Marijuana smoking may increase stroke risk for young adults

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Marijuana may trigger strokes in young adults, according to preliminary research presented today at an international medical conference.

New Zealand researchers reviewed urine samples taken from 160 stroke sufferers between the ages of 18 and 55, and discovered the patients were more than twice as likely to have pot, or cannabis, in their system.

"Cannabis has been thought by the public to be a relatively safe, although illegal substance," study author Dr. P. Alan Barber, professor of clinical neurology at the University of Auckland in New Zealand, said in a statement to the American Heart Association. "This study shows this might not be the case; it may lead to stroke."

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Marijuana is the most commonly used illicit drug in the United States, taken by 7 percent of Americans according to a 2012 government survey.

The drug is illegal in the United States on a federal level, however, Washington and Colorado became the first states to pass laws legalizing recreational pot use last November. Eighteen states plus the District of Columbia also have laws permitting the use of medical marijuana.

In what they call the first case-controlled study to find a link between marijuana use and strokes, researchers enlisted 150 patients who had an ischemic stroke and 10 who had a transient ischemic attack (TIA).

Strokes, or brain attacks, are caused by disruptions of blood flow to the brain. About 85 percent of strokes are ischemic, meaning they are caused by blood clots or plaque deposits in linings of blood vessels that stop blood flow to the brain. That's different from a less-common hemorrhagic stroke that occurs when a blood vessel in the brain bursts. Symptoms of strokes include severe headache, sudden numbness or weakness of the face or limbs, sudden confusion or trouble speaking, vision problems, dizziness and loss of coordination.

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People may also experience a TIA, also called a "mini" or "warning" stroke, a temporary blockage that causes stroke symptoms that go away after a few minutes without causing lasting damage. About one-third of people who have a TIA go on to have a stroke within a year, according to the American Heart Association.

The researchers found 16 percent of the subjects who went to the hospital following a stroke episode had marijuana in their system, compared to 8.1 percent of control subjects who came to the hospital. Barber adds there have been case reports of people with no other vascular risk factors having a stroke or TIA hours after using marijuana.

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However, all but one of the stroke patients who had marijuana in their urine also used tobacco. Barber still believes the marijuana was the culprit.

"For starters, this is a young age group to be having strokes, and many didn't have any of the traditional risk factors. And some patients had a stroke while actually smoking cannabis," he told EverydayHealth. "We know cannabis can cause changes in blood pressure and heart rate that are associated with increased stroke risk. Importantly, it can also cause heart palpitations, [a sign of atrial fibrillation]. And atrial fibrillation is very strongly associated with stroke," he added.

Every year more than 795,000 Americans have a stroke, 610,000 who have one for the first time. About 130,000 Americans die from a stroke each year, about one death every four minutes.

The study was presented Feb. 6 at the American Stroke Association's International Stroke Conference in Honolulu.

[Kathiezzzz]

As the comments state there are flaws in this study. It is another study done in a retrospective look at health. Again the timing of the article is not a coincidence for sure. Using the media to influence the uneducated on this issue to vote their way. There are so many issue with cannabis that are not being looked at here. The health effects need to be researched and there are many fine studies going on. An example is at UCSD's Center for Medicinal Cannabis Research who have studies paid for by the state of CA. But until we open people's minds to look beyond the rhetoric of the past lies and propaganda and look at the science and use common sense to make reasonable laws to regulate it's uses. As a retired pediatric oncology RN I have a unique perspective to look at this issue. I feel that personally I have seen cannabis used to aid the sick and terminal. But I know that we need to have better controls in place for safety in growing, processing and testing. But the crime here is that the sick and suffering patients who are suffering now without this medicine. They suffer because of ignorance created for financial gain of individuals and misguided beliefs propagated by the war on drugs.

[mtbooher]

I can't believe this even passed peer review with so many confounds. This is obvious propaganda and nothing more than a joke..

[Paulpots12]

Another study from New Zealand, land of the long white cloud of marijuana smoke.

NZ has the highest rate of marijuana use in the world.

If this study, and all the others from NZ were true, then NZ would be the drug zombie apocalypse.

Truth is the general mental and physical health of New Zealanders is no different to any other western nation or to the time before marijuana use became a popular national pass time.

The fact that tobacco use could not be separated from marijuana use is very telling. Many marijuana smokers mix tobacco with their marijuana.

Even more telling is the researchers dismissal of tobacco use as a factor.

Tobacco is known beyond any doubt to have negative health effects yet this so-called researcher is able to dismiss it. Clearly a case of bias in a field where bias has no place.

All in all just another piece of police state propaganda for the consumption of the masses.

