News reports of research into Alzheimer's disease July - December 2006
To search by subject, go to Alzheimer's subject index.
Return to Alzheimers main page for monthly index
There's a glossary of terms used in Alzheimer's research.
Disclaimer:
This section began as an offshoot of my
gathering of news items about memory. I am not a medical expert. My
background is in psychology. The information I have gathered here should
not be taken as providing any advice.
December
New way to target Alzheimer's disease
In a series of studies in
transgenic mice, a synthetic
peptide designed to block the interaction between
apolipoprotein E and
amyloid-beta protein
reduced the aggregation of toxic amyloid protein in the brain by around
50%. The treated mice showed no memory decline.
The study was published in the December 5 issue of the
Proceedings of the National Academy of Sciences.
Full reference
The full text is available at
http://www.pnas.org/cgi/content/full/103/49/18787
http://www.eurekalert.org/pub_releases/2006-12/nyum-sda120406.htm
Androgen therapy may slow progress of Alzheimer's disease
Recent studies have suggested a link between testosterone loss in men
and Alzheimer’s. A new study has now found a correlation between low
testosterone and elevated
beta-amyloid, providing
more support that testosterone depletion in aging men increases the risk
of Alzheimer’s. Testosterone belongs to a group of steroid hormones
called androgens. The mouse study found that androgen therapy was
successful in preventing beta-amyloid accumulation and cognitive decline
in castrated mice.
The findings were published in the December 20 issue of
The Journal of Neuroscience.
Full reference
http://www.eurekalert.org/pub_releases/2006-12/sfn-tm121906.htm
Compound shows promise for early detection of Alzheimer's disease
A new molecular marker called FDDNP has been found to track the
progression of Alzheimer’s in PET scans more effectively than other
markers, giving hope of earlier, more accurate diagnosis of the disease.
The study was published in the December 21 issue of the
New England Journal of Medicine.
Full reference
http://www.eurekalert.org/pub_releases/2006-12/nioa-nic121906.htm
http://www.eurekalert.org/pub_releases/2006-12/uoc--nit121506.htm
Protein 'fingerprint' in spinal fluid could spot Alzheimer's disease early
In a pilot study, a panel of 23
protein
biomarkers in
cerebrospinal fluid has been found to be over 90% sensitive in
identifying people with Alzheimer's disease.
The research was published online December 13 in
Annals of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2006-12/cuns-pi120706.htm
Hypertension drugs might help Alzheimer’s
A project to determine whether drugs that are already commercially
available for treatment of other disorders might help in treating
Alzheimer’s disease using in vitro methods has identified several
hundred drugs as having promise in preventing
beta-amyloid
build-up, of which seven are commonly prescribed to treat hypertension.
One drug in particular was identified as effective in blocking the
accumulation of beta-amyloid in the brain and preventing the
deterioration of cognitive performance: Propranololo-HCL (Inderal), a
drug widely prescribed to treat high blood pressure in elderly patients.
Of course, clinical trials will need to occur before this can be
confirmed.
The research was reported at the American College of
Neuropsychopharmacology’s (ACNP) annual conference December 3 - 7, 2006,
in Hollywood, FL.
http://www.eurekalert.org/pub_releases/2006-12/g-nsf120106.htm
November
Higher level of certain fatty acid associated with lower dementia risk
A nine year study of 899 participants in the
Framingham Heart
Study (average age 76 years) has found that those with the highest
levels of an omega-3 polyunsaturated fatty acid known as docosahexaenoic
acid (DHA) had a 47% lower risk of developing dementia and 39% lower
risk of developing Alzheimer's. Among the participants who completed the
dietary questionnaire, those in this top quartile of blood DHA levels
reported that they ate an average of .18 grams of DHA a day and an
average of three fish servings a week. Those in the other quartiles ate
substantially less fish.
