This is a hand-rolled tobacco cigarette. No illegal drugs were used in this photo.
Image: Flickr/cagrimmett
-
The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
Read More »
It wouldn't have mattered if Bill Clinton inhaled, as far as his lungs are concerned. Smoking up to a joint per day doesn't seem to decrease lung function, according to a study published in Jan. 11 edition of Journal of the American Medical Association.
In fact, occasional marijuana use was associated with slight increases in lung airflow rates and increases in lung volume, the study found.
Far from a license to light up, the study eases the worry among some health professionals that daily use of marijuana for medical reasons could have negative, long-term implications on pulmonary health.
The study, led by Mark Pletcher of the University of California, San Francisco, compared the effects of both cigarette and marijuana smoking over a period of 20 years in a group of more than 5,000 adults, part of a longitudinal study called Coronary Artery Risk Development in Young Adults (CARDIA).
The data revealed nothing new about tobacco: As exposure to tobacco goes up, lung capacity in terms of the amount of air a smoker can exhale goes down. It's a linear relationship.
Not so with marijuana. More pot smoking was associated with increases in lung capacity up to a level equivalent to about one joint per day for seven years or one joint per week for up to 49 years. Only at levels of marijuana smoking higher than this did the researchers see a leveling off and then potential reversal of this relationship to improved lung capacity.
The increase in lung function at low levels was very small, said study researcher Stefan Kertesz, a professor of preventive medicine at the University of Alabama, Birmingham. It was about 50 milliliters, or the size of a kid's juice box.
The researchers don't know why light-to-moderate pot use might subtly improve lung function. It could be that marijuana users inadvertently train themselves to be good at the inhalation and exhalation test because they "practice" deep breathing when they smoke pot, Kertesz told LiveScience. The airflow increase, then, is not necessarily an indicator of healthier lungs.
At higher levels, this tiny increase seems to disappear and lung function may decrease, Kertesz said. The study included few heavy users, which may be one key to why pot smoking isn't as harmful as tobacco smoking.
"A marijuana smoker might have a few joints a month, or a small number of joints or pipe bowls a day," Kertesz said. "That's never going to be quite as much smoke as a tobacco smoker with a half-a-pack, pack-a-day or two packs-a-day habit." [Infographic: Who Still Smokes?]
But before you start lighting up, do remember you have other body parts. The main active chemical in marijuana is delta-9-tetrahydrocannabinol, or THC. THC travels to the brain, producing that high. The long-term effects of THC are uncertain, but most health professionals don't consider THC to be benign.
Chronic marijuana use has been associated with anxiety, schizophrenia, bipolar disorders and depression. As reported earlier this month in the journal Archives of General Psychiatry, THC may trigger psychosis by interfering with the brain's ability to distinguish between important and unimportant stimuli that constantly flood the various regions in the brain.
See what we're tweeting about
38 Comments
Add CommentAll of the psychological disorders that were listed that are associated with marijuana use only occur in a small minority of marijuana users with the exception of temporarily impaired memory. They also haven't proven that any of those effects are permanent, at least, not that i know of. Not that I'm saying that marijuana doesn't have ANY harmful affects.
Reply | Report Abuse | Link to thisI am sorry, but this study is unbelievable. This study says nothing about increases in lung cancer rates, due to smoking marijuana - only lung volume.
Reply | Report Abuse | Link to thisFact: marijuana has 4x the amount of tar as one cigarette. Tar is causally linked to an increase in lung cancer.
There is every reason to believe that smoking marijuana will raise your risk of lung cancer.
Marijuana smokers always like to claim that there are no dangers in smoking pot. The study was performed by a researcher at UCSF - a city with probably one of the most liberal stances to marijuana in the US. This researcher's views are highly suspect to be biased.
While I am not against marijuana in general, you are in utter denial if you believe that there is no increased cancer risk by inhaling tar and alveoli cauterizing ash into your lungs for decades. If you have ever seen someone hacking their lungs out from "smokers cough" or struggling to run a mile as a teenager, because they were chronic smokers, you know this is unbelievable.
THC in a time release capsule or pill form may prove beneficial to some people, but constantly smoking anything is inherently dangerous.
Reply | Report Abuse | Link to thisConcerned citizen doesn't know what it's talking about. Likely he is a PR flak from big Pharma who are scared just how good pot is to replace many medicines and alcohol with far less side effects.
And studies were done on pot and lung, other cancers and was shown to be protective instead.
