popNfresh44
Active member
it has been questionable to me until now. this test was done at the university of california, and was the biggest controlled test done.
Study Finds No Cancer-Marijuana Connection
By Marc Kaufman
Washington Post Staff Writer
Friday, May 26, 2006; A03
The
largest study of its kind has unexpectedly concluded that smoking
marijuana, even regularly and heavily, does not lead to lung cancer.
The
new findings "were against our expectations," said Donald Tashkin of
the University of California at Los Angeles, a pulmonologist who has
studied marijuana for 30 years.
"We hypothesized that there would
be a positive association between marijuana use and lung cancer, and
that the association would be more positive with heavier use," he said.
"What we found instead was no association at all, and even a suggestion
of some protective effect."
Federal health and drug enforcement
officials have widely used Tashkin's previous work on marijuana to make
the case that the drug is dangerous. Tashkin said that while he still
believes marijuana is potentially harmful, its cancer-causing effects
appear to be of less concern than previously thought.
Earlier
work established that marijuana does contain cancer-causing chemicals
as potentially harmful as those in tobacco, he said. However, marijuana
also contains the chemical THC, which he said may kill aging cells and
keep them from becoming cancerous.
Tashkin's study, funded by the
National Institutes of Health's National Institute on Drug Abuse,
involved 1,200 people in Los Angeles who had lung, neck or head cancer
and an additional 1,040 people without cancer matched by age, sex and
neighborhood.
They were all asked about their lifetime use of
marijuana, tobacco and alcohol. The heaviest marijuana smokers had
lighted up more than 22,000 times, while moderately heavy usage was
defined as smoking 11,000 to 22,000 marijuana cigarettes. Tashkin found
that even the very heavy marijuana smokers showed no increased
incidence of the three cancers studied.
"This is the largest
case-control study ever done, and everyone had to fill out a very
extensive questionnaire about marijuana use," he said. "Bias can creep
into any research, but we controlled for as many confounding factors as
we could, and so I believe these results have real meaning."
Tashkin's
group at the David Geffen School of Medicine at UCLA had hypothesized
that marijuana would raise the risk of cancer on the basis of earlier
small human studies, lab studies of animals, and the fact that
marijuana users inhale more deeply and generally hold smoke in their
lungs longer than tobacco smokers -- exposing them to the dangerous
chemicals for a longer time. In addition, Tashkin said, previous
studies found that marijuana tar has 50 percent higher concentrations
of chemicals linked to cancer than tobacco cigarette tar.
While
no association between marijuana smoking and cancer was found, the
study findings, presented to the American Thoracic Society
International Conference this week, did find a 20-fold increase in lung
cancer among people who smoked two or more packs of cigarettes a day.
The
study was limited to people younger than 60 because those older than
that were generally not exposed to marijuana in their youth, when it is
most often tried.
Study Finds No Cancer-Marijuana Connection
By Marc Kaufman
Washington Post Staff Writer
Friday, May 26, 2006; A03
The
largest study of its kind has unexpectedly concluded that smoking
marijuana, even regularly and heavily, does not lead to lung cancer.
The
new findings "were against our expectations," said Donald Tashkin of
the University of California at Los Angeles, a pulmonologist who has
studied marijuana for 30 years.
"We hypothesized that there would
be a positive association between marijuana use and lung cancer, and
that the association would be more positive with heavier use," he said.
"What we found instead was no association at all, and even a suggestion
of some protective effect."
Federal health and drug enforcement
officials have widely used Tashkin's previous work on marijuana to make
the case that the drug is dangerous. Tashkin said that while he still
believes marijuana is potentially harmful, its cancer-causing effects
appear to be of less concern than previously thought.
Earlier
work established that marijuana does contain cancer-causing chemicals
as potentially harmful as those in tobacco, he said. However, marijuana
also contains the chemical THC, which he said may kill aging cells and
keep them from becoming cancerous.
Tashkin's study, funded by the
National Institutes of Health's National Institute on Drug Abuse,
involved 1,200 people in Los Angeles who had lung, neck or head cancer
and an additional 1,040 people without cancer matched by age, sex and
neighborhood.
They were all asked about their lifetime use of
marijuana, tobacco and alcohol. The heaviest marijuana smokers had
lighted up more than 22,000 times, while moderately heavy usage was
defined as smoking 11,000 to 22,000 marijuana cigarettes. Tashkin found
that even the very heavy marijuana smokers showed no increased
incidence of the three cancers studied.
"This is the largest
case-control study ever done, and everyone had to fill out a very
extensive questionnaire about marijuana use," he said. "Bias can creep
into any research, but we controlled for as many confounding factors as
we could, and so I believe these results have real meaning."
Tashkin's
group at the David Geffen School of Medicine at UCLA had hypothesized
that marijuana would raise the risk of cancer on the basis of earlier
small human studies, lab studies of animals, and the fact that
marijuana users inhale more deeply and generally hold smoke in their
lungs longer than tobacco smokers -- exposing them to the dangerous
chemicals for a longer time. In addition, Tashkin said, previous
studies found that marijuana tar has 50 percent higher concentrations
of chemicals linked to cancer than tobacco cigarette tar.
While
no association between marijuana smoking and cancer was found, the
study findings, presented to the American Thoracic Society
International Conference this week, did find a 20-fold increase in lung
cancer among people who smoked two or more packs of cigarettes a day.
The
study was limited to people younger than 60 because those older than
that were generally not exposed to marijuana in their youth, when it is
most often tried.
have fun getting high
