- SAN DIEGO (Reuters
Health) - 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, 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," he said.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
- 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 added.