BAD DOPE

MARIJUANA damages DNA as much as tobacco, creating potentially fertile
ground for cancers, according to a study of mothers and their newborn infants.

Marijuana smoke contains many of the same carcinogenic chemicals found in
cigarette smoke, and people tend to hold marijuana smoke longer in their
lungs. Epidemiologists have not yet linked marijuana to cancer, but this
may be because cancers take decades to develop and widespread marijuana use
is a recent phenomenon.

Marinel Ammenheuser and her colleagues at the University of Texas Medical
Branch in Galveston set out to discover whether marijuana smoke directly
damages DNA. Using blood and urine tests, the researchers identified 17
pregnant women who smoked marijuana but did not use tobacco, cocaine or
heroin. The study also enrolled an equal number of women who used none of
the drugs.

The researchers collected blood from each woman and from 10 umbilical
cords. They found that the frequency of mutations in the DNA was nearly
three times as high in the marijuana smokers and their infants as in
nonsmokers (Mutation Research, vol 403, p 55).

Ammenheuser says that the increased mutation rate in marijuana users
resembles that found in tobacco smokers. "It's only a hint that there may
be trouble there, but it's scientifically plausible."

"There's more and more evidence from our lab showing increased levels of
mutations in lungs," says Michael Roth of the University of California's
Los Angeles Medical Center. His group will publish a study next month in
the Journal of the National Cancer Institute showing that marijuana is
associated with mutations known to be linked to lung cancer. He also has
preliminary evidence suggesting that THC, the mood-altering ingredient in
marijuana, may promote the carcinogenic effect.

Checked-by: Mike Gogulski