Marijuana has been blamed for causing chromosome damage, drug psychosis, endocrine abnormalities and heart attacks. The substance has long been considered a "gateway drug"--one that leads users to stronger substance abuse. Marijuana is a mildly addicting drug capable of causing impaired driving but with less overall health and social consequences than alcohol or tobacco. Tolerance develops and is dose-dependent over time. Side effects of marijuana use have been studied and linked to mostly cognitive effects and lung irritation. Generally, lifestyles associated with marijuana use may also have health risks.
Lower Antioxidant Levels
Researchers from the SUNY School of Medicine, University of Buffalo, New York, examined data from a health and nutrition survey and found marijuana users between the ages of 20 and 59 had lower blood levels of carotenoids, an important class of antioxidants found in brightly colored fruits and vegetables. The 2001 report explained that the subjects had poor nutrition compared to non-users, consuming more calories, salty snacks, pork, cheese, beer and soda. Antioxidant deficiencies were independent of tobacco use. Antioxidants are needed for cellular protection and repair, and play a key role in slowing aging and immune response.
Lower IQ
Canadian scientists from Carlton University in Ontario published a study in 2002 that followed 70 subjects since birth. IQ scores were assessed at ages 9 to 12 and compared with current scores of 17- to 20-year-old marijuana users, identified by urine drug screens and interviews. Heavy smokers, defined as those using marijuana at least five times a week, had an average decrease of 4.1 points in IQ score. IQ scores increased an average of 3.5 points for formerly heavy users who had been abstinent for at least three months, showing the loss was temporary. However, current light users (less than five times per week), had the largest gains, adding an average of 5.8 points.
Respiratory Tract Damage
"Regular marijuana use can lead to extensive airway injury and alterations in the structure and function of alveolar macrophages, potentially predisposing to pulmonary infection and respiratory cancer." These are the findings of D.P. Tashkin, of the UCLA School of Medicine and published in the March, 2001 issue of "Current Opinion in Pulmonary Medicine." Avleolar macrophages are tiny hairs that sweep mucus and debris out of the lungs. Marijuana smoke contains substances known to cause cancer, according to the American Cancer Society, and chronic use can lead to laryngitis and bronchitis.
Psychiatric
According to L. E. Hollister of the Harris County Psychiatric Center, University of Texas at Houston, marijuana does not create psychosis in users with no history or predisposition to mental illness. However, there is evidence, derived from retrospective studies, of exacerbation of schizophrenia in those predisposed to this psychotic disorder. In his 1998 article published in the "International Journal of Neuropsychopharmacology," Hollister cautioned that results of retrospective studies be open to question.
References
- National Institutes of Health: Marijuana and Nutritional Health
- National Institutes of Health: International Journal of Neuropsychopharmacology: Dietary Intake and Nutritional Status of U.S. Adult Marijuana Users
- Canadian Medical Association Journal: Marijuana Use and IQ
- Current Opinion in Pulmonary Medicine: Marijuana Use and Pulmonary Effects
- American Cancer Society: Marijuana
