Take a deep breath!
In 2012, a study at the University of California, San Francisco (UCSF) calculated that even smoking an individual joint each day for 20 years may be benign, though most participants only smoked two or three joints each month. “I was surprised we didn’t see effects [of marijuana use],” said UCSF epidemiologist Mark Pletcher, who led the study.
One assessment of varied epidemiological studies points to small sample size and poor study design as reasons for scientists’inability to nail down a link between cannabis and cancer risk. But some suspect that this type of link doesn’t exist, and that marijuana could even have cancer-preventive effects. A 2008 study, for example, suggested that smoking marijuana may reduce the danger of tobacco-associated lung cancer, calculating that folks who smoke both marijuana and tobacco have a diminished danger of cancer than those who smoke only tobacco (though still a greater risk than non-smokers).
But even Pletcher isn’t sanguine about marijuana’s effects on the lungs, and suspects that there could still be long-term lung damage which can be hard to detect. “We really can’t reassure ourselves about heavy use,” he explained.
Your brain on drugs
There’s some evidence to claim that stoned subjects exhibit increased risk-taking and impaired decision-making, and score worse on memory tasks-and residual impairments have been detected days or even weeks after use. Some studies also link years of regular marijuana use to deficits in memory, learning, and concentration. A recently available and widely discussed report on the IQs of New Zealanders followed since birth discovered that cannabis users who’d started their habit in adolescence had lower IQs than non-users.
In this study, led by researchers at Duke University, “you may clearly see as a consequence of cannabis use, IQ falls,” said Derik Hermann, a clinical neuroscientist at the Central Institute of Mental Health in Germany who was not active in the research.
However not 4 months later, a re-analysis and computer simulation at the Ragnar Frisch Center for Economic Research in Oslo countered the Duke findings. When is the best time to eat CBD gummies? Ole Rogeberg contended that socioeconomic factors, not marijuana use, contributed to the low IQs observed in cannabis users.
Rogeberg’s conclusion counters a sizeable literature, however, which supports a link between pot use and neurophysiological decline. Studies in both humans and animals suggest that folks who acquiring a marijuana habit in adolescence face long-term negative impacts on brain function, with some users finding it difficult to concentrate and learn new tasks.
Notably, most studies on the subject claim that while there may be negative consequences of smoking as a young adult, users who begin in adulthood are usually unaffected. This may be as a result of endocannabinoid-directed reorganization of the mind during puberty, Hermann explained. The intake of cannabinoids that accompany pot use could cause irreversible “misleading of the neural growth,” he said.
Along with the results for intelligence, many studies claim that smoking marijuana raises the danger of schizophrenia, and could have similar effects on the brain. Hermann’s group used MRI to detect cannabis-associated neuron damage in the pre-frontal cortex and found that it was much like brain changes observed in schizophrenia patients. Other studies further claim that weed-smoking schizophrenics have greater disease-associated brain changes and perform worse on cognitive tests than their non-smoking counterparts.
But much of this research can’t distinguish between brain changes caused by marijuana use and symptoms related to the disease. It’s possible that cannabis-smoking schizophrenics “could have unpleasant symptoms [that precede full-blown schizophrenia] and are self-medicating” with the psychotropic drug, said Roland Lamarine, a professor of community health at California State University, Chico. “We haven’t seen a growth in schizophrenics, despite a lot more marijuana use.”
Actually, other research suggests that cannabis-using schizophrenics score better on cognitive tests than non-using schizophrenics. Such conflicting reports might be as a result of varying concentrations-and varying effects-of cannabinoids in marijuana. Along with tetrahydrocannabinol (THC), a neurotoxic cannabinoid that’s in charge of marijuana’s mind-altering properties, the drug also contains many different non-psychoactive cannabinoids, including cannabidiol (CBD), which could force away neuron damage. Hermann discovered that the quantity of the hippocampus-a brain area very important to memory processing-is slightly smaller in cannabis users than in non-users, but more CBD-rich marijuana countered this effect.
A lethal cocktail?
While data supporting the harmful ramifications of marijuana alone are weak, some researchers are more worried about the drug along with other substances, such as for instance tobacco, alcohol, or cocaine. Some studies suggest, for example, that marijuana may increase cravings for other drugs, resulting in its infamous tag as a “gateway drug.” A study published earlier this month supported this theory when it discovered that, at the least in rats, THC exposure increases tobacco’s addictive effects. Furthermore, marijuana may not mix well with prescription drugs, as cannabis causes the liver to metabolize drugs more slowly, raising the danger of drug toxicity.