Marijuana is the safest drug with actual benefits for the user as opposed to alcohol which is dangerous, causes addiction, birth defects, and affects literally every organ in the body. Groups are organizing all over the country to speak their minds on reforming pot laws. I drew up a very cool poster featuring Uncle Willie Nelson and The Teapot Party for the cause which you can check out on my artist’s blog at http://dregstudiosart.blogspot.com/2011/01/vote-teapot-2011.html Drop in and let me know what you think!
Reply | Report Abuse | Link to thisThere is only one important thing to remember about this topic. It is .....squirrel! Did you see the squirrel run by... my door needs painting.
Reply | Report Abuse | Link to thisI need a pizza....
It numbs the brain so that really BAD behavior becomes NOT really a problem. Yep, it's a real brain enhancement for stupid!
Reply | Report Abuse | Link to thisThe real argument against marijuana is that it makes you lazy and unproductive. There's zero reason it should be illegal as it's less harmful than alcohol, but we shouldn't act like it has no negatives either. Like any drug - it is best enjoyed responsibly. Not while on the job, but during free time when it's none of Uncle Sam's business what people do, so long as it doesn't hurt others (and smoking marijuana doesn't!).
Reply | Report Abuse | Link to thisAnything that you enjoy must be bad for you, no?
Reply | Report Abuse | Link to thisLet us not forget that even the air we breathe is toxic. The lesson here is one of moderation.
Having full knowledge of the effects of very long term marijuana usage and the lung enhancing effects I can concur with these findings.
Reply | Report Abuse | Link to thisHowever, I feel for all those Republicans, both past and present, who now have been "outed" as total liars and propagandists------just what is a lying scumbag traitor to America to do in light of all this honesty?
When addiction talks, intelligence walks.....
Reply | Report Abuse | Link to thisFact: soft drugs are legal for several decades in the Netherlands. Netherlands have less crime and much longer life expectancy than USA.
Reply | Report Abuse | Link to thisSo, there is an empirical proof that penalization of soft drugs is pointless prejudice. Much like countries in Middle Ages penalized heart surgery and dissection as close to grave robbing.
@ the authors - "Chronic marijuana use has been associated with anxiety, schizophrenia, bipolar disorders and depression."
Reply | Report Abuse | Link to this- Let's make sure we don't confuse correlation with causality. Rather than pot causing these disorders, it's just as likely (if not more so) that people who already have them are using pot as a form of self-medication.
@ ConcernedCitizen - "Fact: marijuana has 4x the amount of tar as one cigarette. Tar is causally linked to an increase in lung cancer."
-That still means that a 1-joint-a-day pot smoker is getting less than half of the tar exposure that a half-pack-a-day cigarette smoker is.
@Bops - "The article is a big lie. People, that I knew from the past, who smoked... are still 'Crazy Mavericks'".
- How much were they smoking? The article very clearly states that any benfits were observed ONLY in low-level smokers.
I have never heard that there was beneficial effects on the lungs. That said, it stands to reason that people who inhale less smoke will have less problems. In fact, I have NEVER heard of any casual pot smoker getting lung cancer from their ritual. Without smoking cigarettes,or being around heavy cigarette smokers that is. I am all for the legalization of marijuana. I am sure that many people, who have been fooled by the propaganda surrounding this topic for several decades, will be unwilling to accept that they have been duped. They really only need to look at the origins of these laws and the pseudo-scientific studies they used to scare people. Look it up if you like. Racism fueled this legal maneuver. Sounds too ridiculous? I know! But true.
Reply | Report Abuse | Link to thisSort of like alcohol, right? Look up the statistics before making ignorant comments please. If you can find even one documented case of death from overdose or directly linked complications due to marijuana smoking I'll be shocked. However, in the time it's taken me to write these few sentences, multiple people have died from alcohol poisoning and alcohol related complications. More people still, have died from DUI and moronic drunken arguments. Alcohol poisoning alone kills almost as many people every year as the combined death rate from ALL illicit drugs. Yes, ALL! I don't think we need to legalize crack or methamphetamines, but clearly there are ulterior motives at work when the only legal intoxicant is also, hands down, the most dangerous.
Reply | Report Abuse | Link to thisI have a degree in herbal medicine from the School of Natural Healing and I am positive that marijuana's medical benefits outweigh any negative side effects it has and it was a very bad idea and an ill informed decision to make it illegal. Tobacco has good medical benefits too when it is not abused. That is the key to the success of healing; do not abuse the medication.
