Smoking cannabis may result in an acceleration of the biological aging process, according to a new study in the journal Drug and Alcohol Dependence. After analyzing the epigenomes of 154 people in the US, the researchers found that by the time they hit 30, regular stoners tend to display patterns of genetic activation that are beyond their years.
It is well established that the speed at which we age is not dependent solely upon Father Time, and that environmental factors play a key role in determining our rate of maturation. These external influences bring about changes in the expression of certain genes and therefore contribute to our epigenetic age.
In recent years, researchers have developed tools known as "epigenetic clocks", which look at patterns of DNA methylation in order to determine a person’s biological age. The study authors, therefore, decided to make use of these measures in order to investigate whether smoking weed brings about a discrepancy between an individual’s epigenome and their actual age.
Participants were initially recruited at the age of just 13, and were asked to report their annual level of cannabis use for a period of 17 years. At this point, the researchers used two separate epigenetic clocks to analyze blood samples from each individual.
Results showed a clear correlation between pot smoking and accelerated epigenetic aging, with heavier users displaying the greatest quickening of their biological clock. “There was a dose-effect relation observed such that just within the population of marijuana users, higher levels of lifetime use were linked to greater epigenetic age acceleration,” write the authors.
Importantly, these findings held firm even after the researchers adjusted for other factors such as cigarette smoking, prior health problems, socioeconomic background, personality traits, and lifetime history of depression and anxiety.
“These findings are all consistent with, though cannot conclusively establish, a causal role of marijuana use in epigenetic aging,” conclude the researchers.
Follow-up analyses indicated that the overall increase in epigenetic aging among pot users was correlated with changes within a particular hydrocarbon receptor repressor gene called AHRR. Similar alterations to this gene have previously been linked to cigarette smoking and exposure to air pollution.
Based on this observation, the researchers suggest that the epigenetic aging effects of cannabis are probably caused by the actual act of smoking rather than by the ingestion of THC or any other active component within weed. They also note that “links to epigenetic aging were dependent upon the recency of marijuana use, with more recent use strongly linked to age acceleration and with this effect fading for use in the more distant past.”
This final observation provides hope for those who want to slow down their personal ripening process, as it implies that the genetic impacts of getting baked may be “readily reversible when use ceases”.