News reports of research into Alzheimer's disease Jan - June 2008
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.
June
Red grape seeds may help prevent Alzheimer's disease
Research into the nearly 5000 compounds contained in red
wine to reveal the source of the health benefits seen from red wine has revealed
that polyphenols derived from red grape seeds may be useful agents to prevent
or treat Alzheimer's disease. Red grape seeds currently being developed with the
name of Meganatural AZ were found to significantly reduce cognitive
deterioration in genetically engineered mice, by preventing the formation of
amyloid beta. The mice were given the extract before the age at which they
normally develop signs of disease, suggesting the extract may help prevent or
postpone the development of Alzheimer’s. The major polyphenol components in the
grape seed extract product are catechin and epicatechin, which are also abundant
in tea and cocoa. Unlike the polyphenol
resveratrol, which has been shown to
have similar effects, but requires extremely high doses, the catechins appear to
be effective at much lower doses. Further research will of course be needed
before human recommendations can be made.
The study appears in the June 18 issue of The Journal of
Neuroscience. Full
reference
http://www.eurekalert.org/pub_releases/2008-06/tmsh-pnr061708.php
http://www.eurekalert.org/pub_releases/2008-06/sfn-sig061708.php
Gene variation linked to earlier onset of Alzheimer's symptoms
Another genetic variation has been found for Alzheimer’s
disease. Unlike the ‘Alzheimer’s gene’
APOe4, which is linked to the rare
early-onset form, this gene variant is linked to early presentation in people
afflicted with the more common, late-onset form. Rather than increasing the risk
of Alzheimer’s, the gene increases the vulnerability of carriers to the effects
of amyloid plaques, so that symptoms become evident earlier. The gene codes for
the tau protein found in
neurofibrillary tangles. Previous studies have had
inconsistent results, but the new study has dealt with previous difficulties.
The study was reported in the June 10 issue of the
Proceedings of the National Academy of Sciences.
Full reference
http://www.eurekalert.org/pub_releases/2008-06/wuso-gvl060608.php
Low childhood IQ linked to vascular dementia
A study of 173 people from the
Scottish Mental Survey of
1932 who have developed dementia has found that, compared to matched controls,
those with vascular dementia were 40% more likely to have low IQ scores when
they were children than the people who did not develop dementia. This difference
was not true for those with Alzheimer's disease. The findings suggest that low
childhood IQ may act as a risk factor for vascular dementia through vascular
risks rather than the "cognitive reserve" theory.
The results were published online June 25 in Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2008-06/aaon-lci061708.php
More sleep improves cognition in Alzheimer patients with OSA
A study involving 52 participants with an average age of
77.8 years who had Alzheimer disease and obstructive sleep apnea (OSA) has found
that it was increases in total sleep time in those given continuous positive
airway pressure treatment that was associated with improvements in cognition,
rather than improvement in oxygen levels. This suggests that the cognitive
dysfunction associated with OSA in patients with dementia may be in part an
effect of short sleep time.
The findings were presented at SLEEP 2008, the 22nd Annual
Meeting of the Associated Professional Sleep Societies (APSS).
http://www.eurekalert.org/pub_releases/2008-06/aaos-iit050708.php
May
Anti-inflammatory drugs do not improve cognitive function in older adults
Previous studies have suggested that nonsteroidal
anti-inflammatory drugs are associated with a lower risk of
developing Alzheimer’s. A clinical trial involving over 2000 older adults (70+)
with a family history of Alzheimer’s disease compared a twice daily treatment of
200 milligrams of either the NSAID celecoxib, or the NSAID naproxen sodium, or a
placebo. The trial lasted from March 2001 to December 2004. The study found not
only that NSAIDs didn’t improve cognitive function, but that naproxen (but not
celecoxib) was associated with significantly lower cognitive performance.
The study appeared in the July issue of Archives of
Neurology. Full
reference
http://www.eurekalert.org/pub_releases/2008-05/jaaj-add050808.php
Ibuprofen linked to reduced risk of Alzheimer's disease
A very large five-year study of older veterans (55+) has
found that those who used ibuprofen for more than five years were more than 40%
less likely to develop Alzheimer’s disease. Results also showed that the longer
ibuprofen was used, the lower the risk for dementia. Other types of
NSAIDs, such
as indomethacin, were associated with a 25% reduced risk, however others, such
as celecoxib, didn’t show any benefit. There was no obvious connection between
those which were associated with reduced risk and those that weren’t. It may be
that the effect is a product of some other cause.