Reply | Report Abuse | Link to thisJust out of curiosity, has anyone ever considered the potential tax benefits of legalizing marijuana? The figures that we see on television, in terms of the "street value" of a given bust, would seem to indicate that, as a legal commodity, pot would have a substantial tax value. Hundreds of millions, if not billions of dollars in tax revenue are being squandered every year, and for what? Nothing more than an archaic and outmoded way of thinking, that's what. No genuine scientific research that has ever been conducted has established marijuana as a "dangerous" drug. The only negative research I have ever personally encountered was done by government or corporate shills, willing to prostitute their scientific credibility for a few bucks. And all of it was debunked by the empirical findings of other scientists. If anybody is interested in learning more about one of the most extraordinary plants on Earth, check out "The Emperor Wears No Clothes" by Jack Herer. This book is not about being a pot smoker. It is about the total benefit of utilizing an amazing plant. Who's tired of paying $3.50/gallon for gas? Who's tired of fighting wars for oil? Grow hemp. Who's tired of non-biodegradable plastics? Grow hemp. Who's tired of watching forests get cut down to make notebook paper? Grow Hemp! These are just a few of the advantages to industrial scale hemp production. Check it out. If you like what you read, share it with a friend and contact your government representatives. Let them know what you think. That we are getting screwed as a culture and a country, all so a few obscenely wealthy families can continue getting richer.
Reply | Report Abuse | Link to thisDennis Hill, Biochemist & Cancer researcher for many years, used Cannabis oil (a.k.a Rick Simpson oil) to cure his stage 4 prostate cancer.
Reply | Report Abuse | Link to thisAs a Biochemist, Dennis knows his stuff, and gives a basic run down of the many ways in which THC & CBD work.
http://web.me.com/dbhill/cure/Endocannabinoid_System.html
http://web.me.com/dbhill/cure/How_It_Works.html
"It is known that THC and CBD are biomimetic to anandamide, that is, the body can use both interchangeably. Thus, when stress, injury, or illness demand more from endogenous anandamide than can be produced by the body, its mimetic exocannabinoids can be administered. If the stress is transitory, then the treatment can be transitory. If the demand is sustained, such as in cancer, then treatment needs to provide sustained pressure of the modulating agent on the homeostatic systems. This is why Rick Simpson recommends twice daily doses of hemp oil extract (C. indica), for three months, in the case of cancer.
Typically CBD gravitates to the densely packed CB2 receptors in the spleen, home to the body’s immune system. From there, immune cells seek out and destroy cancer cells. Interestingly, it has been shown that CBD cannabinoids have the ability to kill cancer cells directly without going through immune intermediaries. CBD hijacks the lipoxygenase pathway to directly inhibit tumor growth.5 As a side note, it has been discovered that CBD inhibits anandamide reuptake. This means that cannabidiol helps the body preserve its own natural endocannabinoid by inhibiting the enzyme that breaks down anandamide.
Coincidentally, it is not only CBD that is specifically cytotoxic to cancer cells, THC takes a different approach the task:
THC achieves this wizardry by binding to protein receptors on a cancerous cell’s surface. Once attached, the THC induces the cell to make a fatty substance called ceramide, which prompts the cell to start devouring itself. “We see programmed cell death,” Velasco says. What’s more, noncancerous cells don’t make ceramide when they come into contact with THC. The healthy cells don’t die."
Endogenous ceramide’s day job is to speed destruction of already stressed or senescent cells. We seen now that in the presence of THC, ceramide senses cancer cells as stressed or senescent, thus speeding their death."
Just WOW!
Have you ever read Scientific American? I mean REALLY read it...
Reply | Report Abuse | Link to thisThe active products in cannabis are highly fat-soluble, and thus do accumulate for a long time in body tissues with a high fat content, for example the brain. In dogs, after a not too long period of Cannabis dosing, changes in the EEG of deep brain structures remain years after dosing was discontinued,and deep brain structures are the ones that rule memory and instincts, and act as a general organizer for the whole brain activity. All these drugs were initially in the market without bought restrictions, and banning started when the harm from drugs of abuse begun to be realized. In China, when the britons had the monopoly of opium sales, there were 5 million addicts or more, but Cannabis is not the same kind of thing as opiates, even when Cannabis it's also very dangerous. It will be no problem allowing people with non-curable forms of cancer using Cannabis as a relievemnt for some kind of nuisances, but for the rest, there is no reason why to legalize this. A peculiar book on Cannabis is "The book of grass. An anthology of indian hemp",G. Andrews and S. Vinkenoog eds. It contains a surprising short literary piece in a wording style close to the one in the St John's Apocalypse, that is supposed to be linked to some forms of eastern mystic cultures.
