From: Ian Goddard (Ian@Goddard.net)
Date: Mon Aug 28 2000 - 10:04:19 MDT
Below this report from Dr Gabe Mirkin is the abstract
of the study Mirkin cites on the possibility of a link
between Alzheimer's disease and zinc, which is followed
by the abstract of a recent study (2000) on this topic:
http://www.drmirkin.com/archive/6325.html
ZINC CAUSES ALZHEIMER'S DISEASE?
Report #6325 9/6/94
More than 20 years ago, scientists reported a link between
aluminum and Alzheimer's disease, a condition that causes
senility. Now, most serious scientists do not consider
aluminum a factor, but a recent report in the journal,
Science, shows that another mineral, zinc, may be associated
with that disease.
Scientists have known for years that an abnormal protein
called beta amyloid accumulates in the brains of people with
Alzheimer's disease. Previously, scientists thought that it
takes years for beta amyloid to form, but Dr. Rudolph Tanzi
of the Massachusetts General Hospital was able to form beta
amyloid a couple of minutes after adding high doses of zinc
to brain tissue. Brain tissue normally contains very small
amounts of zinc.
You certainly should not try to avoid foods that are rich
sources of zinc, such as meat, liver, eggs, and seafood.
Lack of zinc can cause loss of taste and smell, decreased
ability to fight infections and loss of memory. However, it
may be prudent to avoid zinc pills. In 1991, a study from
the University of Melbourne in Australia was discontinued
after only two days because giving zinc supplements to
subjects with Alzheimer's disease caused a rapid
deterioration of their mental abilities. In 1980, another
study showed that taking large doses of zinc lower blood
levels of the good HDL cholesterol that prevents heart attacks.
I'm Dr. Gabe Mirkin on Fitness.
http://www.drmirkin.com/archive/6325.html
==============================================================
Science 1994 Sep 2;265(5177):1464-7
Rapid induction of Alzheimer A beta amyloid formation by zinc.
Bush AI, Pettingell WH, Multhaup G, d Paradis M, Vonsattel JP,
Gusella JF, Beyreuther K, Masters CL, Tanzi RE
Laboratory of Genetics and Aging, Massachusetts General
Hospital, Boston.
A beta 1-40, a major component of Alzheimer's disease cerebral
amyloid, is present in the cerebrospinal fluid and remains
relatively soluble at high concentrations (less than or equal
to 3.7 mM). Thus, physiological factors which induce A beta
amyloid formation could provide clues to the pathogenesis of
the disease. It has been shown that human A beta specifically
and saturably binds zinc. Here, concentrations of zinc above
300 nM rapidly destabilized human A beta 1-40 solutions,
inducing tinctorial amyloid formation. However, rat A beta
1-40 binds zinc less avidly and is immune to these effects,
perhaps explaining the scarcity with which these animals form
cerebral A beta amyloid. These data suggest a role for cerebral
zinc metabolism in the neuropathogenesis of Alzheimer's disease.
===============================================================
J Nutr 2000 May;130(5S Suppl):1488S-92S
Alzheimer's disease, beta-amyloid protein and zinc.
Huang X, Cuajungco MP, Atwood CS, Moir RD, Tanzi RE, Bush AI
Laboratory for Oxidation Biology, Genetics and Aging Unit,
Department of Psychiatry, Harvard Medical School,
Massachusetts General Hospital, Charleston, MA 02129, USA.
Alzheimer's disease (AD) is characterized by amyloid deposits
within the neocortical parenchyma and the cerebrovasculature.
The main component of these predominantly extracellular
collections, Abeta, which is normally a soluble component of
all biological fluids, is cleaved out of a ubiquitously
expressed parent protein, the amyloid protein precursor (APP),
one of the type 1 integral membrane glycoproteins. Considerable
evidence has indicated that there is zinc dyshomeostasis and
abnormal cellular zinc mobilization in AD. We have characterized
both APP and Abeta as copper/zinc metalloproteins. Zinc, copper
and iron have recently been reported to be concentrated to 0.5
to 1 mmol/L in amyloid plaque. In vitro, rapid Abeta aggregation
is mediated by Zn(II), promoted by the alpha-helical structure
of Abeta, and is reversible with chelation. In addition, Abeta
produces hydrogen peroxide in a Cu(II)/Fe(III)-dependent manner,
and the hydrogen peroxide formation is quenched by Zn(II).
Moreover, zinc preserves the nontoxic properties of Abeta.
Although the zinc-binding proteins apolipoprotein E epsilon4
allele and alpha(2)-macroglobulin have been characterized as
two genetic risk factors for AD, zinc exposure as a risk factor
for AD has not been rigorously studied. Based on our findings,
we envisage that zinc may serve twin roles by both initiating
amyloid deposition and then being involved in mechanisms
attempting to quench oxidative stress and neurotoxicity derived
from the amyloid mass. Hence, it remains debatable whether zinc
supplementation is beneficial or deleterious for AD until
additional studies clarify the issue.
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GODDARD'S JOURNAL: http://www.erols.com/igoddard/journal.htm
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Asking the "wrong questions," challenging the Official Story
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