Pubdate: Sun, 28 Aug 2016
Source: Press-Enterprise (Riverside, CA)
Copyright: 2016 The Press-Enterprise Company
Author: Brooke Edwards Staggs


As Californians get ready to vote Nov. 8 on whether to legalize 
recreational marijuana, there are broader public health questions to consider.

A pregnant woman has morning sickness so severe she can't keep food 
down, so she stirs some cannabis-infused oil into her morning tea to 
regain her appetite.

An elderly man has chronic pain that keeps him up at night, so he 
smokes marijuana most nights before he and his wife go to bed.

There's a growing body of research that suggests marijuana can help 
with conditions such as nausea and pain while posing only modest 
health risks for adults. But as Californians get ready to vote Nov. 8 
on whether to legalize recreational marijuana, there are broader 
public health questions to consider, from whether it affects 
developing fetuses to the impacts of secondhand smoke.

"We often hear there are no negative effects," said Kevin Alexander, 
who works with addicts at Hoag Hospital's After School Program: 
Intervention and Resiliency Education - ASPIRE  program in Newport 
Beach. "But we need more research and information on how it would 
affect us as a community and the societal impacts."

This is the latest in an occasional series that surveys current 
research and interviews experts on common questions about marijuana 
use: the potential health risks, issues of government regulation and 
the experience of states where recreational cannabis is legal.

Q. Is cannabis dangerous for pregnant women?

A. There's no level of marijuana use that's considered "safe" for 
women who are pregnant or breastfeeding, per the experts, just as 
there's no safe level of alcohol, tobacco or many other substances.

While expectant moms report using marijuana to ease severe morning 
sickness, the American College of Obstetricians and Gynecologists 
recommends they stop using cannabis until they're finished breastfeeding.

"Although we still need more research on the topic, the data we do 
have raises concerns regarding negative effects of marijuana on the 
growing fetus," said Dr. Joseph Wax with the college.

Research published in the journal Psychopharmacology found that even 
low doses of marijuana in pregnant rats produced offspring with 
learning delays plus tremors and unusual emotional behavior.

A 2010 study by researchers out of Pittsburgh studied children at 10 
years old who'd been exposed to marijuana during pregnancy. They 
found these children were more likely to miss school and show early 
signs of depression and attention disorders.

The Pittsburgh study's authors pointed out that they couldn't say how 
environment or family might play into that equation, noting it's 
possible that a mother who smoked marijuana while pregnant simply 
passed along a predisposition for risky behavior.

More research is underway. But the American Medical Association feels 
there's enough evidence of risk to push for this warning on all 
marijuana products: "Marijuana use during pregnancy and breastfeeding 
poses potential harms."

Q. Does smoking marijuana cause lung cancer?

A. The cancer link appears increasingly weak, though more research is needed.

Marijuana contains many compounds also found in tobacco, including 
some known to cause cancer. That's triggered reports suggesting that 
smoking marijuana must be more dangerous, since it's typically 
inhaled more deeply and held in the lungs longer than tobacco.

However, research so far suggests otherwise.

A comprehensive 2014 study in the International Journal of Cancer 
found "little evidence for an increased risk of lung cancer," even 
among heavy or long-term cannabis smokers. Those results are buoyed 
by a number of other large studies, including an examination by UCLA 
in 2006 that was funded by the National Institute on Drug Abuse.

One possible explanation is that marijuana users typically don't 
smoke as often as tobacco users.

Dr. Donald Tashkin, a pulmonologist who led the UCLA study, suggested 
marijuana doesn't pose the same cancer risk as tobacco because THC 
has been found to slow the growth of some cancers.

THC is known to reduce inflammation, too, Tashkin points out, which 
may explain why there also doesn't appear to be a link between 
marijuana and chronic obstructive pulmonary disease, which plagues 
cigarette smokers.

Several studies have shown a correlation between heavy marijuana 
smoking and other respiratory conditions, such as chronic bronchitis.

There's an alternative, advocates say: Don't smoke it. While edibles 
and concentrates come with their own set of risks, lung issues aren't 
among them.

Q. Is secondhand pot smoke dangerous?

A. The jury is still out, but experts say best to avoid it.

First, there's the potential  albeit a small one  for a "contact high."

Nonsmokers who were in a car or other small, unventilated space with 
heavy marijuana smokers showed some of the same temporary, minor 
memory and coordination problems as the smokers themselves, according 
to a study by Johns Hopkins University School of Medicine. Some 
exposed nonsmokers even tested positive for the drug.

Those are considered extreme conditions. The National Institute on 
Drug Abuse notes that a contact high is highly unlikely, since very 
little THC, or the psychoactive compound in cannabis, is exhaled back 
into the air.

The more serious concern is whether secondhand pot smoke poses the 
same deadly risks as exposure to secondhand tobacco smoke. That's 
where the science isn't settled, though research largely points to 
the answer being no.

As Tashkin's studies show, even firsthand marijuana smoke doesn't 
seem to pose as big a risk of lung cancer or chronic pulmonary 
obstruction disease as cigarette smoke.

However, a 2014 study on rats by cardiovascular researcher Matthew 
Springer at UC San Francisco found secondhand marijuana smoke 
restricts blood vessels much like tobacco smoke.

That can increase chances of a heart attack, particularly for people 
who have other risk conditions.

California law says medical marijuana patients can't smoke in areas 
where tobacco is banned or within 1,000 feet of school or youth 
centers. The proposed recreational use initiative bans consumption in 
public or around children.

To be safe, experts recommend making sure there's good ventilation if 
you're around marijuana smokers. Or suggest other methods of 
ingestion, such as vaporizing, edibles or tinctures.
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MAP posted-by: Jay Bergstrom