Researchers Find the 1st Possible Negative Side Effect of Marijuana Use in Adults
Brain blood flow in those with cannabis use disorder was found to be significantly restricted.
The stigma against marijuana in the US has been eroding for decades. But over the last ten years, use has skyrocketed. Since 2002, the number of Americans using the drug has almost doubled, according to a recent survey. In 2001, 4.1% said they had smoked marijuana within the past year. By 2014, 9.5% had done so. The number of patients using it to control the symptoms of an illness or disorder has risen substantially as well. Since it has been found far less dangerous that alcohol and other intoxicants, cannabis is quickly becoming the drug of choice for many Americans. New laws have allowed for medical marijuana in over half the states and recreational marijuana in about a half dozen.
Cannabis is also the most commonly used illicit drug in the world, according to the WHO. While opponents to liberalization often talk about it as a gateway drug, there is little evidence of this. In fact, scant data exists alleging that marijuana causes any damage whatsoever, if used in moderation, once the brain has stopped developing. But for chronic users, a new study imposes a harsh warning.
Researchers at Amen Clinics Inc. of California have found evidence that chronic use may increase the risk of Alzheimer’s. This is because it restricts blood flow to the regions of the brain where the condition takes root. Co-author Dr. Elisabeth Jorandby and colleagues recruited participants with marijuana use disorder. Around nine percent of users get addicted to cannabis. That’s a relatively low number.
Cannabis or marijuana use disorder is defined as using the drug chronically, even when it is clearly causing significant cognitive impairment. The symptoms may be mild, moderate, or severe, depending on the particular case. Chronic use is considered daily or near daily use. Those who habitually consume are more susceptible to psychiatric disorders.
Medical marijuana is available in 28 states in the US today. Seven states now allow the recreational kind, and many more cities across the nation have decriminalized pot.
In this study, published in the Journal of Alzheimer’s Disease, 982 current or former chronic users and 92 healthy controls underwent brain scans to evaluate blood flow there. Those diagnosed with cannabis use disorder showed a significant reduction in brain blood flow in almost every region. The hippocampus, which is where Alzheimer’s originates, saw the largest reduction. This is the area responsible for learning and memory.
Few previous studies have evaluated blood flow inside the brain as an effect of chronic marijuana use, researcher’s said. This was measured using single photon emission computed tomography (SPECT). Participants had their brains scanned while performing a task and while at rest. Reduced brain blood flow would cause less oxygen to travel to neurons, which could lead to tissue damage.
Blood flow was especially restricted in the right hippocampus. Researchers believe marijuana may affect memory formation due to this effect. The study suggests consistent marijuana use causes damage to the brain. Possible effects include memory formation disruption. Other studies have suggested that restricted blood flow to the hippocampus can increase the risk of Alzheimer’s.
More research will have to be conducted to corroborate this claim. But it’s reasonable that someone who only lights up occasionally won’t have such an issue. This study conflicts with a 2014 preclinical trial, also published in the Journal of Alzheimer’s Disease. There, tiny doses of marijuana’s active ingredient, delta 9-tetrahydrocannabinol (THC) had neuroprotective qualities. It helped ward off Alzheimer’s by destroying beta amyloid proteins which are what cause the disease. So in the end, it may be an issue of dosage. A little is okay, but too much is damaging. But only more studies can tell us for sure.
To learn how marijuana affects memory in the short-term, click here:
What can 3D printing do for medicine? The "sky is the limit," says Northwell Health researcher Dr. Todd Goldstein.
- Medical professionals are currently using 3D printers to create prosthetics and patient-specific organ models that doctors can use to prepare for surgery.
- Eventually, scientists hope to print patient-specific organs that can be transplanted safely into the human body.
- Northwell Health, New York State's largest health care provider, is pioneering 3D printing in medicine in three key ways.
A recent study gives new meaning to the saying "fake it 'til you make it."
- The study involves four experiments that measured individuals' socioeconomic status, overconfidence and actual performance.
- Results consistently showed that high-class people tend to overestimate their abilities.
- However, this overconfidence was misinterpreted as genuine competence in one study, suggesting overestimating your abilities can have social advantages.
Is this proof of a dramatic shift?
- Map details dramatic shift from CNN to Fox News over 10-year period
- Does it show the triumph of "fake news" — or, rather, its defeat?
- A closer look at the map's legend allows for more complex analyses
Dramatic and misleading
Image: Reddit / SICResearch
The situation today: CNN pushed back to the edges of the country.
Over the course of no more than a decade, America has radically switched favorites when it comes to cable news networks. As this sequence of maps showing TMAs (Television Market Areas) suggests, CNN is out, Fox News is in.
The maps are certainly dramatic, but also a bit misleading. They nevertheless provide some insight into the state of journalism and the public's attitudes toward the press in the US.