The study was published in the May 6 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2008-05/aaon-ilt042908.php
Ibuprofen, aspirin, naproxen may be equally effective at reducing Alzheimer's risk
And demonstrating that the jury is still out on
NSAIDs, a
review of six studies has found that people who used NSAIDs had a 23% lower risk
of developing Alzheimer’s disease compared to those who never used NSAIDs. The
risk reduction did not appear to depend upon the type of NSAID taken. However,
the researchers were specifically looking for a difference between those NSAIDs
that lower Aβ1-42 amyloid, which was what they didn’t find — and this
agrees with the finding of the large veteran study. The findings of this study
then may be taken as supporting the view that specific NSAIDs may be of benefit
rather than a particular class of them.
The study was published in the May 28 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2008-05/aaon-ian052008.php
Short arms and legs linked to risk of dementia
Several studies have shown that early life environment
plays an important role in susceptibility to chronic disease later in life. Data
from the Cardiovascular Health Cognition Study (involving 2,798 people for an
average of five years) has now found that women with the shortest arm spans were
1.5 times more likely to develop dementia and Alzheimer’s disease than women
with longer arm spans. For every inch longer a woman’s leg, the risk of dementia
and Alzheimer’s disease was reduced by 16%. In men, only arm span was associated
with a lower risk of dementia. With every increased inch in arm span, men had a
6% decrease in risk of dementia. The association between short limbs and
dementia risk may be due to poor nutrition in early life, which can affect limb
growth (which implies that there should be no such connection if your short
limbs are due to genetics).
The study was published in the May 6 bonus issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2008-05/aaon-saa042908.php
Vaccine prevents Alzheimer's
A vaccine has successfully prevented the development of
amyloid plaques and
tau tangles in the brains of genetically engineered mice.
The vaccinated mice also demonstrated normal learning skills and functioning
memory. There were no major side-effects. Human trials are still a few years
off.
The study appeared in the May issue of Molecular Therapy.
Full reference
http://www.eurekalert.org/pub_releases/2008-05/uorm-vti051908.php
April
Alzheimer's starts earlier for heavy drinkers, smokers
A study of nearly 1000 people diagnosed with possible or
probable Alzheimer’s disease has found that those who were heavy drinkers
developed Alzheimer’s 4.8 years earlier than those who were not, while heavy
smokers developed the disease 2.3 years sooner than people who were not heavy
smokers. Those with the APOE å4 gene developed the disease three years sooner
than those without the gene variant. The risk factors are additive — those with
all three risk factors developed the disease 8.5 years earlier than those with
none of the risk factors.
The research was presented at the American Academy of
Neurology Annual Meeting in Chicago, April 12 – April 19.
http://www.eurekalert.org/pub_releases/2008-04/aaon-ase040208.php
High cholesterol in your 40s increases risk of Alzheimer's disease
A study involving nearly 10,000 people who underwent health
evaluations between 1964 and 1973 when they were between the ages of 40 and 45,
has found that those with total cholesterol levels between 249 and 500
milligrams were one-and-a-half times more likely to develop Alzheimer's disease
than those people with cholesterol levels of less than 198 milligrams. People
with total cholesterol levels of 221 to 248 milligrams were more than
one-and-a-quarter times more likely to develop Alzheimer's disease. High
cholesterol increased risk regardless of midlife diabetes, high blood pressure,
obesity, smoking and late-life stroke.
The research was presented at the American Academy of
Neurology Annual Meeting in Chicago, April 12 – April 19.
http://www.eurekalert.org/pub_releases/2008-04/aaon-hci040208.php
Obesity significantly increases dementia risk
A review of 10 international studies published since 1995, covering just over
37,000 people, has found that obesity increased the relative risk of dementia by
an average of 42% compared with normal weight. Being underweight increased the
risk by 36%. For Alzheimer's Disease and
vascular dementia, specifically,
obesity was an even more significant risk: 80% and 73%, respectively. With
regards to Alzheimer’s, obesity was more likely to be a risk factor for women,
but men were more affected when it came to vascular dementia.
The study appeared in the May issue of Obesity Reviews.
April 2008 news report
http://www.physorg.com/news129376360.html
Diabetes in mid-life linked to increased risk of Alzheimer's disease
A large Swedish study involving over 2000 men has found that
those with low insulin secretion capacity at age 50 were nearly one-and-a-half
times more likely to develop Alzheimer’s disease than people without insulin
problems. The risk remained significant regardless of blood pressure,
cholesterol, body mass index and education, and was strongest in people who did
not have the APOE4 gene.
The study was published online April 9 in Neurology.
