I agree with the premise, but I would adjust the belief that marijuana is inherently unhealthy. The government didn't classify it as Schedule I because it was unhealthy. Marijuana is now being studied in universities in our country and could introduce a bevy of treatments for disorders that pharmaceuticals cannot palliate.
On the same token, there are some very nascent studies investigating the effects of low-dose nicotine as a stimulant and the possible positive effects on the body as a stimulant in the same way that caffeine has been shown to provide a boost. With the burgeoning e-cigarette market, people are getting their nicotine fix while saving their bodies from the deleterious effects of smoked tobacco.
And let's not forget that alcohol, obviously in moderation, has been shown to improve some bodily functions and has been linked to cardiovascular health, at least specifically with red wine.
As with anything: alcohol, food, marijuana... everything in moderation.
Points taken. I think we’re in agreement on this issue for probably many reasons.
Respiratory Effects of Marijuana
Marijuana smoke smoke contains a similar range of harmful chemicals to that of tobacco smoke (including bronchial irritants, tumor promoters and carcinogens) (Hoffmann et al, 1975). As inhaled smoke comes into contact with airway and lung before being absorbed into the bloodstream, it is likely to affect the respiratory system (Novotny et al, 1982).
Risk of respiratory effects from inhaling marijuana smoke are heightened by the more intensive way in which marijuana is smoked -- when smoking marijuana compared to tobacco, there is a prolonged and deeper inhalation and it is smoked to a shorter butt length and at a higher combustion temperature. This results in approximately 5 times the carbon monoxide concentration, 3 times the tar, and the retention of one-third more tar in the respiratory tract. Higher levels of ammonia and hydrogen cyanide have also been found in marijuana smoke, compared to tobacco (Moir, et al., 2008; Wu et al., 1988; Tashkin et al., 1991; Benson & Bentley, 1995).
A 2011 systematic review of the research concluded that long-term marijuana smoking is associated with an increased risk of some respiratory problems, including an increase in cough, sputum production, airway inflammation, and wheeze – similar to that of tobacco smoking (Howden & Naughton, 2011). However, no consistent association has been found between marijuana smoking and measures of airway dysfunction. Occasional and low cumulative marijuana use has not been associated with adverse effects on pulmonary function (Pletcher et al., 2012); the effects of heavier use are less clear.
Additionally, many marijuana smokers also smoke tobacco, which further increases the harm. Numerous studies have found that the harmful effects of smoking marijuana and tobacco appear to be additive, with more respiratory problems in those who smoke both substances than in those who only smoke one or the other (Wu et al, 1988).
The association between smoking marijuana and lung cancer remains unclear. Marijuana smoke contains about 50% more benzopyrene and nearly 75% more benzanthracene, both known carcinogens, than a comparable quantity of unfiltered tobacco smoke (Tashkin, 2013). Moreover, the deeper inhalations and longer breath-holding of marijuana smokers result in greater exposure of the lung to the tar and carcinogens in the smoke. Lung biopsies from habitual marijuana-only users have revealed widespread alterations to the tissue, some of which are recognized as precursors to the subsequent development of cancer (Tashkin, 2013).
On the other hand, several well-designed and large-scale studies, including one in Washington State (Rosenblatt et al, 2004), have failed to find any increased risk of lung or upper airway cancer in people who have smoked marijuana (Mehra et al, 2006; Tashkin, 2013), and studies assessing the association between marijuana use and cancer risk have many limitations, including concomitant tobacco use and the relatively small number of long-term heavy users – particularly older users. Therefore, even though population-based studies have generally failed to show increased cancer risk, no study has definitively ruled out the possibility that some individuals, especially heavier marijuana users, may incur an elevated risk of cancer. This risk appears to be smaller than for tobacco, yet is important to know about when weighing the benefits and risks of smoking. (Tashkin DP, 2013). More research on marijuana smoking and cancer is needed. -