The report appeared in the November issue of
Archives of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2006-11/jaaj-hlo110906.htm
Memory complaints early warning for Alzheimer's
A post-mortem study of 90 older adults from the Rush Memory and Aging
Project found that those who had yet to have any clinical symptoms of
Alzheimer's disease still showed a strong link between their
self-reported memory complaints and brain pathology associated with
Alzheimer's disease.
The findings were reported in the November issue of
Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2006-11/rumc-cam113006.htm
Counseling Alzheimer's caregivers postpones the nursing home
A long-running study of 406 people caring for a spouse with dementia
has found that a program of individual and family counseling sessions
and ongoing support for caregivers delays by an average of 1.5 years the
time when people with dementia are usually put in nursing homes.
The study was published in the November 14 issue of
Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2006-11/nyum-cac110806.htm
Individualized counseling helps caregivers
A study of 642 people who were caring for a relative with Alzheimer's
disease or a related disorder has found that those who participated in a
counseling program were less likely to suffer depression and felt more
confident and able to deal with caring for their relative. Hispanic and
white participants saw the greatest benefit. In African-Americans, the
intervention was effective among spouse-caregivers, but relatively
ineffective among caregivers who were caring for a relative other than
their husband or wife. Hispanics had the greatest improvement in
reduction of caregiver depressive symptoms and problem behaviors of the
recipient. Whites saw the most impact in the area of social support and
African-American spouse-caregivers had the most positive outcome in
reducing the caregiver burden and improving self-care.
Results were published in the November 21 issue of
Annals of Internal Medicine.
Full reference
http://www.eurekalert.org/pub_releases/2006-11/uopm-idc111506.htm
http://www.eurekalert.org/pub_releases/2006-11/nioa-npe111606.htm
New dementia screening tool detects early cognitive problems
A new screening tool for dementia — the Saint Louis University Mental
Status Examination (SLUMS) — appears to work better in identifying mild
cognitive problems in the elderly than the commonly used Mini Mental
Status Examination — particularly for the more educated patients. It
takes a clinician about seven minutes to administer the SLUMS, which
supplements the Mini Mental Status Examination by asking patients to
perform tasks such as doing simple math computations, naming animals,
recalling facts and drawing the hands on a clock. The SLUMS is available
at this link
http://medschool.slu.edu/agingsuccessfully/pdfsurveys/slumsexam_05.pdf
The study appeared in the November issue of the
American Journal of Geriatric Psychiatry.
Full reference
http://www.eurekalert.org/pub_releases/2006-11/slu-nds103006.htm
What nerve fibers need to form connections
A discovery that cholinergic neuronal circuits rely on
neurotrophin-3, a chemical that stimulates nerve growth, suggests a
new approach to a therapy for Alzheimer’s. The brains of Alzheimer's
patients show a marked decline in these cholinergic circuits, suggesting
that a neurotrophin-3 therapy may be beneficial.
Study results appeared in the December 1 issue of
Neuroscience.
Full reference
http://www.eurekalert.org/pub_releases/2006-11/uoc--nfn111706.htm
October
Marijuana may slow progression of Alzheimer's disease
New evidence suggests that marijuana — which has strong
anti-inflammatory effects — may contain compounds that slow the memory
loss associated with Alzheimer's disease. Treatment with a synthetic
compound similar to marijuana (WIN-55212-2) reduced inflammation in
older rats and substantially improved their memories.
The researchers presented their findings October 18 at the annual
Society for Neuroscience meeting in Atlanta.
http://www.eurekalert.org/pub_releases/2006-10/osu-lb101206.htm
http://www.sciencedaily.com/releases/2006/10/061018151055.htm
Anesthetics a risk factor for Alzheimer’s?
The link between surgery and cognitive problems has long been noted,
but it’s never been clear whether postoperative cognitive dysfunction
was the result of the surgery itself or the anaesthetics. Now animal
studies and test tube experiments are beginning to show that certain
anaesthetics reduce the rate at which brain cells are born and develop.
