“Marijuana Smoke Not as Damaging as Tobacco, Says Study (ABC News)”
http://news.yahoo.com/photos/marijuana-poses-no-threat-to-lungs-1326344236-slideshow/
Researchers from the University of Alabama at Birmingham and University of California at San Francisco analyzed marijuana and tobacco use among 5,000 black and white men from the national database, CARDIA (Coronary Artery Risk Development in Young Adults study), which was intended to determine heart disease risk factors over a 20-year period.
Measuring participants’ lung function for air flow and lung volume five times throughout the study period, the researchers found that cigarette smokers saw lung function worsen throughout the 20-year period, but marijuana smokers did not. Only the heaviest pot smokers (more than 20 joints per month) showed decreased lung function throughout the study.
“The more typical amounts of marijuana use among Americans are occasional or low levels,” said Dr. Stefan Kertesz, assistant professor of medicine at the University of Alabama at Birmingham and principle investigator of the study. “From the standpoint of being a scientist, these data suggest that low and moderate range use of marijuana do not do long-term harm.””
Read more: http://abcnews.go.com/Health/smoking-pot-harm-lung-function-time/story?id=15331989
“Researchers from UAB helped conduct a 20-year study designed to measure heart disease, but it’s getting international publicity because of what it means for moderate marijuana use and lung function.
Researchers studied low to moderate marijuana users, those who reported smoking about two to three times per month. With cigarette smoking, the more you smoke, the more you decrease your lung function.
This study, published in the Journal of the American Medical Association shows with marijuana, it’s a much more complicated relationship.
Stefan Kertesz with the UAB School of Medicine says, “There was actually an increase in air flow and an increase in lung capacity, but not enough that a person would necessarily feel healthier.”
Dr. Kertesz says it’s important to emphasize the smokers in the study are not the heavy duty smokers often portrayed in movies. Researchers weren’t able to draw conclusions on the effects of heavy marijuana use and lung function.
He says it’s possible the very small increase in air flow researchers saw could represent something of a practice effect. Marijuana smokers are used to taking in deep breaths, holding it and breathing out, which could help them ace the office test of lung function.”
“Add one more data point to the decades-old debate over marijuana legalization: A new study concludes that casual pot smoking – up to one joint per day – does not affect the functioning of your lungs.”
“The study, published in the Jan. 11 edition of Journal of the American Medical Association, also offered up a nugget that likely will surprise many: Evidence points to slight increases in lung airflow rates and increases in lung volume from occasional marijuana use.”
Read more: http://www.cbsnews.com/8301-205_162-57356548/study-no-lung-danger-from-casual-pot-smoking/
“People who occasionally smoke marijuana do not suffer long-term lung damage the way cigarette smokers do, and may actually experience a slight improvement, a 20-year US study has revealed.”
“Since the research included more than 5,000 people over a long time span, the authors said it should help clear up some of the confusion about the risks of marijuana smoking, which is increasingly common in the United States.”
Read more: http://health.msn.co.nz/healthnews/8401956/no-lung-damage-from-marijuana-study
“Unlike the cigarette habit, occasional pot smoking does not seem to trigger declines in lung function that could lead to breathing problems, a new 20-year study suggests.
“Tobacco takes you down that road toward breathlessness, but low to moderate levels of marijuana don’t,” said study co-author Dr. Stefan Kertesz.”
Read more: http://healthyliving.msn.com/diseases/cancer/occasional-pot-smoking-wont-harm-lungs-study-3
“Periodically smoking marijuana doesn’t appear to hurt lung capacity, the largest study ever conducted on pot smokers has found.”
“This is a well-done study involving more subjects than in the past,” says Tashkin, who is not affiliated with the new study. “The public should take away it’s a confirmatory study, but larger and longer than previous studies demonstrating, once again, that smoking marijuana does not impair lung function, unlike tobacco.”
