Chromium 6 and vitamin
C, a deadly combination
PROVIDENCE
,
R.I.
- Vitamin C can
kill. That is, when mixed with chromium 6.
Naturally occurring vitamin C reacts inside human lung cells with
chromium 6, or hexavalent chromium, causing massive DNA damage, according to
Brown
University
researchers.
When combined with vitamin C, even low doses of chromium 6 can produce
up to 15 times as many chromosomal breaks and up to 10 times more mutations
than cells that lack vitamin C altogether.
Such phenomena are forms of genetic damage that lead to cancer.
However, vitamin C is not always harmful.
In fact, when outside cells, vitamin C protects
against the cellular damage caused by hexavalent chromium, according to Anatoly
Zhitkovich, an associate professor of medical science at Brown who oversaw the
experiments.
Vitamin C has been used as an antidote in industrial accidents
when large amounts of chromium were ingested. This was the case in the
Hollywood blockbuster,
Erin Brockovich
that featured the compound hexavalent
chromium as its villain
.
Vitamin C is a powerful antioxidant that blocks cellular damage
from free radicals.
As it rapidly adds
electrons, to free radicals, the vitamin converts them into harmless molecules.
This electron transfer produces chromium 3, a form of the compound unable to
enter cells.
However, expect the unexpected when chromium and vitamin C come
together, inside cells.
Zhitkovich and his team
conducted experiments using human lung cells supplemented with vitamin C.
When vitamin C was present, chromium
reduction had a very different effect. Cellular vitamin C sparked considerably
more chromosomal breaks and cellular mutations, acting as a potent toxic
amplifier.
Increasing the concentration of vitamin C inside cells provoked more
mutations and DNA breaks, turning chromium toxic, said Zhitkovich.
It had been unknown until now, with the
presence of vitamin C, how exposure to small amounts of hexavalent chromium can
cause high rates of cancer.
Hexavalent chromium is a compound used to make paints, dyes,
plastics and inks, and to plate metals.
Hexavalent
chromium is found in 40 percent of Superfund sites nationwide and causes lung
cancer.
The research, published in
Nucleic Acids Research, may
have policy implications, according to Zhitkovich,. Chromium 6 caused genetic
damage in cells in doses four times lower than current federal standards when
combined with vitamin C, Zhitkovich said.
He also said federal regulators might want to lower exposure standards
if additional research backs these findings.
