socially active, choosing a healthy
lifestyle and protecting the head from injury, help reduce the risk
of developing Alzheimer's disease. So does exercise, which has
been shown both to increase connections between brain cells, and
even to promote the development of new nerve cells in the brain.
Recovery of long-term memories
Recent animal studies offer hope that lost long-term memories
may be recoverable. When mice, genetically engineered to suffer
long-term memory lose through the death of nerve cells, were
put into an ‘enriched' environment (one with lots of opportunity
to play and to undertake explorative behaviour), the long-term
memory eventually reappeared, despite the loss of nerve cells.
Thus the memories were there, but couldn't be accessed until
new connections were made by the surviving cells. While this
science is still in its very early stages, the message is critically
important. Lost memories may not have disappeared forever.
Even after nerve cells have died, the recovery of these memories
may still be possible.
Other areas of research that could lead to new treatments
1. Promoting brain repair: Even when a truly successful
treatment for Alzheimer's disease appears, there will still be
a need to deal with the damage already caused in the brain.
Of great importance here is a class of substances called 'growth factors', which promote the health of nerve cells and
their ability to grow new connections with other nerve cells.
One critically important growth factor is called nerve growth
factor, or NGF, and studies which are testing its potential in
people with Alzheimer's disease are showing initial promise,
both at keeping nerve cells from dying and for
improving cognition.
2. Alzheimer's disease and diabetes: Research is showing that,
even when diabetes in the conventional sense is absent,
anti-diabetic drugs called glitazones can help maintain brain
function in people with Alzheimer's disease. The continued
testing of these drugs is based on the idea that in people
with Alzheimer's disease there may actually be a sort of
diabetes of the brain. This idea is supported by the
observation that when insulin was administered through the
nasal passage of people with Alzheimer's disease (which gets
it preferentially to the brain without going through the rest
of the body) memory and cognition improved in some cases –
a promise of future therapeutic measures.
3. Stem cell research: Stem cells are special cells derived from
bone marrow and other tissue that have not yet matured
into specific adult cells such as nerve cells or muscle cells.
Researchers have established how to induce stem cells to
change into nerve cells and are working on the difficult
problem of how to introduce them into human brains to
replace nerve cells lost as a consequence of diseases such
as Alzheimer's disease.
4. Statins: Cholesterol-reducing agents, called statins, are being
tested to discover if they are a safe and effective way to slow
the progression of Alzheimer's disease, including a lowering
of the abnormally increased levels of the A-beta protein in
the brain.
5. Anti-inflammatory agents:There are indications that people
routinely taking anti-inflammatory agents, such as aspirin
and other nonsteroidal anti-inflammatory drugs, are at a
decreased risk of developing Alzheimer's disease.
6. Cognitive rehabilitation: In this therapeutic approach,
people with Alzheimer's disease are subjected to a variety
of repeated memory and other cognitive testing procedures
by trained psychologists. The results are a marked slowing
in the progression of the disease.
For a more in-depth look at current research in Alzheimer's
disease, please download 'A Report
on Alzheimer's Disease and Current Research'.
Social/psychological research
Researchers in the social and psychological fields are working
to identify the personal, social and environmental factors that
affect people with Alzheimer's disease, with the hope of
improving caregiving techniques, and enhancing the quality
of life for both the person with the disease and their caregivers.
More information on social/psychological research will be
provided in an additional fact sheet, scheduled for release in
the spring of 2008.
[The contents of this document are provided for information purposes only and do not represent advice, an endorsement or a recommendation, with respect to any product, service or enterprise, and/or the claims and properties thereof, by the Alzheimer Society of Canada.]
|