Reply | Report Abuse | Link to thisThe french word assasin comes from hashich, some ancient turkish contract-murderers used Cannabis to help them in killings, and some tribes used Amanita muscaria, a mushroom with a very narrow window between "high" and heart rhythm problems connected death,it was taken before combats by siberians and vikings, as it produced aggressiveness and an increased muscle tone. This was probably the "Magic potion" in the french comic characters by Uderzo.
Your remark is irrational in several ways.
Reply | Report Abuse | Link to thisBanning pot began because it was associated with immigrant Mexicans and could be used as a pretext to persecute and expel them. This had nothing to do with pharmecological effects which are far less harmful than alchohol or tobacco smoking
Pot is not physically addictive. People genuinely resort to it to releave otherwise safely untreatable conditions such as bi-polar syndrome, depression, cancer-drug related nausea, chronic pain, and pathologic anxiety.
Your references to "St John's Apocalypse", opium adicts, Turkish contract murderers, and (wildly off-topic) "Amanita muscaria", suggests that you are far more delusional than any pot user's high.
Is this the kind of reasoning that is used to justify ruining thousands of Americans lives with arrest and criminal records, and even sending thousands of Americans to jail each year?
My opinion is that cannabis should be legalized and taxed heavily, just like tobacco and alchohol.
Reply to SteveinOG: pot was made illegal early in the XXth century, long time before the mexican rush to the USA started to be a nuisance, or even noticeable. I had in the 70's a discussion with a member of the communist party that stated that there's no difference between psychological and physical addiction, as psychological addiction has a physical neurological correlate too; he was right, but drugs with a physical withdrawal syndrome de produce measurable physical effects when the addict is weaned, and others don't. I was told by a doctor about a case of a recruit developing suspiciousness and paranoia after pot discontinuation, symptoms that faded when he got a new dose. The reference to St John's Apocalypse was not to St John's Apocalypse but to a shamanistic text in the book by Andrew and Vinkenoog, that is worth reading. Just the similarity in literary style between the two texts was remarkable for me. If you read my text, I just added some facts pointing that pot is a dangerous drug. The etymology of the french word assassin having a connection to hashish is nothing but the truth. Today there is enough evidence to show anybody that pot use has many serious dangers, may be it doesn't hit everybody but that's all. You use the word delusional: I'm sorry, I didn't know you were an MD, but what I'm sure about, is that I've never applied for an appointment in your office, that insults are a tipifyed offense, and also divulgation of personnal data, such a diagnosis, is one. Please refrain from that kind of things. May be I have enough observational data about drug effects to make the affirmations I did, I don't want to disclose personnal information. Cannabis active molecules are hallucinogens, and for example, Sandoz past decades trying to find a medical use for LSD - Delisyn, they called it - another hallucinogen, and failed. In some severe diseases, Cannabis can be useful, for for widespread recreational use, it's too dangerous, if I were in the position to make the decision about legalizing pot, I'll say "Nay". An arab phrase: "A little bit hash warms, too much burns". A joke: three pot users, one inhales and says: "I'm going to buy the island Manhattan", the second inhales too: "I'm going to buy the federal reserve", the third one inhales more deeply and says: "I don't sell, guys, I don't sell". Salut +
Reply | Report Abuse | Link to this1) Tobacco is cancer causing largely because it delivers specific carcinogens such as NNK and NNAL that are not present in cannabis. Not all "tar" is created equal, and tobacco has some of the most carcinogenic types of tar known to science, whereas cannabis does not.
Reply | Report Abuse | Link to this2) Cannabis (marijuana) use is associated with a DECREASE in several types of cancer... potentially even providing a protective effect against tobacco and alcohol related cancer development.
Donald Tashkin, a UCLA researcher whose work is funded by NIDA, did a case-control study comparing 1,200 patients with lung, head and neck cancers to a matched group with no cancer. Even the heaviest marijuana smokers had no increased risk of cancer, and had somewhat lower cancer risk than non-smokers (tobacco smokers had a 20-fold increased lung cancer risk). Tashkin D. Marijuana Use and Lung Cancer: Results of a Case-Control Study. American Thoracic Society International Conference. May 23, 2006.