April 2008 news report
http://www.eurekalert.org/pub_releases/2008-04/aaon-dim040108.php
Significant dementia risk attributable to small blood vessel damage
Autopsy data of 221 men and women found that the brains of
one-third of individuals who had dementia before death showed evidence of small,
cumulative blood vessel damage that can arise from hypertension or diabetes.
The findings were reported at the
annual meeting of the American Society for Biochemistry and Molecular Biology,
April 5-9, San Diego.
http://www.eurekalert.org/pub_releases/2008-04/asfb-sdr040208.php
Link between diabetes and Alzheimer's disease
A mouse study has shed light on the connection between
diabetes and Alzheimer’s. It appears that the elevated blood glucose levels
characteristic of diabetes interacts with
beta amyloid in a way damaging to
blood vessels in the brain.
The study was published online 26 March in Neurobiology of
Aging. April 2008
news report
http://www.eurekalert.org/pub_releases/2008-04/si-ssl043008.php
Size of hippocampus affects dementia-related memory loss
Autopsies have found that those who had sharp memories and
thinking skills at the time of death, despite a high amount of Alzheimer’s
plaques, had a significantly bigger
hippocampus than those with the same amount
of plaques, and a diagnosis of Alzheimer’s disease before death.
The research was presented at the American Academy of
Neurology Annual Meeting in Chicago, April 12 – April 19.
http://www.eurekalert.org/pub_releases/2008-04/aaon-hbi040208.php
Vitamin E may help Alzheimer's patients live longer
A study of 847 Alzheimer's patients has found that those
who took 1,000 international units of vitamin E twice a day, were 26% less
likely to die over a five-year period than people who didn't take vitamin E. It
also appears that taking vitamin E plus a
cholinesterase inhibitor may be more beneficial than
taking either agent alone.
The research was presented at the American Academy of
Neurology Annual Meeting in Chicago, April 12 – April 19.
http://www.eurekalert.org/pub_releases/2008-04/aaon-vem040208.php
Alzheimer's vaccine clears plaque but doesn't improve memory
A two-year canine study has revealed that although a
promising vaccine being tested for Alzheimer's disease clears
beta-amyloid
plaques from the brain, it doesn’t seem to help restore lost learning and memory
abilities. Autopsies showed that although plaques had been cleared from multiple
brain regions, damaged neurons remained. The findings suggest that simply
treating beta-amyloid plaques may have only limited clinical benefit if started
after there is significant plaque growth, and a combination of vaccination with
other therapies aimed at repairing damaged neurons may be best.
The results appeared in the April 2 issue of the Journal of
Neuroscience. April
2008 news report
http://www.eurekalert.org/pub_releases/2008-04/uoc--avc040408.php
Depression a risk factor for Alzheimer's disease
Previous studies have found higher levels of depressive
symptoms among patients with Alzheimer’s disease or mild cognitive impairment.
Now the Religious Orders Study reveals that although those with more symptoms of
depression at the beginning of the study (in 1994) were more likely to develop
Alzheimer’s disease, those who developed Alzheimer’s disease showed no increase
in depressive symptoms in the years before the diagnosis was made. This suggests
that depression is a risk factor for dementia rather than a consequence.
The report was published in the April issue of Archives of
General Psychiatry. April
2008 news report
http://www.eurekalert.org/pub_releases/2008-04/jaaj-sod040308.php
Tarenflurbil slows decline of mild Alzheimer's patients
A trial of 210 patients with mild to moderate Alzheimer’s
has found that those with mild Alzheimer’s who received 800mg of tarenflurbil
twice a day for a year experienced a rate of decline 46% lower than placebo
patients in the activities of daily living scale, and a 36% reduction in the
pace of decline in global function. In those with moderate Alzheimer’s, neither
400mg or 800mg of tarenflurbil had a significant effect, and indeed impacted
negatively on a third measure of global function. Patients with mild Alzheimer’s
who took 800mg for 24 months had lower rates of decline for all three primary
outcomes than those who took it for a shorter period.
The findings appear online ahead of the June issue of The
Lancet Neurology. April
2008 news report
http://www.eurekalert.org/pub_releases/2008-04/l-tsd042808.php
March
Paradoxical finding may shed new light on memory loss
Following a previous study, in which genetically engineered
mice were prevented from getting Alzheimer’s by blocking a single site of
cleavage of amyloid precursor protein (APP), studies of brain tissue from
Alzheimer’s patients were found to have clearly more of this cleavage process
than people of the same age who do not have the disease. However, much younger
people without Alzheimer’s displayed as much as ten times the amount of the same
cleavage event. The researchers now believe that normal memory loss is
hyper-activated in Alzheimer’s, pointing to Alzheimer’s as a disorder affecting
the plasticity, the ability to make and break memories, of the brain. Rather
than the problem lying with the buildup of
A-beta, the researchers suggest the
problem lies in the downstream signaling of A-beta.
