IT'S TIME TO QUIT, DOCTOR TELLS MIDDLE-AGED POT USERS

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," he said.

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 oxygen.

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 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 experience shows that
looser drug laws do not lead to an increase in drug use.