News reports of research into Alzheimer's disease July - December 2002
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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 study counters previous research linking intake of dietary fat with increased risk of dementia
Previous studies suggesting that fat may be
involved in the development of dementia and Alzheimer’s disease have
been contradicted by a new study involving over 5,000 elderly people
over a period of six years. The study found no correlation between
fat and cholesterol intake and risk of dementia, and no evidence for
a reduction in risk for those taking cholesterol lowering
medication.
The study was reported in the December 24 issue of
Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2002-12/aaon-nsc121602.htm
November 2002
Life expectancy following diagnosis of Alzheimer’s depends on age at diagnosis
A new study reveals that the life span of people with
Alzheimer's disease depends greatly on the age of the person when Alzheimer's
disease is diagnosed. The study indicates that the median survival of patients
with Alzheimer's disease could range from 8.3 years for those diagnosed at age
65 to 3.4 years for those diagnosed at age 90. There were no significant
differences between men and women. The average length of time between the onset
of symptoms and the diagnosis of Alzheimer's was 2.8 years.
The findings are published in the November 18 edition of
Archives of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2002-11/jhub-lef111502.htm
Animal studies suggest why estrogen can't help after dementia has developed
Research with rats suggests that nerve cells in the
brain called cholinergic neurons are needed for estrogen to help learning and
memory. This suggests why starting estrogen after dementia has developed is
ineffective.
The report appeared in the November issue of Hormones and
Behavior.
Full reference
http://www.eurekalert.org/pub_releases/2002-11/uopm-asp110502.htm
Drinking wine may lower risk of dementia
Researchers in Copenhagen have followed up an analysis of
drinking patterns for wine, beer and liquor
of 1,709 people in the 1970s with an assessment of dementia in
the 1990s, when participants were age 65 or older. 83 of the
participants had developed dementia. Their alcohol intake was
compared to that of those who did not develop dementia. It was
found that those who drank wine occasionally had a lower risk of
developing dementia, including Alzheimer's disease. Those who
drank wine every day were no more or less likely to develop
dementia than those who drank it less often. The study also
found that occasional beer drinking was associated with an
increased risk of developing dementia. It is important to note
that eating habits were not investigated, and research suggests
that wine drinkers may have better dietary habits than beer and
liquor drinkers.
The study was published in the November 12 issue of
Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2002-11/aaon-dwm110702.htm
PET scans can help early diagnosis of Alzheimer's
Early diagnosis of Alzheimer’s is becoming more and more important, with the
arrival of drugs and therapies which can help slow the progression of the
disease, if caught early. A new study reveals that PET scans may be able to
identify Alzheimer’s, and distinguish it from other dementias.
Initial results were presented recently at the International Conference on
Alzheimer's Disease and Related Disorders.
http://www.eurekalert.org/pub_releases/2002-11/uomh-sit110102.htm
October 2002
Memory training may help some Alzheimer's patients
Following anecdotal "success stories" of
memory training provided by rehabilitation experts, researchers
in London conducted a controlled study to see whether such
training could be standardized for a larger group of people, and
whether the benefits of training endured. The study involved 12
participants with probable Alzheimer's Disease (AD) at the
minimal or mild stage, when they still had some capacity for
learning. The researchers then trained participants to remember
the names of people whom they had difficulty naming from a set
of 12 photos that included people in their social network and
famous people. They used such memory aids as mnemonic devices,
which use the image to jog memory through some kind of
meaningful association; "vanishing cues," a method in which
participants fill in more and more letters in the person's name,
until they can recall that name without any help; and "expanding
rehearsal," in which people test themselves on what they've
learned, in spaced intervals over time. All training minimized
the chance of errors, which helped to reduce distress and raise
confidence. By training participants' memory for just half of
their photo sets, researchers were able to compare memory
training with no training, for each participant. Participants
learned the face-name association at the rate of one per week,
adding each new pair to their practice until they worked at all
six pairs. They continued practicing until a one-month follow-up
test of the face-name pairs. Testing was repeated at three, six
and 12 months. The memory training produced a statistically
significant improvement in group performance on free recall of
trained items. Participants kept their memory gains six months
after training, and scores remained above baseline levels after
12 months -- even without further practice. Not all participants
benefited from the training. Further research is needed to
discover what distinguishes those who benefited from those who
didn’t. One factor that was found, was that those who were more
aware of their memory problems were more likely to respond well
to memory training.
The report appeared in the October issue of
Neuropsychology.
Full reference
http://www.eurekalert.org/pub_releases/2002-10/apa-mtm101502.htm
Full text of the article is available from:
http://www.apa.org/journals/neu/press_releases/october_2002/neu164538.html
Long-term ERT in postmenopausal women with Alzheimer's may worsen memory
A study using female rats investigated the interaction
of two conditions known to exist within the brains of female Alzheimer's
patients: 1) the presence of chronic neuroinflammation, and 2) having too much
or not enough estrogen. They found that rats who had their ovaries removed (to
model the condition of post-menopausal women) performed more poorly on a water
maze task when they had chronic brain inflammation OR long-term estrogen
replacement therapy. Most significantly, those who had both conditions performed
much more poorly – beyond what would be expected by either condition alone. That
such results extend to postmenopausal women is supported by a 2000 study
involving a long term, placebo-controlled study that examined the effects of
estrogen replacement therapy on cognitive function in women with mild to
moderate Alzheimer's. The effects of ERT were initially beneficial, but the
performance of women receiving sustained ERT declined more than that of women
receiving the placebo treatment. The results of these studies suggest that
postmenopausal women with Alzheimer's disease who undergo long-term estrogen
replacement therapy may make their memory loss worse.
