Pubdate: Tue, 12 Jun 2001
Source: Globe and Mail (Canada)
Copyright: 2001, The Globe and Mail Company
Contact:  http://www.globeandmail.ca/
Details: http://www.mapinc.org/media/168
Author: Daniel Leblanc, with a report from Reuters

BOOMERS FACE EXTRA RISK FROM MARIJUANA

Ottawa -- Middle-aged pot users face a fivefold increase in the risk of
a heart attack in the hour after they smoke the drug, which makes it
slightly riskier for baby boomers than strenuous exercise such as sex, a
new study says.

"The risk with marijuana use was a little higher than what was observed
for sexual intercourse," said Dr. Murray Mittleman, director of
cardiovascular epidemiology at Beth Israel Deaconess Medical Center in
Boston.

Dr. Mittleman said his study comes at a critical time, because
"marijuana use in the age group prone to coronary artery disease is
higher than it was in the past."

The risk of a heart attack starts increasing in men at about age 45, and
a few years later in women.

"As with any risk factor for heart attack, or for heart disease in
general, the risks become more pertinent as we grow older. Marijuana use
is no exception," Dr. Mittleman said.

A Canadian expert on the medical hazards of marijuana said the study
sent a simple message to middle-aged drug users: "It's probably a good
time to quit," said Dr. Harold Kalant, professor emeritus at the
University of Toronto.

Dr. Kalant said that young people's hearts are simply stronger and can
better withstand the impacts of drug-induced euphoria. "The cardiac
workload is increased. For young people, that doesn't mean anything,
they can easily adapt. But for older people, the increased workload on
the heart will be a risk factor for a heart attack."

Dr. Kalant added that most marijuana smokers quit before they reach
their 40s anyway. "As they get on with their careers, I think, they
don't like the memory problems, the fuzzy-headedness and so on."

Smoking marijuana causes the heart rate to increase -- often doubling it
- -- while altering blood pressure, according to the study. It may also
trigger a heart attack by causing the formation of a clot, blocking the
flow of blood to the heart muscle. The researchers said that smoking
marijuana can also increase the heart's demand for oxygen, while at the
same time decreasing the supply of oxygen, causing the organ to break
down.

Dr. Mittleman added that cocaine use is much riskier, causing about a
25-fold increased risk of a heart attack during the first hour.

During their investigation, researchers found a few people who engaged
in both sexual intercourse and marijuana use just before their heart
attack, but not enough to scientifically determine whether the
combination of the two further increased the health risk.

The study appeared in the journal Circulation, published by the American
Heart Association. It is based on interviews with almost 4,000 people
who had heart attacks, including 124 marijuana smokers.

During the study, researchers found nine patients who reported smoking
marijuana within one hour of the onset of heart attack symptoms.
Researchers calculated the estimated risk by comparing the frequency of
marijuana use before heart attack symptoms began, to the frequency of
marijuana use over the previous year.

The study came just as the Senate continued its hearings into illegal
drugs in Ottawa, and most notably on whether marijuana laws should be
loosened.

Dr. Kalant warned the committee members that a liberalization of
marijuana possession laws, especially if the drug became cheaper, would
lead "to an increase in use and in adverse affects."

Dr. John Morgan, a professor of pharmacology at the City University of
New York Medical School, countered that international experience shows
that looser drug laws do not lead to an increase in drug use. Dr. Morgan
also tried to debunk the theory that marijuana is a "gateway drug,"
leading users to try harder drugs, as Canadian police told the committee
recently.

In an interview, he admitted that drug tourists would likely come to
Canada if the country were to liberalize its laws.

"It's one of the things that Canada will have to consider, but it's okay
because the drug laws in the United States are so unjust," he said.
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