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
Bookmark: http://www.mapinc.org/mjcn.htm (Cannabis - Canada)

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.
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MAP posted-by: Josh Sutcliffe