The latest study reveals that the inhaled anaesthetics halothane and
isoflurane encourage clumping of
beta amyloid protein, as
does the commonly used intravenous anaesthetic propofol, at least at
higher concentrations — suggesting that giving elderly patients certain
general anaesthetics could increase their risk of developing Alzheimer's
disease. The intravenous anaesthetic thiopental appears to have no
effect on the proteins.
The study was presented at the annual Society for Neuroscience Meeting
held in Atlanta, Georgia, October 14-18.
http://www.newscientist.com/channel/health/mg19225753.900-alzheimers-alert-over-anaesthetics.html
http://www.eurekalert.org/pub_releases/2006-10/ns-aao102506.htm
Omega-3 fatty acids may slow cognitive decline in some patients with very mild Alzheimer's disease
Several studies have shown that eating fish, which is high in omega-3
fatty acids, may protect against Alzheimer's disease. A Swedish study
has now tested whether supplements could have similar effects. Patients
with mild-to-moderate Alzheimer’s who took 1.7 grams of DHA and .6g of
EPA showed the same rate of cognitive decline as those taking a placebo,
however, among a subgroup of 32 patients with very mild cognitive
impairment, those who took the fatty acids experienced less decline in
six months compared with those who took placebo. It may be that
anti-inflammatory effects are an important reason for the benefit,
potentially explaining why effects were seen only in those with very
early-stage disease, when levels of inflammation seem to be higher.
The study was published in the October issue of
Archives of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2006-10/jaaj-ofa100506.htm
Computer-based 'games' enhance mental function in Alzheimer's patients
An interactive multimedia internet-based game has been shown to
benefit cognition in patients with Alzheimer's disease more than classic
exercises of mental stimulation commonly used with dementia patients.
The study compared patients receiving no cognitive intervention, those
enrolled in a daily program that included 2.5 to 3.5 hours of cognitive
stimulation tasks, musical therapy, arts and crafts, physical activity
and programs that reinforced instrumental activities of daily living,
and those who also used an interactive multimedia internet-based system
which allowed them to carry out a variety of different cognitive
stimulation tasks at varying levels of difficulty throughout the day.
After 12 weeks, both intervention groups performed better on tests than
the control group; at 24 weeks, the dual-intervention group did better
than the program-only group. The study points to the value of cognitive
stimulation to slow the rate of cognitive loss.
The findings are published in the October issue of the
Journal of Neurology, Neurosurgery and Psychiatry.
Full reference
http://www.eurekalert.org/pub_releases/2006-10/uopm-ce102306.htm
Cabernet sauvignon red wine reduces the risk of Alzheimer's disease
A mouse study has found moderate consumption of the red wine Cabernet
Sauvignon significantly reduced Alzheimer’s-type deterioration of
spatial memory function. The Cabernet Sauvignon used contained a very
low content of
resveratrol, 10-fold
lower than the minimal effective concentration shown to promote Aß
clearance in vitro. It is suggested that,
instead, the benefit occurred through promoting non-amyloidogenic
processing of
amyloid precursor protein. The
finding supports epidemiological evidence indicating that moderate wine
consumption (one drink per day for women and two for men) may help
reduce the relative risk for Alzheimer’s.
The study was presented at the annual Society for Neuroscience Meeting
held in Atlanta, Georgia, October 14-18, and will be published in the
November issue of The FASEB Journal.
Full reference
http://www.eurekalert.org/pub_releases/2006-09/tmsh-csr091806.htm
September
New early diagnostic test trialed
A mouse study has used a laser scan of the eyes to accurately
diagnose Alzheimer's well before the disease was evident in the brain.
The study follows on from earlier research revealing that
beta-amyloid protein is
evident in the eyes of Alzheimer’s patients. The test, which is a very
quick and simple procedure, is now in the first stage of experimental
trials in people.
