What happens when you smoke for two
The study worked with 5628 pregnant women in Australia, New Zealand, Ireland, and the United Kingdom who were also part of a separate study investigating the relationship between marijuana use and pregnancy complications. These women had their demographic information, lifestyle characteristics, and medical history collected by a midwife.
All participants were asked if they ever smoked marijuana and, if so, if had they smoked it at any point during their pregnancy. Those who did smoke were further asked how many times a week they partook. Similar questions were asked for alcohol and tobacco usage. The midwives also recorded socio-economic data, noted if the test subject had used other illicit drugs during their pregnancy, and administered tests checking for depression and anxiety. After the test subjects gave birth, the midwives recorded infants' size and weight.
The babies born to women who smoked past the 15-week point in their pregnancies had lower birth weights, head size, body length, and lower gestational age. The reductions were comparable to the known effects of an expecting mother smoking nine cigarettes a day. These effects were more dramatic for children born to mothers who smoked more frequently. The risk of infant death and the rate of severe infant morbidity increased with the frequency of smoking as well.
Women who stopped smoking before the 15th week gave birth to babies with similar measurements to those born to women who did not smoke.
The evidence behind these findings remained even after factoring for tobacco and alcohol usage. While those lower on the socio-economic scale were more likely to continue smoking during pregnancy than others, their lower social standing was found to have no direct relation to birth outcomes.
The study was not without limitations. The number of women who reported continuing to smoke throughout their pregnancy was comparatively low, though not so small as to reduce the validity of the findings.
The researchers only looked at the number of times a person smoked and not at the potency of the marijuana or how it was consumed. They also looked at the effects of taking other illicit substances, but the number of women taking them was low enough to make serious investigation impossible during this study.
Perhaps most importantly, the study did not investigate what mechanism is at work. It could be simple carbon monoxide production by the act of smoking cutting down on oxygen that is getting to the fetus, as with tobacco smoking. Or it could be that the chemicals in marijuana were affecting the fetus. This is an area where further research is needed.
So, what does this mean for me?
The first take away here is that you shouldn't smoke weed while pregnant. The second is that it might not be too late to stop.
Previous studies have suggested that a lower gestational age at birth is associated with lower literacy later in life and that children in families with lower social standing start behind their wealthier peers in literacy tests. The finding here that lower-income women are more likely to smoke during pregnancy suggests that their children may be subject to particular difficulties.
The study is yet another one suggesting that marijuana isn't as harmless as many people suppose. The drug is known to cause memory trouble, anxiety, and increase the risk of psychotic symptoms. Previous studies similar to this one already hinted at the effects of smoking on the newly born. This one didn't break new ground so much as remove hidden variables in previous experiments on the same subject.
Despite this, up to a third of women think marijuana can't harm a gestating fetus, and the popular conception of the drug has yet to incorporate notions of its various adverse side effects.
Perhaps the take away for those who are not or cannot become pregnant is that marijuana isn't completely harmless and should be interacted with as such.
A new study suggests that using marijuana in your teenage years may prime your brain to respond positively to your first experience with cocaine. The findings offer molecular insight into the question of whether marijuana is a gateway drug. After all, studies have repeatedly shown that having a good first experience with a drug makes you more likely to use it again, and therefore potentially become addicted.
The study is published in the journal PNAS.
"We know from human epidemiological studies that individuals who abuse cocaine have a history of early cannabis use, and that a person's initial response to a drug can have a large impact on whether they continue to use it. But many questions remain on how early cannabis exposure affects the brain," epidemiologist Denise Kandel, PhD, a professor of Sociomedical Sciences in Psychiatry at Columbia's Vagelos College of Physicians and Surgeons and co-senior author of the new study, told Science Daily.
In the study, researchers gave a synthetic psychoactive cannabinoid called WIN 55,212-2 (WIN) to adolescent and adult rats. Then, both groups of rats were given cocaine, and the researchers monitored how the animals responded.
Fig 1. Cross-sensitization between WIN and cocaine in adolescent rats is associated with histone hyperacetylation in the PFC.
Scherma et al.
The results showed that young rats who had been exposed to WIN were more sensitive to the effects of cocaine. This early exposure "reprograms the initial behavioral, molecular, and epigenetic response to cocaine" in young rats. These changes were not observed in adult rats.
Past research has shown that young rats that have been exposed to cannabinoids become "cross-sensitized" to cocaine, and that cross-sensitization can alter the extent to which rats crave cocaine and experience withdrawal symptoms.
The new study took a close look at how cannabinoids prime bodily systems for cocaine.
Changes in the prefrontal cortex
One such system is the endocannabinoid system, which is impaired by the use of cannabis or cannabinoids. Studies have linked impaired endocannabinoid signaling with increased stress responsivity, negative emotional states, and drug craving.
"The endocannabinoid system has a modulatory role in brain reward and cognitive processes," the researchers wrote. "It has been hypothesized that repeated interference with endocannabinoid signaling (e.g., through abuse of cannabis or synthetic cannabinoids) can remodel the adolescent brain and make it respond differently to more addictive substances, such as cocaine. In the present study, we demonstrate that a history of synthetic cannabinoid exposure in adolescent animals results in distinct molecular and epigenetic changes following initial exposure to cocaine."