Researchers at the Kaiser-Permanente HMO, funded by NIDA, followed 65,000 patients for nearly a decade, comparing cancer rates among non-smokers, tobacco smokers, and marijuana smokers. Tobacco smokers had massively higher rates of lung cancer and other cancers. Marijuana smokers who didn't also use tobacco had no increase in risk of tobacco-related cancers or of cancer risk overall. In fact their rates of lung and most other cancers were slightly lower than non-smokers, though the difference did not reach statistical significance. Sidney, S. et al. Marijuana Use and Cancer Incidence (California, United States). Cancer Causes and Control. Vol. 8. Sept. 1997, p. 722-728.
Why do abusers of narcotics want science to justify bad behavior? Have you ever smelled burning grass? Do your friends wear sunglasses at midnight? There are some obvious effects from smoking pot.
Reply | Report Abuse | Link to thisDon't tell me what it doesn't do. Tell me what it does. I would like to see the data that produced these results. It smells like a Onion News Net story.
If it is good for you, then the Doc should write you a prescription. I asked a friend why he smoked and he said "my friends made me do it."
It may have been led by a researcher from UCSF, but I noted that the quoted researcher was at the University of Alabama in Birmingham. UAB hardly qualifies as a liberal bastion; I know, I graduated from there.
Reply | Report Abuse | Link to thisAddiction is a function of the "reward circuit" in your brain. While not fully understood we do know that it tends to be triggered by a pleasurable experience. Addiction seems most likely to occur when this circuit is over stimulated. This is a highly individual reaction as everyone reacts differently to every drug or other pleasurable experience. Something like Skinners "operant conditioning" seems to play a role also.
Reply | Report Abuse | Link to thisSo, some people can use a given drug or engage in another addictive behavior (gambling, sex) without it becoming a problem while another person doing the same thing becomes addicted. Also, a person may use a given drug without a problem but become addicted to another drug or activity.
How do you know what is a danger to you? I can't prove this from formal research but nearly 40 years as an addictions counselor leads me to believe that the more reward you get out of your initial or early use the more dangerous that drug or activity is for you.
And if you accept the definition of addiction as experiencing continuing problems in a major area of your life as a result of your use and yet you continue to use then yes, marijuana can be an addictive drug. I've worked with many who have lost careers, marriages, homes and other major possessions as a result of marijuana use and are still smoking when they end up in treatment. That's addiction. (For a more formal description of dependence see the DSM IV TR).
As far as lung problems, I would ask Concerned Citizen to document his or her assertion that marijuana causes cancer. I've always suspected that it might but can remember no definitive research on that subject. Can you direct us to such a published study? I would appreciate it.
One must forever take with more than a grain of salt the assertions of those who are compensated by the anti-drug industry.
Reply | Report Abuse | Link to thisTheir assertions do not map well onto reality.
If someone is making a living providing "addiction counseling" s/he has a vested interest in convincing the rest of the general public they are of some great worth. Hence, they love to spread scare stories.. which are rarely backed up by the "studies" they claim support their views. Few of them have even read the original research, much less understood it. They rely upon little more than rumors they heard in their subculture and believe them since they coincide with their prejudices.
Compensation take many forms.. the most obvious is money.. but, social standing is equally, if not more, important once basic needs are met.
The anti-drug industry has been on a fools errand for decades upon decades... and they seek to drag the rest of us along on their fantasy-laden trek.
You can pretty much disregard the assertions of those whose living depends upon cannabis remaining illegal... they will do or say anything in order to continue to gain the various forms of compensation they get now.
The sad truth is that there is nothing of any substance to back up the anti-cannabis folks' cult-like beliefs... and the real world belies them at every turn.
If someone stands to lose an easy living where they also get to lord to over "clients" as a sort of authority figure... you can doubt their motives..and should.
This is the sad problem we see now.
For some legitimate research and ideas check out what LEAP.. Law Enforcement Against Prohibition has to say.
The writer couldn't help himself but try to continue to demonize cannabis.
Reply | Report Abuse | Link to thisGod forbid he should cite the study as reported in SA that after age 25 cannabis has positive effects on the brain: anti-dementia, mitigates memory loss, is protective of the mature brain.