The findings were announced at the annual meeting of the Optical Society
of America.
http://www.sciencentral.com/articles/view.htm3?article_id=218392859
Insulin receptor stops progression of Alzheimer's
Following previous research suggesting Alzheimer's might be a
brain-specific neuroendocrine disorder, or a Type 3 diabetes, a new
study has found that stimulation of
a receptor in the brain that controls insulin responses prevents
several components of neurodegeneration and preserves learning and
memory in rats with induced Alzheimer's disease, raising the possibility
that patients in the very early stages of Alzheimer’s might be
treatable.
The study appeared in the September issue of the
Journal of Alzheimer's Disease.
Full reference
http://www.eurekalert.org/pub_releases/2006-09/l-irs092106.htm
Link between increased weight-loss rate and dementia
Confirming earlier indications, a long-term study of the elderly has
revealed that their average rate of weight loss doubles (from 0.6 pounds
per year to 1.2 pounds per year) in the year before symptoms of
Alzheimer's-type dementia first become detectable. The finding may be
useful as one of several early biomarkers. The study analyzed data on
449 seniors, of whom 125 were eventually diagnosed with mild dementia.
Interestingly, at the beginning of the study, this group weighed about
8lb less on average than the other participants, although the two groups
lost weight at the same rate for four to five years, before weight loss
increased in the group that would eventually be diagnosed with mild
dementia. It is not yet known why there should be this connection
between weight loss and dementia.
The report appeared in the September issue of
Archives of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2006-09/wuso-bdf090806.htm
Two-fold role of Alzheimer’s genes?
The genes responsible for an
inherited form of Alzheimer's
disease — two genes known as
presenilins — are
primarily known for their role as an
enzyme that cleaves
amyloid precursor protein (APP)
to form amyloid ß-peptide, which function has a direct connection to
Alzheimer’s, and consequently has been the focus of attention. However,
new research indicates that these genes also may control the balance of
calcium within cells by acting as a calcium channel, and that the
mutated forms of these genes lose this ability. Given the role that
calcium signaling plays in cognitive function, it may be that this other
role of presenilins is also important in the development of Alzheimer’s.
If so, drugs that restore normal calcium levels might be useful for
treating Alzheimer's disease.
The report appeared in the September 8 issue of
Cell.
Full reference
http://www.eurekalert.org/pub_releases/2006-09/cp-ssa090106.htm
August
Juices may reduce Alzheimer's disease risk
In a large epidemiological study, that followed 1836 Seattle
residents for up to 10 years, it was found that those who drank three or
more servings of fruit and vegetable juices per week had a 76% lower
risk of developing Alzheimer’s disease than those who drank juice less
than once a week. The benefit seemed greatest for those who carried the
so-called “Alzheimer’s gene”.
Previously, researchers suspected that antioxidant vitamins (vitamins C,
E and -carotene) might help protect against Alzheimer's disease, but
this has not been supported in recent clinical studies. Another class of
antioxidant chemicals, polyphenols, are now suspected. Polyphenols
generally exist primarily in the skins of fruits and vegetables and are
particularly abundant in teas, juices and wines.
The report appears in the September issue of The
American Journal of Medicine.
Full reference
http://www.eurekalert.org/pub_releases/2006-08/vumc-jmr082806.htm
http://www.eurekalert.org/pub_releases/2006-08/ehs-ssf082806.htm
High blood sugar linked to MCI and dementia
The first study to investigate the association over time between
blood sugar and the risk of cognitive difficulties involved 1,983
post-menopausal women (mean age 67 years) and found that each 1%
increase in their glycosylated hemoglobin level at the start of the
four-year study period was associated with a 40% increased risk of
developing MCI or dementia four years later.
The glycosylated hemoglobin test gives a more stable measure of blood
sugar level than the standard test, which measures blood sugar it the
time of testing. A result of 7% or less indicates good long-term blood
sugar control. Those with a level of 7% or more were four times more
likely to develop MCI or dementia than women who tested at less than 7%.