“Smoking a joint once a week or a bit more apparently doesn’t harm the lungs, suggests a 20-year study that bolsters evidence that marijuana doesn’t do the kind of damage tobacco does…
The analyses showed pot didn’t appear to harm lung function, but cigarettes did…”
Read more: http://www.foxnews.com/health/2012/01/11/marijuana-doesnt-appear-to-harm-lung-function-study-finds/
“The active compound in herbal cannabis, Delta(9)-tetrahydrocannabinol, exerts all of its known central effects through the CB(1) cannabinoid receptor. Research on cannabinoid mechanisms has been facilitated by the availability of selective antagonists acting at CB(1) receptors and the generation of CB(1) receptor knockout mice. Particularly important classes of neurons that express high levels of CB(1) receptors are GABAergic interneurons in hippocampus, amygdala and cerebral cortex, which also contain the neuropeptides cholecystokinin. Activation of CB(1) receptors leads to inhibition of the release of amino acid and monoamine neurotransmitters. The lipid derivatives anandamide and 2-arachidonylglycerol act as endogenous ligands for CB(1) receptors (endocannabinoids). They may act as retrograde synaptic mediators of the phenomena of depolarization-induced suppression of inhibition or excitation in hippocampus and cerebellum. Central effects of cannabinoids include disruption of psychomotor behaviour, short-term memory impairment, intoxication, stimulation of appetite, antinociceptive actions (particularly against pain of neuropathic origin) and anti-emetic effects. Although there are signs of mild cognitive impairment in chronic cannabis users there is little evidence that such impairments are irreversible, or that they are accompanied by drug-induced neuropathology. A proportion of regular users of cannabis develop tolerance and dependence on the drug. Some studies have linked chronic use of cannabis with an increased risk of psychiatric illness, but there is little evidence for any causal link. The potential medical applications of cannabis in the treatment of painful muscle spasms and other symptoms of multiple sclerosis are currently being tested in clinical trials. Medicines based on drugs that enhance the function of endocannabinoids may offer novel therapeutic approaches in the future.”
“The endocannabinoid system, including its receptors (CB(1) and CB(2)), endogenous ligands (‘endocannabinoids’), synthesising and degrading enzymes, as well as transporter molecules, has been detected from the earliest stages of embryonic development and throughout pre- and postnatal development. In addition, the endocannabinoids, notably 2-arachidonyl glycerol, are also present in maternal milk. During three distinct developmental stages (i.e. embryonic implantation, prenatal brain development and postnatal suckling), the endocannabinoid system appears to play an essential role for development and survival. Thus, during early pregnancy, successful embryonic passage through the oviduct and implantation into the uterus both require critical enzymatic control of optimal anandamide levels at the appropriate times and sites. During foetal life, the cannabinoid CB(1) receptor plays a major role in brain development, regulating neural progenitor differentiation into neurones and glia and guiding axonal migration and synaptogenesis. Postnatally, CB(1) receptor blockade interferes with the initiation of milk suckling in mouse pups, by inducing oral motor weakness, which exposes a critical role for CB(1) receptors in the initiation of milk suckling by neonates, possibly by interfering with innervation of the tongue muscles. Manipulating the endocannabinoid system by pre- and/or postnatal administration of cannabinoids or maternal marijuana consumption, has significant, yet subtle effects on the offspring. Thus, alterations in the dopamine, GABA and endocannabinoid systems have been reported while enhanced drug seeking behaviour and impaired executive (prefrontal cortical) function have also been observed. The relatively mild nature of the disruptive effects of prenatal cannabinoids may be understood in the framework of the intricate timing requirements and frequently biphasic effects of the (endo)cannabinoids. In conclusion, the endocannabinoid system plays several key roles in pre- and postnatal development. Future studies should further clarify the mechanisms involved and provide a better understanding of the adverse effects of prenatal exposure, in order to design strategies for the treatment of conditions such as infertility, mental retardation and failure-to-thrive.”