In addition to affecting the endocannabinoid system and (potentially) the glutamatergic system, the study found that early cannabinoid use seems to cause epigenetic changes in the prefrontal cortex. This area of the brain controls executive functions like long-term planning and self-control.
"Our findings suggest that exposure to psychoactive cannabinoids during adolescence primes the animals' prefrontal cortex, so that it responds differently to cocaine compared to animals who had been given cocaine without having previously experienced cannabis," study co-senior author Philippe Melas told Science Daily.
One consequence of priming the prefrontal cortex in this way seems to be that cocaine becomes more enjoyable.
"This study suggests that teenagers who use cannabis may have a favorable initial reaction to cocaine, which will increase their likelihood of engaging in its repeated use so that they eventually become addicted, especially if they carry additional environmental or genetic vulnerabilities," Kandel told Science Daily.
Limitations
The researchers noted several limitations in their study, including:
- The use of experimenter-administered drug regimens instead of self-administration procedures
- The use of synthetic cannabinoids instead of Δ9-THC
- The assessment of neurobiological changes in bulk tissue instead of cell type-specific analyses
- The lack of in vivo causality experiments rendering the molecular data correlational in nature
They also noted that someone won't necessarily develop an addiction if they happen to have a good first experience with a drug. Still, they suggested that research like this can help to develop better treatments for substance abuse disorders.
"These and other experiments are key to understanding the molecular changes to the brain that occur during drug use," said Dr. Eric Kandel, who is also University Professor and Kavli Professor of Brain Science at Columbia. "This knowledge will be crucial for developing effective treatments that curb addiction by targeting the disease's underlying mechanisms."
Surgeons are not squeamish people, so when one of them says, "This is an evil that I haven't faced before" it gets your attention. The doctor is Hassan Nemeh, surgical director of thoracic organ transplant at Detroit's Henry Ford Hospital. The evil is the stunning wreck that vaping made of a 17-year-old double-lung transplant patient's lungs.
"What I saw in his lungs was nothing that I've ever seen before, and I've been doing lung transplants for 20 years," says Nemeh. That vaping, particularly of cannabis products using THC oils, has become a major public health crisis is indisputable: Since March, vaping-related illness has landed over 2,000 individuals in hospitals nationwide, and at least 39 of those people have died.
The patient in Detroit
mage source: James R. Martin/Shutterstock
Not much information regarding the individual described by Nemeh has been released, since he's a minor. What we do know is that his family has described him as an otherwise-healthy young athlete.
The teen was admitted to the first of three hospitals, St. John Hospital, September 5 with what seemed to be pneumonia. His breathing, however, became increasingly difficult until he was put on a ventilator September 12. He was soon transferred to Children's Hospital of Michigan to be connected to an extracorporeal membrane oxygenation device (ECMO) in order to maintain heart and lung functioning. Still failing, he was transferred to Henry Ford for a six-hour, double-lung transplant on October 15, without which, doctors say, he would certainly have died.
"There was an enormous amount of inflammation and scarring in addition to multiple spots of dead tissue. And the lung itself was so firm and scarred, literally we had to deliver it out of the chest," recalls Nemeh.
THC and vitamin E acetate
Vitamin E acetete
Image source: ibreakstock/Shutterstock
When the medical community first became aware of the pulmonary problems, it was unclear what aspect of vaping was causing them. Likewise, it was unclear whether it was tobacco or THC vaping that was causing the problems, or both.
Scientists from the CDC tested for the presence of potential culprits in victims' lung fluid, looking for plant oils, petroleum distillates including mineral oils, or any other suspicious contaminants common to the individuals' cases.
What they found — though there could still be additional substances involved — was vitamin E acetate, or tocopheryl acetate. Collecting 29 lung-fluid samples from 29 people who had been sickened or who had died of lung issues, all 29 contained vitamin E acetate. The CDC's Dr. Jim Pirkle says that's "pretty much unheard of," and constitutes a "very strong signal" that vitamin E acetate is at the very least part of the reason for vapers' pulmonary damage.
CDC officials have concluded that most of the patients had vaped cannabis-based products. This is supported by state testing — New York's reports finding "very high levels of vitamin E acetate in nearly all" of the samples from cannabis vapers they tested. While the federal FDA remains cautious about putting all the blame on vitamin E acetate, they, too, have found it to be prevalent in afflicted vapers' lungs. Medical authorities are continuing to test for other possible factors in the frequency of pulmonary illnesses among vapers.
Legitimately manufactured and sold cannabis-based vaping products don't necessarily contain vitamin E acetate. However, the sticky, honey-like substance is commonly used as a thickener in black-market THC products. Unlike THC itself, vitamin E acetate lingers in users' lungs. These unregulated, illicit cannabis-based vaping products, say experts, have indeed been linked to most of the cases medical professionals are seeing.
"This is a preventable tragedy," says Nemeh. While vaping is presumed by many to be safer than smoking, this current public health crisis makes clear that caution is advised, especially when buying vaping products off the street.