The report appeared in the
Journal of Nutrition, Health, and Aging.
Full reference
http://www.eurekalert.org/pub_releases/2006-08/uoc--chb080906.htm
Brain enzyme treatment for Alzheimer's
In a new approach to treating Alzheimer’s, increasing brain levels of
ubiquitin C-terminal hydrolase L1 (Uch-L1) — an
enzyme that helps neurons rid themselves of excess or aberrant
proteins — has restored a great deal of brain activity to mice with
Alzheimer's symptoms. The enzyme Uch-L1 is part of a network that
controls a memory molecule called CREB, which is inhibited by
amyloid beta proteins in
people with Alzheimer's. Uch-L1 is found at reduced levels in the
Alzheimer's brain. As well as improving memory in
genetically engineered mice,
treatments that restored Uch-L1 levels corrected deficits in nerve
transmission both in brain slices treated with amyloid-beta and in
slices taken from
transgenic mice.
The report appeared in the August 25 issue of Cell.
Full reference
http://www.eurekalert.org/pub_releases/2006-08/cp-bet082106.htm
http://www.eurekalert.org/pub_releases/2006-08/cumc-crr082206.htm
Why chances of Alzheimer's increase with age
Experiments with roundworms have revealed two important
proteins that help slow
down the accumulation of
amyloid-beta. HSF-1
breaks apart amyloid and disposes of it — but aging slows HSF-1, so it
can't keep up. DAF-16 helps it out, by clumping extra amyloid together
in a way that makes it less toxic. The finding supports recent research
indicating amyloid clumps, or
plaques, are not the main problem, rather,
smaller amyloid tendrils
inside cells are. The study also explains why aging increases the
likelihood of Alzheimer’s. Most importantly of all, it suggests a new
approach to treating Alzheimer’s.
The report was published online 10 August in
Science Express, and in the 15 September issue of
Science.
Full reference
http://www.msnbc.msn.com/id/14290153/
http://www.boston.com/news/nation/articles/2006/08/11/scientists_find_natural_alzheimers_controls/
July
Predicting dementia risk
A large Scandinavian study has succeeded in calculating middle-aged
people's chances of developing dementia later in life with 70% accuracy.
The study confirms the importance of lifestyle factors. The study
assessed factors such as blood pressure, body fat and cholesterol levels
in 1,400 middle-aged Finns in the 1970s and 1980s, and found that those
who at 40 were obese, or had high blood pressure, or high cholesterol
levels, were twice as more likely to develop dementia by the age of 60.
Having all three of these risk factors increased their chances six-fold.
Other risk factors were age and low education.
The study was published online ahead of print on 3 August in
Lancet Neurology.
Full reference
http://society.guardian.co.uk/health/story/0,,1836464,00.html
Calorie restriction may help prevent Alzheimer's
A mouse study has found that
beta-amyloid peptides can be reduced by restricting calorie intake,
primarily through a low carbohydrate diet. Conversely, a high caloric
intake based on saturated fat was shown to increase levels of
beta-amyloid peptides. This is the first study to suggest that caloric
restriction might inhibit the generation of beta-amyloid peptides, but
there have been a number of studies providing evidence that high
cholesterol, obesity, and other cardiovascular risk factors increase the
likelihood of Alzheimer’s.
The study appeared in the August 4 issue of the
Journal of Biological Chemistry.
Full reference
http://www.sciencedaily.com/releases/2006/06/060614113128.htm
Apples fight memory loss
The study involved adult and old mice (some engineered to develop
Alzheimer's-like symptoms) being fed either a standard diet, a
nutrient-deficient diet, or a nutrient-deficient diet supplemented with
apple juice concentrate. The mice on the apple juice-supplemented diet
showed an increased production of
acetylcholine in their brains and performed significantly better on
maze tests. The amount of consumption was comparable to humans drinking
approximately two 8 oz. glasses of apple juice or eating 2-3 apples a
day. The findings also suggest that the apple-supplemented diet was most
helpful in the framework of an overall healthy diet. Acetylcholine
levels declined in both adult and old mice on the nutrient-deficient
diet.
