|
|
- Association of mid-life consumption of
tofu with late life cognitive impairment and dementia: the Honolulu-Asia
Aging Study.
- White L, Petrovich H, Ross GW, Masaki K.
- Fifth International Conference on Alzheimer's
Disease, #487, 27 July 1996, Osaka, Japan.
- Abstract
- Tofu and other soybean foods contain isoflavones
- three ringed molecules bearing structural resemblance to steroidal
hormones and having significant estrogen agonistic or antagonistic
activities apparently related to their interactions with estrogen
receptors and/or with enzymes involved in estrogen metabolism.
- There is evidence suggesting that estrogens modulate
neural and synaptic plasticity during aging. Male neurons have
both estrogen and androgen receptors. Further, an enzyme (aromatase)
that converts androgens to estrogens has been demonstrated in
the medial forebrain, limbic system, hippocampus, and hypothalamus.
- It was hypothesized that men had consistently
high dietary intakes of tofu during middle life would experience
different patterns of cognitive decline and dementia in late life,
compared with men reporting little or no tofu consumption.
- The Honolulu-Asia Aging Study is a longitudinal
study of aging and dementia conducted in Japanese-American men
who are members of the Honolulu Heart Program cohort. Mid-life
patterns of consumption of tofu and several other foods were defined
on the basis of food frequency interviews conducted in 1965 and
1972. The Cognitive Abilities Screening Instrument was administered
to more than three thousand surviving participants aged 71-93
years during the 1991-93 examination cycle. DSM-HI-R, NINCDS-ADRDA,
and California criteria were use for the diagnosis of dementia
(all cause), AD and VsD.
- We found an association of consistently high
levels of tofu consumption in mid-life with low cognitive test
scores (p=0.02) and (independently) with Alzheimer's disease in
late life, controlling for all other relevant variables. The odds
ratio for AD in persons who reported eating tofu at least twice
weekly was 2.4 (95% CI 1.14-5.09), compared with persons reporting
tofu consumption rarely or never.
-
- Life-style risk factors for cognitive
impairment.
- White LR, Foley DJ, Havlik RJ
- In: Strategies to prevent cognitive decline in
late life, Fillit H, Butler RN, editors. London: Greenwich
Medical Media; 1997. p. 23-32.
- Abstract
- The EDB Program of NIA is involved in an epidemiological
study of about 3,500 older Japanese-American men in Honolulu,
Hawaii. As has been mentioned, prevalence rates of Alzheimer’s
disease are higher than in Japan. This study offers some unique
features, which should be highlighted. This population has been
under observation for about 25 years; so, data were collected
many years earlier, before any effect of dementia could distort
the data. Data were primarily on cardiovascular risk factors including
dietary intake and indicators of cultural differences (more or
less traditional Japanese). Preliminary results are available
on a number of potential risk factors for Alzheimer’s disease.
There is no relationship with alcohol consumption, smoking, years
of education, or low complexity occupations including working
in sugar-cane or pineapple fields. What is unexpected, and somewhat
inconsistent with the hypothesis of westernization being related
to increased Alzheimer’s disease, is the unexplained finding
that components of the traditional Japanese diet, which include
a high intake of green tea, tofu, and miso soup, are positively
associated with Alzheimer’s disease. This finding is being
pursued in further analyses. Also, an unusual aspect of the study
is a high autopsy rate among participants. The situation will
allow study of structure-function relationships, including correlation
of ante-mortem factors with Alzheimer’s disease-specific
findings of plaques and tangles and brain size. It is quite possible
that certain factors will be related to structural changes and
others to the clinical manifestations of Alzheimer’s disease.
It should be possible to evaluate these complex interrelationships
within this rather unique population.
-
- Long-term potentiation in the hippocampus
is blocked by tyrosine kinase inhibitors.
- O'Dell TJ, Kandel ER, Grant SG
- Nature 1991 Oct 10 353:6344 558-60
- Abstract
- Long-term potentiation (LTP) in the hippocampus
is thought to contribute to memory formation. In the Ca1 region,
LTP requires the NMDA (N-methyl-D-aspartate) receptor-dependent
influx of Ca2+ and activation of serine and threonine
protein kinases. Because of the high amount of protein tyrosine
kinases in hippocampus and cerebellum, two regions implicated
in learning and memory, we examined the possible additional requirement
of tyrosine kinase activity in LTP. We first examined the specificity
in brain of five inhibitors of tyrosine kinase and found that
two of them, lavendustin A and genistein, showed substantially
greater specificity for tyrosine kinase from hippocampus than
for three serine-threonine kinases: protein kinase A, protein
kinase C, and Ca2+/calmodulin kinase II. Lavendustin
A and genistein selectively blocked the induction of LTP when
applied in the bath or injected into the postsynaptic cell. By
contrast, the inhibitors had no effect on the established LTP,
on normal synaptic transmission, or on the neurotransmitter actions
attributable to the actions of protein kinase A or protein kinase
C. These data suggest that tyrosine kinase activity could be required
postsynaptically for long-term synaptic plasticity in the hippocampus.
As Ca2+ calmodulin kinase II or protein kinase C seem
also to be required, the tyrosine kinases could participate postsynaptically
in a kinase network together with serine and threonine kinases.
-
|