The study was published in the February issue of the
Journal of Alzheimer’s Disease.
Full reference
http://www.eurekalert.org/pub_releases/2008-03/ip-paf031208.php
Potential new drug target identified
A mouse study has successfully reduced the production of
beta-amyloid peptides, and improved memory. These peptides are produced when
enzymes cut APP at two places, called the
beta-secretase and
gamma-secretase
sites. Previous research has focused on a mutant beta-secretase sequence only
seen in one extended family of patients, the so-called Swedish mutation. The new
study identifies a different enzyme, called Cathepsin B (CatB), which works to
cut the normal beta-secretase site in more than 99% of patients with
Alzheimer’s. Two compounds that inhibit CatB were successfully tested, producing
great improvement in memory, as well as reduced brain levels of beta amyloid.
The study was published in the March 21 edition of the
Journal of Biological Chemistry.
Full reference
http://www.eurekalert.org/pub_releases/2008-03/uoc--pad031108.php
Study validates Pittsburgh Compound-B in identifying Alzheimer's disease toxins
Previous research demonstrating that Pittsburgh Compound-B
(PiB) binds to beta-amyloid deposits has involved only the autopsied brains of
patients afflicted with Alzheimer’s. A new study correlated PiB-identified
beta-amyloid deposits in a living patient with post-mortem autopsy results 10
months later, confirming that PiB allows accurate assessment of the amount of
beta-amyloid plaques in brains of people afflicted with Alzheimer’s. A further
study of the autopsied brains of 27 other patients with confirmed Alzheimer’s
confirmed that PiB binds almost exclusively to beta-amyloid.
The findings were reported online March 12 in Brain.
Full reference
Full text at
http://brain.oxfordjournals.org/cgi/content/abstract/awn016v1
http://www.eurekalert.org/pub_releases/2008-03/uops-svp032608.php
Results of caregiver survey
Results from the third annual Alzheimer’s Foundation of
America Investigating Caregivers’ Attitudes and Needs Survey found that about
three in five caregivers say their children aged 8 to 21 are involved in caring
for a loved one with Alzheimer’s. Of the caregivers who feel they do a good job
balancing the care of their loved ones with Alzheimer’s disease and children
under 21, more than one-third (36%) specifically cited support from children as
a contributor to their success. Additionally, nearly two-thirds (63%) would like
more information about how to help their children cope when a loved one is
diagnosed with Alzheimer’s. Caregivers of sufferers whose diagnosis was delayed
for a year or more say the delay was most often due to lack of caregiver
familiarity with symptoms or insufficient knowledge about Alzheimer’s.
Additional key survey findings can be found at
www.alzfdn.org.
http://www.eurekalert.org/pub_releases/2008-03/fi-nad032508.php
Larger belly in mid-life increases risk of dementia
A study involving 6,583 people measured abdominal fat at
age 40 to 45, and dementia occurrence some 36 years later. Those with the
highest amount of abdominal fat were found to be nearly three times more likely
to develop dementia than those with the lowest amount of abdominal fat. Having a
large abdomen increased the risk of dementia regardless of overall weight and
existing health conditions, although being obese as well did increase the risk.
Those more likely to have abdominal obesity, were women, non-whites, smokers,
people with high blood pressure, high cholesterol or diabetes, and those with
less than a high school level of education.
The study was published online March 26 in Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2008-03/aaon-lbi031808.php
PET's targeted imaging may lead to earlier diagnosis of dementia
Use of PET imaging with the radiotracer fluorodeoxyglucose
(FDG) has allowed researchers to classify different types of dementia
(Alzheimer’s, frontotemporal dementia, and dementia with Lewy bodies) with very
high rates of success (94%).
The study was reported in the March issue of the Journal of
Nuclear Medicine.
Full reference
http://www.eurekalert.org/pub_releases/2008-03/sonm-pti030508.php
February
Vitamin E or C does not reduce risk of dementia or Alzheimer's
A five-year study involving nearly 3000 people has found
that use of Vitamin C or E or both was not associated with a reduced risk of
developing dementia or Alzheimer’s.
The study was published in the February issue of the
Journal of the American Geriatrics Society.