The study was published in the August issue of the
Journal of Alzheimer's Disease.
Full reference
http://www.sciencedaily.com/releases/2006/08/060801225922.htm
How mental and physical stimulation slows Alzheimer's
A new study reveals how mental and physical activity slows the
cognitive decline seen in Alzheimer’s. In the study, genetically
engineered mice were housed in either standard cages or ones with access
to an enriched environment. After five months, the mice housed in the
enriched environment had fewer
Ab plaques, smaller plaque size, and reduced amyloid angiopathy
compared to mice housed in standard cages. However there were no
differences in the levels of soluble
Ab peptide or the
expression levels of its precursor
protein (APP). Further investigation revealed differences suggesting
that an enriched environment elicits protection via pathways that
prevent Ab accumulation and enhance its clearance. The data confirm that
an environment rich in mental and physical stimulation slows the
progression of Alzheimer-like brain pathology.
The paper appeared in the August issue of the
American Journal of Pathology.
Full reference
http://www.sciencedaily.com/releases/2006/07/060724002331.htm
Weight Loss Precedes Dementia Diagnosis In Women
A study has come out finding that, in women, declining weight
precedes dementia by many years. The retrospective study analyzed the
medical records of 560 patients diagnosed with the onset of dementia
between 1990 and 1994. The patients were matched with 560 controls.
Among the women, average weight increased slightly over the preceding 30
years for the control group, but drifted downwards over the 30 years for
those who developed dementia. The researchers suggest that changes in
the brain interfered somehow with maintenance of body weight. The trend
was not observed in men.
Findings were presented July 16 at the Alzheimer's Association
International Conference on Alzheimer's Disease and Related Disorders in
Madrid, Spain.
http://www.sciencedaily.com/releases/2006/07/060716090233.htm
Elders with dementia can tap into memory stores to give advice
Surprisingly, it appears that the best way to converse with an
Alzheimer’s patient may be to ask them for advice. In two studies,
researchers found that adults with moderate to severe symptoms of
dementia can still be quite coherent and informative when asked for
advice. In the first study, 14 people with early to advanced stages of
dementia were asked about marriage, children and church in a purely
social way, such as "Tell me about your children," and then later were
asked for advice on the same topics, as in, "I'm thinking about having
children. What kind of advice can you give me on that?" Patients were
more coherent, informative and focused on the topic when asked for
advice as opposed to when they were simply asked about their children,
church or marriage. In the second study, six adults with dementia and
six older adults without dementia, were given a booklet of pictures to
guide them in teaching someone a simple recipe. Both groups successfully
taught students to prepare the recipes, although those with dementia did
need more prompting to finish the task.
Findings appeared in the June issue of The
Gerontologist.
Full reference
http://www.eurekalert.org/pub_releases/2006-07/fsu-sew071706.htm
Donezepil slows brain deterioration for some on road to Alzheimer's
According to a new study, the drug
donepezil measurably (but still only slightly) slows the rate of
hippocampal shrinkage in patients with mild cognitive impairment (a
pre-Alzheimer's condition) who carried the
apolipoprotein E4 (APOE 4) gene
variant. The study involved 131 patients with mild cognitive
impairment. For APOE 4 carriers, the rate of
hippocampal
atrophy was 4.5% per year, versus 6.14% in placebo-treated patients.
Rates of shrinkage for cognitively normal people in their late 70s are
approximately 1.4 percent per year. Vitamin E had no significant effect
on atrophy for any patients.
Findings were presented July 17 at the Alzheimer's Association
International Conference on Alzheimer's Disease and Related Disorders in
Madrid, Spain.
http://www.eurekalert.org/pub_releases/2006-07/mc-msd071306.htm