[jimbo7776]

It would be interesting to compare the incidence of stroke in Marijuana smokers who don't use tobacco, MJ users who use the edible forms of cannabis and most importantly, comparable groups of people who do neither. Then, we'd have a useful study.

[Gpicciuto]

"However, all but one of the stroke patients who had marijuana in their urine also used tobacco..."

And there lies the truth about this study. How can you just put tobacco on the side of this study when it has shown to be deadly year after year causing strokes and a plethora of other diseases. The study and the headlines for this story are all wrong and misleading.

[brdwlsh]

Exactly. And beyond that, 7% is likely a low-ball number, so comparing the 7% to the percentage of stroke patients with pot in their system is bogus.

[malcolm-kyle]

Re-posted with corrections:

In this Auckland University study, all but one of the stroke patients who were cannabis users also used tobacco regularly.

The author (Dr. P. Alan Barber) openly admits that the study didn't account for tobacco use --how long and how much the young stroke patients had been smoking and how big a role that might have played in stroke risk.

According to the US National Stroke Association, "Smoking tobacco doubles the risk for stroke when compared to a non-smoker. It reduces the amount of oxygen in the blood, causing the heart to work harder and allowing blood clots to form more easily."

"Prohibitionists are scraping the bottom of the barrel by claiming that cannabis doubles the risk of stroke, when this result has already been linked to tobacco use. There is nothing scientific about this study and it should be discredited by all rational individuals."
--Norml president Julian Crawford

"Narcotics police are an enormous, corrupt international bureaucracy ... and now fund a coterie of researchers who provide them with 'scientific support' ... fanatics who distort the legitimate research of others.... The anti-marijuana campaign is a cancerous tissue of lies, undermining law enforcement, aggravating the drug problem, depriving the sick of needed help, and suckering well-intentioned conservatives and countless frightened parents." --William F. Buckley, commentary in The National Review, April 29, 1983, p. 495

[HmmmSaysDavidHume]

The willingness of Prohibitionists to distort and deceive the public shows how little regard they have for human rights, truth, the intelligence of the public, the citizens of this nation, or for that matter anything other than their own twisted morality.

The truth, per the American Heart Association's 2013 Report in the journal Circulation, is:

"Current smokers have a 2 to 4 times increased risk of stroke
compared with nonsmokers or those who have quit for >10
years."

This was cited from 2010 report by the Surgeon General. Citations are included in the American Heart Association study as well. Based on these statistics a case can be made that cannabis usage had no effect whatsoever on stroke risk. It is a valid question for scientific study.

But of course, Michele Leonheart and her ilk at the DEA do not fund any research on positive (or perhaps in this case, neutral) benefits of cannabis, despite the denials by former DEA administrator Robert Bonner in an LA Times letter.

Prohibitionists will stop at nothing, including lies on a massive scale. People of good conscience should look within themselves and ask if they should be supporting Prohibition when our government has lied to us all for forty years and continues to do so.

[malcolm-kyle]

In this Auckland University study, all but one of the stroke patients who were cannabis users also used tobacco regularly.

The author (Dr. P. Alan Barber) openly admits that the study didn't account for tobacco use —how long and how much the young stroke patients had been smoking and how big a role that might have played in stroke risk.

According to the US National Stroke Association, "Smoking tobacco doubles the risk for stroke when compared to a non-smoker. It reduces the amount of oxygen in the blood, causing the heart to work harder and allowing blood clots to form more easily."

"Prohibitionists are scraping the bottom of the barrel by claiming that cannabis doubles the risk of stroke, when this result has already been linked to tobacco use. There is nothing scientific about this study and it should be discredited by all rational individuals."
—Norml president Julian Crawford

"Narcotics police are an enormous, corrupt international bureaucracy ... and now fund a coterie of researchers who provide them with 'scientific support' ... fanatics who distort the legitimate research of others.... The anti-marijuana campaign is a cancerous tissue of lies, undermining law enforcement, aggravating the drug problem, depriving the sick of needed help, and suckering well-intentioned conservatives and countless frightened parents." - William F. Buckley, commentary in The National Review, April 29, 1983, p. 495

[santor420]

All but 1 person having a stroke used tobacco, which is known to cause strokes. Not able to find and other users of only marijuana having a stroke for the study. Sounds like a quack committing fraud to push his immoral ideas. Fake studies prove only that a fraud pretended to study something.

empirical data says study researcher Dr. P. Alan Barber is a fraud and a quack

[nursedeb49]

I do not believe smoking pot to be 100% safe, what I believe is that it is just as safe, if not safer than alcohol

[eczachly]

Funny how this was released the day before Hawaii is to vote on legalizing marijuana for recreational use. Coincidence? Released in Hawaii the day before a Hawaiian vote hummmmm....? Makes you think.