Examine smokescreen around marijuana


Let’s pretend your teenage daughter had a pregnancy test kit in her room. She says she got it for a friend. You decide to smoke your first marijuana cigarette.

That first puff is deep, legal in this state, and strangely relaxing. You cough so hard it irritates your throat and your eyes water. You wait a minute and try again. “Mmm. Not bad.”

You may think, “Drug use may be legal but it’s wrong.” Let me suggest the scene could play out this way: Because marijuana relaxed you, you are better prepared to have a reasonable discussion and avoid a confrontation. On the other hand, you may have set a bad example and encouraged her to handle her problems in a way that is more likely to have adverse effects on young brains than old ones.

Let’s consider what we know about marijuana. You will have plenty of time to judge right from wrong after you become informed. The effect on your child and your relationship with her are at stake.

Smoke from that cigarette entered your lungs and left particulate matter on the inner lining. It accumulated at branch points where some kinds of lung cancer are common. When you coughed, your body was expressing unhappiness with your decision.

Did you put yourself at increased risk of developing lung cancer or chronic pulmonary disease that could put you in a wheelchair, while you suck oxygen through a hose?

To understand the answer to the question, begin by asking yourself how scientists study it.

Controlled studies can’t be done. We can’t take one group of people, force them to smoke, and observe them until a tumor shows up on a chest radiograph.

We are forced to ask questions after disease develops or to do studies on animals. The results have been inconsistent.

We do know that marijuana cigarettes have higher concentrations of cancer-producing polyaromatic hydrocarbons than the name brands at the checkout counter. Pot smokers tend to suck their cigarettes to the nub and hold the smoke in longer.

On the flip side, there are suggestions that THC may have anticancer properties.

One study was done in New Zealand. Technical considerations suggest it is fairly reliable. In short, that report concludes: “Long-term cannabis use increases the risk of lung cancer in young adults.”

The numbers, based on similar levels of smoking, suggest the risk is similar to or a bit higher than commercially available cigarettes.

Studies that involve lung biopsies also show damage consistent with the conclusion that marijuana increases the risk of cancer and chronic lung disease. Based on imperfect data, I would advise patients to stop smoking — anything.

OK, the next question I’m likely to hear is, “What about brownies, Doc?”

The way THC and related agents get into our blood streams may make a difference. The lung route seems to carry a greater risk than ingesting it.

I allow that the sugar in the brownies and the munchies that follow aren’t on my recommended list of healthy eating habits.

Once the cannabinoids are flooding through you, the main focus of concern involves our brain. The next paragraph is somewhat technical. Give it a shot.

Drugs affect the brain mainly by altering neural connections, the neurotransmitters. One important transmitter is GABA, short for Gamma Aminobutyric acid. GABA inhibits excitability and it is involved with muscle tone. It plays an important role in a group of nerve cells, neurons, which make connections in specific parts of the brain. Since these neurons have high levels of CB1 receptors, those parts of the brain are also particularly sensitive to cannabinoids.

Effects of cannabinoids are related to parts of the brain that have a lot of receptors. The frontal lobe effects impair judgment, while the hippocampal area, deep in the brain is necessary for memory.

Short-term memory is impaired by THC. Long-term damage is suggested, but the reports are unclear. There is data to suggest the loss improves over time, but some studies suggest permanent loss — especially with heavy use and use in younger people. Rat studies show destruction of cells in the hippocampus. There is some functional impairment that adversely impacts driving a car.

Brain damage from marijuana use is a concern, but it may pale in comparison with football injuries, boxing and booze.

From a medical standpoint, cannabinoids can be helpful to reduce stress, maintain weight in cancer and other patients, and aid in pain control and nausea. There is a long list of medical problems for which these drugs may have some benefit.

The risk of becoming addicted seems less than it is for hardcore drugs. Withdrawal symptoms are less severe when they do occur.

Readers, however, have asked me to discuss the issue of marijuana as a gateway drug. It seems consistent to many observers that hard-drug use is initiated when youngsters try marijuana. The studies are inconsistent.

A study of patterns in twins was published in 2008 and concluded the gateway effect appears to be genetically linked. In 2006, the American Journal of Psychiatry linked drug use to availability in the neighborhood and deviancy.

In short, attitudes and availability predicted use and didn’t support the concept that marijuana led to other drug usage.

A similar conclusion was reported in 2002 in the journal Addiction.

The issue isn’t settled, but there is evidence the basic problem lies in society. Since availability is a related issue, there may be justification to deal with sales to minors and sharing with minors in more effective ways than we have with alcohol.

The first reports on using cannabis date back nearly 5,000 years in China, and there is still a lot we don’t know about it. Answers will depend on our willingness to be objective and to raise a generation of science-literate citizens.

Dr. Larry Mulkerin is a retired clinical professor and oncologist who lives in Walla Walla. A former U.S. Army Green Berets medical officer with experience in the Middle East, he also is the author of “The Ayatollah’s Suitcase,” a novel available at amazon.com and other online book retailers. He can be reached at mulkerin@charter.net.


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