News reports of research into Alzheimer's disease July - December 2007
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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
Walking and moderate exercise help prevent dementia
A four-year study involving 749 older adults has found
that the top one-third of participants who exerted the most energy in moderate
activities such as walking were significantly less likely to develop
vascular
dementia than those people in the bottom one-third of the group. Contrary to
some reports, no such association was found with Alzheimer’s disease.
The study was published in the December 19 issue of
Neurology. Full
reference
http://www.eurekalert.org/pub_releases/2007-12/aaon-wam121107.php
Why fish oil is good for you
Confirming previous research indicating that fish oil
helps delay or prevent Alzheimer’s, a new study shows why. The study reveals
that the omega-3 fatty acid DHA found in fish oil increases the production of
LR11, a protein that is found at reduced levels in Alzheimer's patients and
which is known to destroy the protein that forms the "plaques" associated with
the disease. The study looked at both rodent brains and human brain cells. Still
to be determined is what the optimal dose should be.
The report appeared in the December 26 issue of the Journal of Neuroscience. Full
reference
http://www.eurekalert.org/pub_releases/2007-12/uoc--wfo122107.php
November
Healthy diet lowers risk of dementia
A very large study of older adults has found that those
who regularly consumed omega-3 rich oils, such as canola oil, flaxseed oil and
walnut oil, reduced their risk of dementia by 60% compared to people who did not
regularly consume such oils. People who ate fruits and vegetables daily also
reduced their risk of dementia by 30% compared to those who didn’t regularly eat
fruits and vegetables. Additionally, those who ate fish at least once a week had
a 35% lower risk of Alzheimer’s and a 40% lower risk of dementia, but only if
they did not carry ApoE4 gene. And finally, the study found those who didn’t
have the gene but consumed an unbalanced diet characterized by regular use of
omega-6 rich oils, but not omega-3 rich oils or fish, were twice as likely to
develop dementia compared to those who didn’t eat omega-6 rich oils, which
include sunflower or grape seed oil. The study did not find any association
between consuming corn oil, peanut oil, lard, meat or wine and lowering risk of
dementia.
The study was published in the November 13 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-11/aaon-efo110607.php
High blood pressure or irregular heartbeat linked to Alzheimer's disease progression
A study of 135
men and women newly diagnosed with Alzheimer’s found that those with high blood
pressure at the time of diagnosis showed a rate of memory loss roughly 100%
faster than those with normal blood pressure, and those with atrial fibrillation
(an irregular heartbeat) showed a rate of memory decline that was 75% faster
than those with normal heartbeats. The findings suggest that treating these
conditions may also slow memory loss in Alzheimer’s sufferers.
The results were
published in the November 6 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-11/jhmi-hbp103007.php
http://www.eurekalert.org/pub_releases/2007-11/aaon-hbp103007.php
Drugs may not delay onset of dementia
A review of six
clinical trials that had addressed the use of
cholinesterase inhibitors (donepezil,
rivastigmine and
galantamine) with
MCI patients has found that in none of the
trials did the use of the drugs significantly reduce the rate of progression
from MCI to dementia.
Full text available at
http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.0040338
The report appeared in the open access journal PLOS Medicine.
Full reference
http://www.eurekalert.org/pub_releases/2007-11/plos-dmn112207.php
Maternal inheritance more importance than paternal for Alzheimer's risk?
In an intriguing
preliminary study comparing brain metabolism among cognitively normal people who
have a father, a mother, or no relatives with Alzheimer’s disease, researchers
have found that only those with an affected mother have reduced brain metabolism
in the same brain regions as Alzheimer’s patients.
The study was
published in the November 27 issue of Proceedings of the National
Academy of Sciences.