The reality is illicit drug users, and cannabis users in particular are the victims of persecution. When a society legally allows the havoc alcohol causes, while criminalizing other far less dangerous drugs, it is one group enforcing their moral values on others. This is persecution.
How much better society would be if no one drank alcohol but everyone used cannabis.
Keep up with the science. What you say is what one would expect but it is not what is happening in the real world. Obviously there is chemistry involved with cannabis that mitigates said lung damage.
Reply | Report Abuse | Link to thisOnce again we are seeing the negative results of criminalization that impedes scientific research. Criminalization of drugs as having NO MEDICAL OR OTHER BENEFITS has prevented some incredibly valuable and fascinating research. For example why does the human body produce the super psychedelic DMT and 5-MEO-DMT?
Why are you blaming Republicans?
Reply | Report Abuse | Link to thisWhat are you addicted to? Nothing? Check again.
Reply | Report Abuse | Link to thisAbout a billion a year but I forget if that was just California or all of America
Reply | Report Abuse | Link to thisbut for the rest, there is no reason why to legalize this
Reply | Report Abuse | Link to thisYES THERE IS A VERY GOOD STAND ALONE REASON: TO STOP THE PERSECUTION.
THERE IS MORE EMOTIONAL TRAUMA EXPERIENCED BY CANNABIS USERS AND THEIR CIRCLE OF FRIENDS THAN SAY THE EMOTIONAL TRAUMA EXPERIENCED BY WOMEN AND THEIR FRIENDS IF WOMEN WERE ONCE AGAIN DENIED THE RIGHT TO VOTE.
FOR YOU TO NOT BE A HYPOCRITE I ASSUME YOU SUPPORT THE PROHIBITION OF ALCOHOL? IF NOT WHY NOT? BECAUSE??? THE LAW IS UNENFORCEABLE? BUT MARIJUANA LAWS ARE WORKING?
USE A VAPORIZER...NO SMOKE THEN
Reply | Report Abuse | Link to thisHaving smoked marijuana for over half a century, I am happy to report that a recent chest xray showed no abnormalities and as my relatives will attest, no diminution of cognitive abilities or memory. Also the use of the term "high" to describe the result of inhaling marijuana smoke, with it's manic association is misleading. It would be more accurate to say "cheerful" or "contented".
Reply | Report Abuse | Link to thisVery disapointing article. Got the facts about the cardiopulmanary effects seen in the study right, but just about everything else wrong. There are numerous active ingredients. The boogeyman the authors paints with paranoia, THC is being studied as a molecule which may protect brains from Alzheimer's. The ratio of the 2 primary active ingredients is the causative factor in memory loss, and the suspicion that pot causes psychosis has yet to be demonstrated. What has been demonstrated is that use of pot actualy has a protective effect against some forms of cancer. Though to be fair, I find it hard to believe that there is NO downside to burning plant matter and inhalling it - particulate matter, tar and carbon monozide not being particularly good for human health.
Reply | Report Abuse | Link to thisMarijuana contains 4 times more tar than cigarettes. Fine. But you haven't given the volume of MJ smoked. A pack of cigarettes (a day's worth for a lot of smokers) contains about .75 ounces of tobacco. If I had a .75 ounce stash of marijuana, it would last me about six weeks. That's 42 packs of cigarettes. At that rate, my personal use would put your number quite a bit lower. You'd have to say something like, "Consuming marijuana at a rate of 10 hits per day to remain high from sunup to sundown delivers 10.5 times less tar than consuming a pack of cigarettes a day." Now you have an honest number.
Reply | Report Abuse | Link to thisAre you trying to imply that marijuana smoking is more dangerous than cigarette smoking? You'll have to try harder than that.
I have to correct this comment. The study you are referring to about marijuana leaves containing more tar than tobacco leaves is true; BUT only an idiot would try to smoke a marijuana leaf...
Reply | Report Abuse | Link to thisThe smoking portion of the plant is the plants' flower also known as the "bud". A joint of marijuana contains significantly less tar than than a cigarette of tobacco. The amount of tar in a joint of marijuana is so insignificant that it's actually not dangerous to your lungs, actually quite the opposite. Marijuana has been proven to increase lung performance and improved lung capacity.
Let's try educating ourselves before coming off as stereotypical ignorant people.
http://www.scientificamerican.com/article.cfm?id=casual-marijuana-smoking
didnt hurt michael phelps a whole lot
Reply | Report Abuse | Link to this