Let's zoom in:
- It's 2008, on the eve of the Obama Era. CNN (blue) dominates the cable news landscape across America. Fox News (red) is an upstart (°1996) with a few regional bastions in the South.
- By 2010, Fox News has broken out of its southern heartland, colonizing markets in the Midwest and the Northwest — and even northern Maine and southern Alaska.
- Two years later, Fox News has lost those two outliers, but has filled up in the middle: it now boasts two large, contiguous blocks in the southeast and northwest, almost touching.
- In 2014, Fox News seems past its prime. The northwestern block has shrunk, the southeastern one has fragmented.
- Energised by Trump's 2016 presidential campaign, Fox News is back with a vengeance. Not only have Maine and Alaska gone from entirely blue to entirely red, so has most of the rest of the U.S. Fox News has plugged the Nebraska Gap: it's no longer possible to walk from coast to coast across CNN territory.
- By 2018, the fortunes from a decade earlier have almost reversed. Fox News rules the roost. CNN clings on to the Pacific Coast, New Mexico, Minnesota and parts of the Northeast — plus a smattering of metropolitan areas in the South and Midwest.
Image source: Reddit / SICResearch
This sequence of maps, showing America turning from blue to red, elicited strong reactions on the Reddit forum where it was published last week. For some, the takeover by Fox News illustrates the demise of all that's good and fair about news journalism. Among the comments?
- "The end is near."
- "The idiocracy grows."
- "(It's) like a spreading disease."
- "One of the more frightening maps I've seen."
- "LOL that's what happens when you're fake news!"
- "CNN went down the toilet on quality."
- "A Minecraft YouTuber could beat CNN's numbers."
- "CNN has become more like a high-school production of a news show."
Not a few find fault with both channels, even if not always to the same degree:
- "That anybody considers either of those networks good news sources is troubling."
- "Both leave you understanding less rather than more."
- "This is what happens when you spout bullsh-- for two years straight. People find an alternative — even if it's just different bullsh--."
- "CNN is sh-- but it's nowhere close to the outright bullsh-- and baseless propaganda Fox News spews."
"Old people learning to Google"
Image: Google Trends
CNN vs. Fox News search terms (200!-2018)
But what do the maps actually show? Created by SICResearch, they do show a huge evolution, but not of both cable news networks' audience size (i.e. Nielsen ratings). The dramatic shift is one in Google search trends. In other words, it shows how often people type in "CNN" or "Fox News" when surfing the web. And that does not necessarily reflect the relative popularity of both networks. As some commenters suggest:
- "I can't remember the last time that I've searched for a news channel on Google. Is it really that difficult for people to type 'cnn.com'?"
- "More than anything else, these maps show smart phone proliferation (among older people) more than anything else."
- "This is a map of how old people and rural areas have learned to use Google in the last decade."
- "This is basically a map of people who don't understand how the internet works, and it's no surprise that it leans conservative."
A visual image as strong as this map sequence looks designed to elicit a vehement response — and its lack of context offers viewers little new information to challenge their preconceptions. Like the news itself, cartography pretends to be objective, but always has an agenda of its own, even if just by the selection of its topics.
The trick is not to despair of maps (or news) but to get a good sense of the parameters that are in play. And, as is often the case (with both maps and news), what's left out is at least as significant as what's actually shown.
One important point: while Fox News is the sole major purveyor of news and opinion with a conservative/right-wing slant, CNN has more competition in the center/left part of the spectrum, notably from MSNBC.
Another: the average age of cable news viewers — whether they watch CNN or Fox News — is in the mid-60s. As a result of a shift in generational habits, TV viewing is down across the board. Younger people are more comfortable with a "cafeteria" approach to their news menu, selecting alternative and online sources for their information.
It should also be noted, however, that Fox News, according to Harvard's Nieman Lab, dominates Facebook when it comes to engagement among news outlets.
CNN, Fox and MSNBC
Image: Google Trends
CNN vs. Fox (without the 'News'; may include searches for actual foxes). See MSNBC (in yellow) for comparison
For the record, here are the Nielsen ratings for average daily viewer total for the three main cable news networks, for 2018 (compared to 2017):
- Fox News: 1,425,000 (-5%)
- MSNBC: 994,000 (+12%)
- CNN: 706,000 (-9%)
And according to this recent overview, the top 50 of the most popular websites in the U.S. includes cnn.com in 28th place, and foxnews.com in... 27th place.The top 5, in descending order, consists of google.com, youtube.com, facebook.com, amazon.com and yahoo.com — the latter being the highest-placed website in the News and Media category.
If you thought your mother was pushy in her pursuit of grandchildren, wait until you learn about bonobo mothers.
- Mother bonobos have been observed to help their sons find and copulate with mates.
- The mothers accomplish this by leading sons to mates, interfering with other males trying to copulate with females, and helping sons rise in the social hierarchy of the group.
- Why do mother bonobos do this? The "grandmother hypothesis" might hold part of the answer.
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