CANNABIS

The Good and Bad: Glaucoma Reliever, Social Lubricant, Cancer And
Depression Promoter. and a Lot More

As a teenager, Dom Cramer's anti-drug attitudes would have made any
parent proud. He bought into the "Just Say No" government campaigns
and the warnings from the police who visited his high school that
marijuana was a surefire gateway to more hard-core drugs.

Today, Cramer owns the Toronto Hemp Company, a Yonge Street store that
sells everything from hemp soaps and lip balms to rolling machines and
"defunk smell remover spray." Cramer, now 30, began smoking pot in
university, after he stopped believing "all the lies I was taught in
high school." He smokes marijuana frequently, although says he can go
for weeks or months without it.

Cramer calls cannabis the ideal "social lubricant -- something to do
instead of drinking alcohol, something to share with people and bond
people." The drug also "helps take your mind off things, it helps you
relax."

Even experts believe cannabis can have positive health and
physiological effects, and groups such as Canadians for Safe Access
argue that the health repercussions of recreational marijuana use
would never come close to matching the harm done by cigarettes or alcohol.

The debate over the health impact of marijuana took on renewed
significance when the Liberal government introduced Bill C-10 in the
House of Commons last month. The bill would decriminalize the
possession of small amounts of marijuana. Possession of up to 15 grams
of pot and up to three marijuana plants would be punishable under the
new law by tickets and fines of between $100 and $500.

According to the 2002 special Senate committee report on illegal drug
use, close to 30 per cent of the Canadian population aged 12 to 64 has
used cannabis at least once. About two million Canadians aged 18 and
older have used cannabis during the past 12 months, 600,000 have used
the drug in the past 30 days, and approximately 10,000 use it daily.
(The committee sharply criticized health officials for failing to
monitor pot use, saying knowledge of patterns of cannabis use in
Canada "verges on the abysmal." They relied on epidemiological data
from two surveys, in 1989 and 1994, to estimate marijuana use.)

Canada has one of the highest rates of cannabis use among youths, the
committee reported: About one million teens aged 12 to 17 used pot
sometime in the past year, 750,000 in the past month and 225,000
appear to smoke it daily. Among youth, the "average age of
introduction" to pot is 15.

But experts say that many recreational users don't smoke enough
marijuana to produce the high concentrations that are needed to do
serious harm.

"It's like cigarettes," says Dr. Thomas Klein, professor of medical
microbiology and immunology at the University of South Florida.

"I think most rational people would say, 'Well, you smoke a cigarette
from time to time, or a cigar from time to time, it's not going to
hurt you. But if you smoke three packs a day it is. It's the same
situation with marijuana."

Still, like most drugs, there's a relatively narrow margin of safety
between the effects you want, and the ones you don't.

"Let's begin with the beneficial effects, because there's much less to
say about that, " says Dr. Harold Kalant, professor emeritus in the
University of Toronto's department of pharmacology.

Marijuana induces relaxation "and a sense of easier communication with
other people," Kalant says. "And things are funnier." Once the initial
acute phase is over, people feel drowsy, "and it may help some people
get to sleep." Doctors commonly prescribed marijuana as a sedative in
the 19th century.

THC (tetrahydrocannabinol), the active ingredient in pot, has been
shown to blunt the nausea and vomiting caused by cancer treatments and
anti-HIV drug cocktails. THC can also lower the pressure within the
eyeball, making it a potential treatment of glaucoma.

Glaucoma afflicts more than 200,000 Canadians and is the second
leading cause of blindness. A number of private and university
laboratories are working on a water-soluble derivative of THC that
could be used as eye drops, with minimal effects on the body.

Meanwhile, researchers at the McGill Pain Centre in Montreal are
testing the effects of different strains of smoked cannabis on
neuropathic pain -- the electric, burning, stabbing pain caused by
severed or damaged nerves. Anecdotal reports suggests it may also help
ease muscle spasms in diseases such as multiple sclerosis. At high
enough concentrations, THC works like an anti-inflammatory. Scientists
are investigating whether the drug may help with autoimmune disorders
such as rheumatoid arthritis, where the immune system attacks the
body's own tissues.

Finally, a synthetic form of marijuana has been shown to reduce
agitation in Alzheimer's patients.

That's the good news. Here's the bad.

THC, the main ingredient in marijuana, is extremely fat soluble, which
means it can easily seep through the fatty part of the lining of the
cells in our body. Once inhaled, pot is absorbed through the lungs,
where it's diffused into the blood via tiny capillaries, then
immediately ferried to the brain and the rest of the body.

Researchers have found "receptors" -- the communication link between
the outside of the cell, and the machinery within -- for THC in the
brain, stomach, pancreas, spleen, lymph nodes and disease-fighting
white blood cells in bone marrow.