Full reference
http://www.eurekalert.org/pub_releases/2008-02/bpl-veo020408.php
PLMI factor in sleep disturbance for dementia patients
A study of 102 people diagnosed with both cognitive
impairment and sleep disturbance (average nightly sleep of seven or less hours
and daytime sleep of 30 minutes or longer) found that periodic leg movement
disorder (a condition that causes people to jerk and kick their legs every 20 to
40 seconds during sleep) was predictive of reduced total sleep time in older
adults with Alzheimer disease and related dementias. Given that sleep
disturbance in persons with dementia is a highly prevalent and disabling
symptom, and sedative-hypnotics are not recommended, this finding is important
because it suggests treatment of periodic leg movements may be beneficial.
The study was published in the February 1 issue of SLEEP.
Full reference
http://www.eurekalert.org/pub_releases/2008-02/aaos-ppt012808.php
Computers better at diagnosing Alzheimer's
A new method has been developed that allows a standard
computer to spot the differences between brain scans from patients with proven
Alzheimer’s disease and people with no signs of the disease at all. The accuracy
is better than the 86% correct diagnostic rate of best clinical practice. The
method was also better at distinguishing Alzheimer’s from
fronto-temporal
dementia. The findings may help ensure that patients are diagnosed earlier,
increasing treatment options.
The research was published in the March issue of Brain.
Full reference
http://www.eurekalert.org/pub_releases/2008-02/wt-ccb022108.php
January
Mental and physical exercise delays dementia
A study using genetically engineered mice has found
providing the mice with an enriched environment that enhanced their mental and
physical stimulation improved performance on memory tests at an early stage of
Huntington's disease, when memory impairment has begun. Specific molecular changes were
also observed at the synapses in the
hippocampus. Those without increased mental
and physical activity showed decreased levels of specific
proteins that are
expressed at the synapse, but those exposed to stimulation didn’t. The finding
offers hope for slowing the progression of the disease, as well as other
dementias.
The report appeared online November 24 in the Neurobiology
of Disease. Full reference
http://www.eurekalert.org/pub_releases/2008-01/ra-map012308.php
Driving proves potentially hazardous for people with early Alzheimer's
A study of 128 older drivers, including 84 with
early Alzheimer’s and 44 age-matched controls, has confirmed previous
reports of potentially hazardous driving in persons with early Alzheimer’s, but
also indicates that some individuals with very mild dementia can continue to
drive safety for extended periods of time. The study looked at driving abilities
through self-reports, family reports and a standardized road test, and followed
the participants every six months over two to three years. It found that people
with early Alzheimer’s experienced more accidents and performed more poorly on
road tests when compared to participants without cognitive impairments, but
those with mild dementia were nearly four times more likely to fail a road test
than those with very mild dementia, indicating that people with very mild
dementia may be able to drive safely for longer periods of time. Both increased
age and lower education increased the odds of failing a road test. However, the
frequency of accidents did decline during the study, suggesting that a regular
driving assessment program may increase awareness among the driver and
caregivers.
The study was published online January 23 in Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2008-01/l-dpp012208.php
Portable device quickly detects early Alzheimer's
A new device may allow patients to take a brief,
inexpensive test that could be administered as part of a routine yearly checkup
at a doctor’s office to detect mild cognitive impairment (MCI) — often the
earliest stage of Alzheimer’s. The device, called DETECT, takes about ten
minutes to run through a battery of visual and auditory stimuli such as pictures
and words that assess cognitive abilities relative to age, gauging reaction time
and memory capabilities. Its software can track cognitive capabilities year to
year during annual appointments. Moreover, because the device blocks outside
sound and light from the patient’s environment, it can be administered in
virtually any setting, providing more consistent results. Preliminary analysis
gives the test similar accuracy to the 90-minute “Gold Standard” pen and paper
test. The device is expected to be commercialized later this year.
http://www.eurekalert.org/pub_releases/2008-01/giot-pdq011608.php
Memantine works differently than thought
New research shows that the drug memantine, praised as
"the first and only representative of a new class of Alzheimer drugs", in fact
works similar to other existing compounds, and although the data do confirm that
memantine shows promising aspects for the treatment of Alzheimer’s, this is only
in a narrow concentration range. Its complex pharmacological profile requires
careful considerations concerning suitable doses and suitable patient groups.
The study was published in the December issue of the Journal of Alzheimer's Disease.
Full reference
http://www.eurekalert.org/pub_releases/2008-01/ip-maa011008.php
Cholesterol-lowering drugs may not prevent Alzheimer's disease
Research on the protective benefit or otherwise of taking
statins has been contradictory to date. Now new results from the long-running
Religious Orders Study has come down on the side of no benefit. The study found
no relation between statin use and Alzheimer’s, and no association between
taking statins and a slower cognitive decline among older people.
The report was published online January 16 in Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2008-01/aaon-cdm010808.php
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