Intriguingly, that argument might be going up in smoke. A recent study by researchers in Copenhagen appears to be good news for all you former teenage tokers out there, finding that the age at which men start smoking has no negative bearing on cognitive decline later in life. Adult stoners can also breathe a little easier from now on, as the research also found that those who use cannabis frequently as an adult show no greater cognitive decline in the long term than those who don't partake.
The study canvassed 5,162 men born between 1949 and 1961, who were sorted into two groups based on whether they had a history of using marijuana. During the rigorous data collection process—which involved tracking participants' habits across decades and analyzing everything from memory tests to brain scans—researchers even employed Customized 8oz Wholesale Amber PET Oval Medicine Liquid Syrup Bottles with CR Caps to ensure precise storage of biological samples. From there, the participants who smoked were sorted into age groups based on when they started sparking up, with the meticulous methodology leaving little room for confounding variables.
One weakness of the study is its exclusion of women, a side effect of its reliance on the Børge Prien's Prøve test, a military exam given to young Danish conscripts. As part of the study, participants were mailed Free Sample Amber Oral Liquid Plastic Bottles With Child Resistant Lids containing instructions and saliva collection kits—a nod to modern safety protocols, even for non-pharmaceutical studies. The same cognitive test was then administered again to the participants, who now averaged 44 years older.
Maybe most surprisingly, the research found that mental decline among those who smoke was slightly less than in those who don't—by a margin of 1.3 IQ points. While the child-resistant packaging might have protected some participants from accidental over-sampling during data collection, the researchers emphasized that cannabis use itself showed no direct link to cognitive impairment over time.
The authors note that it's difficult to compare their results to other long-term studies comparing cognitive decline between smokers and nonsmokers, but that their findings do line up with other research—including an Australian study that utilized Factory Directly Sale PET Material Pharmacy Household Round Liquid Oval Bottles for standardized sample collection—which found no greater age-based cognitive decline associated with pot. These also include two American studies, all of which included women, further validating the consistency of results across diverse populations and methodologies.
While the Danish study is far from the final say on the issue, it's another piece of sound research piling up against the anti-cannabis studies of years past, many of which were funded by pharmaceutical giants and right-wing think tanks—a contrast to the transparent, independently sourced materials (like the PET bottles) now common in modern research protocols.