When THC binds to cells, it changes their function. In some cases,
that can be good. In the spleen, for example, THC is believed to help
suppress inflammation. But there are also an increased risk of cancers
among children born to women who smoked marijuana during their
pregnancy, and THC may further impair a person's immune defences in
those who are already immune suppressed, including living with HIV or
AIDS.

Marijuana has been found to be a potent trigger for heart attacks,
just as surveys suggest marijuana use in middle-aged adults, the group
most prone to coronary artery disease, is growing.

THC causes blood vessels to relax, which in turn can lower blood
pressure, decreasing blood flow to the heart causing the heart rate to
go up by about 10 to 20 beats per minute -- not enough to cause
trouble for most people, unless you already suffer from restricted
blood flow to the heart.

In a study of heart attack survivors, researchers at Beth Israel
Deaconess Medical Center in Boston have found that the risk of another
heart attack increased nearly five-fold in the first hour after
smoking marijuana. What's more, smoked marijuana rushes through the
blood almost as fast as if it were injected intravenously, Kalant says.

Marijuana may also cause a heart attack by causing plaque inside an
artery to rupture and form a clot, which in turn can block blood flow
to the heart muscle.

Other studies have found regular pot use can lead to male infertility
by causing sperm to swim abnormally fast. The drug may also fuel the
growth of cancerous tumors, and it has been linked to anxiety and
panic attacks even in first-time users. Research is also incriminating
pot in an increased risk of depression.

Then there are the neurotoxic effects of heavy use (more than five
joints a week) on learning, memory, intelligence, attention and other
brain functions.

Researchers at Carleton University in Ottawa once tracked 70 people
and compared their IQ scores at two stages: when they were aged nine
to 12, before they started using marijuana, and again at ages 17 to
20. They found that the IQ scores of heavy users dropped by about four
points on average.

However, the effects on the brain of long-term, recreational use
(fewer than five joints a week) appear to be minimal. Last summer,
researchers who reviewed 15 previously published studies on the
residual effects of cannabis reported that they found little evidence
of "deleterious" effects on brain functioning. "The only exception was
a very small effect in learning new information," says Dr. Igor Grant,
director of the Center for Medicinal Cannabis Research at the
University of California, San Diego.

The Carleton University intelligence study, in fact, found that IQ
scores increased in light users by a mean score of nearly six points
- --more than former users, and nearly double that of non-users.

Smoking anything isn't good for you. According to the U.S. National
Institute on Drug Abuse, the amount of tar inhaled in marijuana smoke
and the level of carbon monoxide absorbed is three to five times
higher than among tobacco smokers, probably because people who smoke
pot tend to inhale more deeply and hold the smoke in longer.

But, pot may hold its own when compared to alcohol. According to an
article published in Cannabis Culture Magazine, pot can be a
substitute for alcohol, which means that, even if the new drug law
leads to an increase in use (which studies in countries such as the
Netherlands suggest it won't) it may result in a decrease in
alcohol-related "illnesses, fatalities, violence and accidents."

Marijuana can impair driving skills by slowing reaction times, a
person's ability to steer or to make quick decisions in an emergency.
But unlike alcohol, pot tends to make drivers less aggressive, not
more. That means they're less likely to speed or pass recklessly.

Still, pot has been implicated in 10 to 15 per cent of accidents and
impaired-driving charges involving people who weren't drinking.

And survey studies show teenagers are more likely to be driving under
the influence of cannabis than alcohol, because they know there's no
quick, roadside breath test for pot, Kalant says.

"That's really quite worrying because kids are more likely to get
involved in accidents anyway, because they think they're immortal,
particularly boys in their late teens," says Kalant, who is also a
former director of biological and behavioral research for the
Addiction Research Foundation (now the Centre for Addiction and Mental
Health.)

But teens who smoke marijuana may be less likely to practise unsafe
sex than teens who drink. British scientists recently reported that as
few as two pints of beer increase how attractive members of the
opposite sex appear by about 25 per cent. The team believes the
so-called "beer goggles phenomenon" results when booze stimulates the
part of the brain that's used to score facial attractiveness.

Both pot and alcohol reduce inhibitions and self-control. "But I would
think probably it's true that it's more so with alcohol than pot,"
Kalant says.

"You see aggressive, violent behaviour after heavy drinking, much more
than you are likely to see smoking a lot of pot. If anything, the pot
user is more likely to become rather placid."

Despite his concerns, Kalant supports the government's move to convert
possession of small amounts of marijuana to a civil violation. There's
no convincing evidence, he argues, that decriminalization will lead to
a significant increase in use.

"Society continues to show disapproval of the use by imposing a fine.
It's not as if society is suddenly saying to teenage kids, 'It's okay,
we don't think it's a problem any more, you can go ahead and use.'
"

For parents, it may be enough simply knowing their children won't go
to jail, won't have criminal records and won't be denied jobs in the
future, he said.

"Parents would just as soon as their kids didn't smoke pot, but at
least now their worries about the effects of the law being worse than
the effects of the drug are removed."