Full reference
http://www.eurekalert.org/pub_releases/2007-11/nyum-aml110607.php
October
National study of dementia prevalence
A study using
data from 856 men and women who participated in the nationally representative
Aging, Demographics and Memory Study estimates one in seven or 13.9% of the
American population aged 71 and older, have some form of dementia. About 70% of
those, or 9.7% of the population, have Alzheimer’s, and 17.4% of them have
vascular dementia. As expected, the prevalence of dementia increased
dramatically with age, from 5% of those aged 71 to 79 to 37.4% of those age 90
and older. With increasing age, Alzheimer’s disease accounted for progressively
more of the dementia cases, so that in the 90+ age group, it comprised 79.5% of
dementia cases, compared to 46.7% among those in their 70s. There was no
difference between genders when corrected for education and age. Previous
national estimates of dementia prevalence have been extrapolated from regional
samples, and were generally significantly lower.
The findings were
published in the November issue of Neuroepidemiology.
Full reference
Full text available at:
http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=109998&Ausgabe=233821&ProduktNr=224263&filename=109998.pdf
http://www.eurekalert.org/pub_releases/2007-10/uom-oi7103007.php
Effect of cognitive reserve on dementia confirmed
Another study has
come out confirming that people with more years of education begin to lose their
memory later than those with less education, but decline faster once it begins.
Researchers note that since the participants were born between 1894 and 1908,
their life experiences and education may not represent that of people entering
the study age range today.
The findings were
published in the October 23 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-10/aeco-mep101707.php
Not finishing high school may lead to memory problems
A long-running
Finnish study has found that compared with people with five or less years of
education, those with six to eight years had a 40% lower risk of developing
dementia and those with nine or more years had an 80% lower risk. Generally
speaking, people with low education levels seemed to lead unhealthier
lifestyles, but the association remained after lifestyle choices and
characteristics such as income, occupation, physical activity and smoking had
been taken into account.
The study was published in the October 2 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-10/aaon-nfh092507.php
Anti-hypertensive drug may help prevent and treat Alzheimer's disease
A review of more
than 1,500 drugs commercially available for treatment of other disorders, to
determine their potential value in treating Alzheimer's disease, identified 7
out of 55 candidate drugs commonly prescribed for the treatment of hypertension
as capable of significantly preventing
beta-amyloid production. Only one of
these drugs — Valsartan — was shown to have a marked in vitro effect, and this
drug has now been shown to reduce the severity of Alzheimer’s in
genetically
engineered mice.
The research was
published online ahead of print October 25 in The Journal of Clinical
Investigation.
Full reference
Full text available at:
http://www.jci.org/cgi/reprint/117/11/3393
http://www.eurekalert.org/pub_releases/2007-10/tmsh-adm102307.php
http://www.eurekalert.org/pub_releases/2007-10/joci-dtl101807.php
Familial link between Parkinson's and dementia
A study of relatives of patients with Parkinson’s disease
provides evidence that relatives of patients with Parkinson’s disease (primarily
younger age at onset Parkinson’s) have an increased risk of cognitive impairment
or dementia.
The report appeared in the October issue of Archives of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-10/jaaj-rop100407.php
September
Mediterranean diet may help Alzheimer's patients live longer
A study of 192 people with Alzheimer's
disease has found that those who most closely followed a Mediterranean diet were
76% less likely to die during the 4 ½ year study period compared to those who
followed the diet the least. A previous study by the same researchers found that
healthy people who eat a Mediterranean diet lowered their risk of developing
Alzheimer's disease. The Mediterranean diet includes a high intake of
vegetables, legumes, fruits, cereals, fish, monounsaturated fatty acids; a low
intake of saturated fatty acids, dairy products, meat and poultry; and a mild to moderate
amount of alcohol.
The study was published in the September
11 issue of Neurology.
Full reference
http://www.sciencedaily.com/releases/2007/09/ 070910162411.htm
http://www.eurekalert.org/pub_releases/2007-09/aaon-mdm090407.php
Smokers are more likely to develop dementia
A seven-year
study of some 7,000 people age 55 and older found that those who were current
smokers at the time of the study were 50% more likely to develop dementia than
people who had never smoked or past smokers. Smoking did not increase the risk
for those with the Alzheimer’s gene apolipoprotein E4. Current smokers without
the gene were nearly 70% more likely to develop Alzheimer’s than nonsmokers or
past smokers without the gene.
