June 24, 2008
Marijuana is Dangerous, but Maybe Not the Way You Think
By Dr. Paul Saville
Inhaling the smoke of burning coal, wood or leaves is bad for you. Acrid smoke injures the lungs and leads to chronic obstructive lung disease. Smoke contains chemicals such as benzpyrene, which causes cancer. Slow-burning cigarettes release carbon monoxide as well as carbon dioxide.
The body senses a lack of oxygen in the blood and increases the red blood count. The blood is now thicker and flows more slowly through narrowed arteries increasing symptoms of angina and a leg artery disease called claudication.
People do not smoke cigarettes for the smoke, but to obtain the effects of the nicotine that is present in tobacco leaves. Nicotine does not cause COPD or lung cancer, but is a stimulant that decreases appetite. It also acts on artery walls leading to disease of coronary (heart attack and angina), carotid (stroke) and leg arteries.
Marijuana smoke has the same effect as tobacco - lung disease and cancer. The object of smoking it is to obtain the effect of the drug cannabis in marijuana, nicotine from tobacco, which is driven off by the heat of burning leaves.
There is now strong evidence that cannabis turns on a gene that codes for schizophrenia.
Schizophrenia is the most devastating psychiatric disease which comes on between puberty and age 40, usually under 30. Those who saw or read "A Beautiful Mind" may remember John Nash Jr. of Bluefield, who won the Nobel Prize in economics for his research in mathematical game theory. He did the work at 21 and became schizophrenic at 22. Now 80 years old, he has been unable to work since he was 22. His son became a professor of mathematics at Marshall University, but is now also schizophrenic.
If in a university of 30,000 individuals under 40, at least 2 percent might be genetically predisposed to develop schizophrenia. This would give 600 possible cases. Exposure to cannabis grew fourfold in the past 30 years. Also, selective breeding has provided more potent marijuana plants. Model projections suggest up to one- fourth of new cases of schizophrenia could be due to cannabis by 2010.
A Swedish study on this issue is unique because at birth Swedes are assigned a number that includes birth month, year, county and sex. This becomes the army number, hospital number, bank number and social security number. Sweden has a military draft. All men are examined at 18 years. So it was possible to examine and follow 45,570 men for 15 years and find a causal relationship between the incidence and severity of schizophrenia and marijuana smoking. Heavy cannabis users were six times more likely to develop schizophrenia.
Cannabis increases body weight. When we eat food, we gradually feel full and stop eating, not because the stomach is distended, but because food absorbed through the intestinal wall releases chemicals which reach the brain and attach to receptors so that the brain tells us to stop eating. Cannabis attaches to these brain receptors blocking them from the intestinal chemicals. Since we do not feel full, we continue eating and get fat. This can be useful for someone with a wasting disease such as AIDS or tuberculosis, but not for most of us.
Marijuana is clearly dangerous. Should it be legalized? In the Framingham study reported in the New England Journal of Medicine, legal cigarette smoking decreased from 52 percent in the late 1970s to 15 percent in 2000. Illegal marijuana smoking has increased by 400 percent in the same period.
Making marijuana legal may be considered cool to young males. But perhaps we should use similar methods to decrease use of marijuana as have been successful with tobacco. First, maintain a drumbeat of hostile information about it. Next, have the same restrictions on its use as for tobacco, and finally, tax it. The tax should start low and slowly increase in order to wipe out the drug dealers. Tax money should be used to fund decent asylums for the insane who cannot care for themselves.
Saville, of Charleston, is a retired rheumatologist.