Water Tied to Alzheimer's
Adding support to a controversial theory linking aluminum with
Alzheimer's disease, new research indicates the disease is more
common in regions of northwest Italy where levels of aluminum
in drinking water are highest.
And when the investigators studied
the effects of one form of the metal on two types of human cells
in the lab, they found it hastened cell death.
"We were absolutely surprised by
these results," said study author Dr. Paolo Prolo, a researcher
at the University of California at Los Angeles. "I did not expect
any effect from aluminum."
In findings released here Monday
at the annual Experimental Biology meeting, Prolo and colleagues
focused on monomeric -- single molecule -- aluminum. This is the
type that can be most easily absorbed by human cells, he said.
While there have been suggestions
that aluminum cookware might pose a risk for Alzheimer's, the
type of aluminum used in pots and pans consists of multiple molecules
and does not appear to affect human cells, according to Prolo.
"There is almost no evidence that the cookware is dangerous,"
When the researchers tested water
in regions of northwest Italy in 1998, they found that total aluminum
levels -- including monomeric and other types of aluminum -- ranged
from 5 to 1,220 micrograms per liter, while monomeric aluminum
levels alone ranged from 5 to 300 micrograms per liter.
Environmental officials generally
recommended that total aluminum levels be below 200 micrograms
per liter, Prolo noted.
After comparing this data to death
rates from Alzheimer's in those regions, the researchers found
that the disease was more common in areas with the highest levels
of monomeric aluminum.
Back in the lab, Prolo and colleagues
then tested the effects of monomeric aluminum on human immune-system
cells and bone cancer cells. Ideally, human brain cells would
be tested but these are not readily available because a biopsy
of a patient's brain is necessary to acquire them, he said.
"We found that a very low quantity
of aluminum added to our cell cultures was modifying cellular
processes" like normal cell death, Prolo told Reuters Health.
When the aluminum was paired with
beta-amyloid, a protein found in the brains of Alzheimer's patients,
the combination killed off even more cells.
Because aluminum could kill both
types of human cells, these findings raise the question of whether
aluminum is potentially involved in other diseases, Prolo said.
But much more research is needed
to understand how the metal does or does not affect people, he
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