The study was published in the September 4 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-09/aaon-sam082807.php
Support for view of Alzheimer's as form of diabetes
Research in the
last few years has raised the possibility that Alzheimer’s memory loss could be
due to a third form of diabetes. A new study clarifies the connection between
insulin and Alzheimer’s. It seems that the toxic protein
ADDL, found in the
brains of individuals with Alzheimer’s, removes insulin receptors from nerve
cells, rendering those neurons insulin resistant. The findings
suggest that some existing drugs now used to treat diabetic patients may be
useful for Alzheimer’s treatment.
The findings were published online August 24 in FASEB Journal.
Full reference
http://www.eurekalert.org/pub_releases/2007-09/nu-dst092607.php
Misconceptions about Alzheimer's common
A recent survey
of nearly 1200 people has found a high degree of misconceptions about
Alzheimer’s in America. Half the respondents were unaware that anything could be
done to maintain cognitive functioning and reduce Alzheimer's risk. Although
there were no significant differences among races in the level of concern about
getting Alzheimer's, many more blacks and Hispanics than whites responded that
they believe that Alzheimer's is a normal part of aging. However, blacks and
Hispanics were also more likely than whites to report changing their diet or
lifestyle to avoid developing Alzheimer's.
The findings were reported in the July/September issue of Alzheimer Disease &
Associated Disorders.
Full reference
http://www.eurekalert.org/pub_releases/2007-09/uom-maa091807.php
August
High stress and genetic risk factor lead to increased memory decline
A study involving
91 older, healthy subjects (mean age 78.8 years) has found that those low on
stress (low levels in cortisol) or without the APOE-ε4 gene performed better on
memory measures than those with high stress or those with the APOE-ε4
gene. Those who had the gene and had high stress levels showed the greatest
memory impairment.
The study was
published in the September 1st issue of Biological Psychiatry.
Full reference
http://www.eurekalert.org/pub_releases/2007-08/e-naf082707.php
Women lose weight at least a decade before developing dementia
Another study has
come out associating weight loss with later dementia. The study found that women
who later developed dementia started losing weight up to 20 years before the
disease was diagnosed. On average, those with dementia weighed 12 pounds less
than those without the disease the year the disease was diagnosed. The
association may be related to a loss in the sense of smell, and increasing
apathy. The association was not found with men, probably because older men were
less likely to be preparing their own food. The findings do of course conflict
with others suggesting that obesity in middle-age may be a risk factor for
dementia. More research is needed to clarify the situation.
The study was
published in the August 21 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-08/aaon-wlw081407.php
July
Drug improves symptoms of severe Alzheimer's disease
A six-month study involving 343 people with severe
Alzheimer’s disease has found that donepezil, a drug used to treat mild to
moderate Alzheimer’s, stabilized or improved cognitive function in 63% of those
taking donepezil compared to 39% of those taking placebo. Compared to the
placebo group, those taking donepezil showed improvement in memory, language,
attention, and recognizing one’s name. The donepezil group also showed less of a
decline in social interaction, skills needed to complete a jigsaw puzzle, and
arranging sentences compared to the placebo group.
The study was published in the July 31 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-07/aaon-dis072407.php
New gene mutation identified in frontotemporal dementia
A family in southern Italy has enabled researchers to
identify a gene mutation that increases the chances of frontotemporal dementia.
The gene is located on chromosome 17 and is named progranulin. The mutation
leads to a loss of progranulin, a protein growth factor that helps brain cells
survive. Production of too much progranulin has been associated with cancer. The
genetic form of the disease is rare, however.
The study was published in the July 10 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-07/aaon-ngm062907.php
New diagnostic criteria for Alzheimer's disease
An international group of Alzheimer’s disease (AD) experts
have proposed new diagnostic criteria for Alzheimer’s. The existing criteria
were published in 1984. To meet the new criteria for probable AD, patients must
show progressive memory loss over more than six months, plus at least one or
more of the supportive biomarker criteria. These include: atrophy in a
particular part of the brain shown by MRI, abnormal biomarker proteins in the
cerebrospinal fluid, a specific pattern on PET of the brain, and a genetic
mutation for AD within the immediate family.
The proposal was published early Online and in the August
edition of The Lancet Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-07/l-ndc070607.php
