HEAVY MARIJUANA USE LINKED TO RISK OF HEART ATTACKS

But Skeptics Say Study Subjects Were Smoking 78 to 350 Joints Per Week

WASHINGTON - Heavy marijuana use can boost blood levels of a
particular protein, perhaps raising a person's risk of a heart attack
or stroke, U.S. government researchers said Tuesday.

Dr. Jean Lud Cadet of the National Institute on Drug Abuse, part of
the National Institutes of Health, said the findings point to another
example of long-term harm from marijuana. But marijuana activists
expressed doubt about the findings.

Cadet said a lot of previous research has focused on the effects of
marijuana on the brain. His team looked elsewhere in the body,
measuring blood protein levels in 18 long-term, heavy marijuana users
and 24 non-users.

Levels of a protein called apolipoprotein C-III were found to be 30
per cent higher in the marijuana users compared to the others. This
protein is involved in the body's metabolism of triglycerides -- a
type of fat found in the blood -- and higher levels cause increased
levels of triglycerides, Cadet added.

High levels of triglycerides can contribute to hardening of the
arteries or thickening of the artery walls, raising the risk of
stroke, heart attack and heart disease.

The study did not look at whether the heavy marijuana users actually
had heart disease.

"Chronic marijuana abuse is not so benign," Cadet, whose study is in
the journal Molecular Psychiatry, said in a telephone interview.

The marijuana users in the study averaged smoking 78 to 350 marijuana
cigarettes per week, based on self-reported drug history, the researchers said.

The researchers said the active ingredient in marijuana, known as
THC, seems to overstimulate marijuana receptors in the liver, leading
to overproduction of the protein.

People with major medical or psychiatric illness, alcohol dependency
and other drug use such as cocaine or heroin were excluded from the study.

A U.S. group supporting legal sales and regulation of marijuana
disputed the findings. Marijuana Policy Project spokesman Bruce
Mirken said, for example, the study involved people who were
extremely heavy users.

"I think the low end was 78 joints a week. That's 10 or 11 joints a
day," Mirken said in a telephone interview.

"We're talking about people who are stoned all the time. We're
talking about the marijuana equivalent of the guy in the alley
clutching a bottle of cheap wine. If you do anything to that level of
excess, it might well have some untoward effects, whether it's
marijuana or wine or broccoli," Mirken added.

Cadet's team said the findings suggest long-term harm from marijuana
beyond issues such as impaired learning, poor memory retention and
retrieval and perceptual abnormalities.

But Mirken said: "Even if you take this finding at face value, it's
not at all clear that it has any relevance to the real world because
there is still no data showing higher rates of mortality among
marijuana smokers. If this was a significant cause of cardiovascular
disease, where are the bodies?"