The study was reported in the October issue of Behavioral
Neuroscience.Full
reference
http://www.eurekalert.org/pub_releases/2002-10/apa-lei102202.htm
Full text of the article is available at
http://www.apa.org/journals/bne/press_releases/october_2002/bne1165902.html.
Moderately high homocysteine linked to Alzheimer’s risk
A study of 83 Alzheimer’s patients, 78 patients
with vascular dementia, 64 stroke patients, and 71 healthy controls, found that
elevated levels of homocysteine were associated with a more than five-fold
increase in the risk for stroke, a nearly five-fold risk for vascualr dementia,
and almost triple the risk for Alzheimer's disease. High blood levels of
homocysteine have been found to be associated with an increased heart attack
risk in several studies. High levels of homocysteine have been found to be
associated with deficiencies in vitamin B12 and folate, and also with smoking.
The report appeared in the October issue of Stroke.Full
reference
http://www.eurekalert.org/pub_releases/2002-10/aha-mhh092602.htm
A nicotine by-product implicated in Alzheimer’s
A previously unrecognized chemical process has been
discovered, by which a chemical called nornicotine, naturally present in tobacco
and produced as a metabolite of nicotine, permanently and irreversibly modifies
proteins in the body. These modified proteins interact with other chemicals in
the body to form a variety of compounds known as advanced glycation endproducts.
Advanced glycation endproducts have previously been implicated in numerous
diseases including diabetes, cancer, atherosclerosis, and Alzheimer’s disease.
The study was reported in the October 28, 2002 online edition of the
Proceedings of the National Academy of Sciences.Full
reference
http://www.eurekalert.org/pub_releases/2002-10/sri-aka102402.htm
Eating fish cuts risk of dementia
Using data from a French epidemiological study of
cognitive and functional aging, researchers found that those who ate fish or
seafood at least once a week had a significantly lower risk of being diagnosed
as having dementia (including Alzheimer’s) over the seven years follow-up. This
confirms earlier findings from the Rotterdam Study, which had a much shorter
follow-up (a mean of 2.1 years). There was an association between level of
education and diet which partly, but not completely, explains this. It does
appear that this is a benefit from eating fish / seafood, possibly from the
fatty acids found in fish oils. There was no significant association between
meat consumption and risk of dementia.
The study appeared in the October 26 issue of the British
Medical Journal
(BMJ).Full reference
http://www.eurekalert.org/pub_releases/2002-10/bmj-efc102302.htm
Value of PET scans in diagnosing Alzheimer’s
A new study has measured the advantage of early diagnosis of
Alzheimer’s using PET scanning. The study
compared the use of two strategies for diagnosing Alzheimer's:
clinical evaluation using the American Academy of Neurology
(AAN) 2001 recommendations, and the same with the addition of a
PET scan. They concluded that, although both approaches
accurately diagnosed most Alzheimer's patients, the appropriate
use of PET reduced erroneous diagnoses by half. A review of the
literature suggested conventional methods would falsely
attribute symptoms to early Alzheimer's in 23 cases out of 100,
and overlook eight cases. Analysis suggested that incorporating
PET scans would have prevented 11 of the 23 false positives and
five of the eight false negatives. The researchers estimated
that PET could cut unnecessary drug therapy by half (48%) and
reduce months in a nursing home by 62%.
The study was reported in the Nov/Dec issue of
Molecular Imaging and Biology.
Full reference
http://www.eurekalert.org/pub_releases/2002-10/uoc--uss100402.htm
Can Alzheimer's disease be slowed by shunting cerebrospinal fluid?
A pilot study has tested the hypothesis that improving cerebrospinal fluid (CSF)
turnover will slow or stop the progression of dementia in people with
Alzheimer's disease. CSF shunting for dementia, described in 1969, was largely
abandoned due to mixed clinical results and an unacceptably high incidence of
adverse events. However recent clinical studies in which CSF shunting was used
to treat patients with symptomatic hydrocephalus demonstrated a coincidental
lack of cognitive decline in patients who also had Alzheimer's dementia. A pilot
study has found Alzheimer's patients who were shunted experienced relative
stability while the control group demonstrated a fairly robust decline in
cognitive function over the 12 months of the study. A larger, multi-center,
controlled clinical trial is now underway.
The study appeared in the October 22 issue of Neurology.
Full
reference
http://www.eurekalert.org/pub_releases/2002-10/aaon-cad101502.htm
September 2002
Regular long-term use of aspirin may reduce the risk of Alzheimer’s
A large-scale study of 5,092 older adults has found that
regular use of aspirin
and other non-steroidal anti-inflammatory drugs may reduce the
incidence of dementia in elderly people, but only when taken for
more than two years, and provided the use occurred well before
the onset of dementia.
The study was reported in the September 24 issue of
Neurology.Full
reference
http://www.eurekalert.org/pub_releases/2002-09/aaon-get091702.htm
