Inhalation study finds that the combination of tobacco and THC significantly increases amount of THC pulled out of cannabis.
It’s not until recently that the scientific community started to address combining tobacco and THC. About a decade ago, researchers began looking into whether combining the two would affect the distribution of cannabinoids, such as THC, CBD, and CBG.
A study was done using a small-scale smoking machine that mixed cannabis with various amounts of tobacco. The generated smoke was analyzed using high performance liquid chromatography, which is a gold standard in chemistry labs for quantitation. The amounts of THC, CBD, and CBG were determined for each cigarette.
Presence of Nicotine Increases THC Inhalation
The researchers found that tobacco increased the amount of THC inhaled per gram of cannabis. And, it increased it by as much as 45 percent. For a cannabis cigarette that was 100 percent herb, the amount of THC in the smoke was 32.70 ± 2.29 mg/g. Next researchers cut the cannabis with tobacco to make it 25 percent cannabis. Then the amount of THC increased to 58.90 ± 2.30 mg/g.
One thing to keep in mind is that scientists undertook these experiments in controlled laboratory conditions. Further, a machine generated the smoke. This study did not include humans. Therefore, we don’t know whether this increase will appear reliably in blood plasma.
Potential Pros and Cons of Tobacco and THC
The presence of tobacco in a cannabis cigarette increases the vaporization efficiency of THC. This means that one therapeutic avenue could be boosting the medicinal effects of THC. This includes pain killing, seizure prevention, and improving cachexia.
However, the principle of “the more the better” doesn’t necessarily apply in case of THC due to its biphasic effect: at lower doses it produces one effect and at higher doses the opposite effect. In an example of anxiety, at low concentrations THC is anxiety-relieving and at high doses anxiety-inducing.
Furthermore, it was also postulated that at lower levels, THC produces its effects via interactions with the CB1 receptor, whereas at higher concentrations, its preference is switched to TRPV1 receptors.
Neuroimaging studies were able to map the pain reducing effects of THC to a particular area of the brain called the anterior cingulate cortex. This area has a lot of CB1 receptors. It suggests that the pain relieving properties of THC are due to it activating CB1 receptors. This means that it favors the lower end of the THC concentration spectrum.
Therefore, it is tempting to speculate that increasing the vaporization efficiency of THC when mixing tobacco with cannabis would reduce the pain-reducing properties of THC. However, there is also evidence that THC produces analgesic effects via activation of TRPV1 ion channels, which appears to be favored over CB1 at higher THC concentrations.
In this case, mixing tobacco with cannabis would potentially deliver THC at this higher critical concentration. Importantly, scientists haven’t finished any pre-clinical or clinical studies yet. That means we can’t yet delineate exactly what, or where, these critical concentrations are. That means scientist must look for places where THC may switch preference from CB1 to TRPV; and figure out if this ties in with its pain-reliving potential.
Tobacco and Cannabis: Cumulative Harmful Effects?
Understanding the potential additive effects of tobacco and cannabis on health and toxic substance exposure is critical. Unfortunately, scientifically, we are not there yet. The fundamental question that still remains is whether it is the delivery system (smoking, vaping, ingesting) that causes interactions between tobacco and cannabis.
What If We Combine The Nicotine Patch With Cannabis?
In one interesting study, a randomized crossover trial tested the effects of applying a nicotine transdermal patch (containing 21 mg of nicotine) and smoking a cannabis cigarette containing 1.99% or 3.51% THC. This trial revealed that the transdermal nicotine patch produced no effect on plasma THC concentrations post-cannabis use. Looking into other potential cumulative effects of cannabis and tobacco, a cross-sectional study enrolled non-smokers of either cannabis or tobacco, exclusive cannabis smokers, exclusive tobacco smokers, and co-users.
The researchers measured oxidants produced from pulmonary alveolar macrophages, which is a measure of pathophysiological potential on development of emphysema. The results show that there was no additive effect of cannabis on oxidant production in tobacco users. Further, these tobacco users have higher oxidant levels irrespective of cannabis use. Cannabis-only smokers had similar oxidant levels to non-tobacco smokers.
So, small airway dysfunction appears to be attributable to tobacco alone, not cannabis.
This study suggests that adding tobacco to cannabis may expose individuals to health risks. These are risks that they would not encounter through only cannabis consumption. Therefore this appears to be a double-edge sword. It is up to each patient to decide if the benefits of combining tobacco and cannabis for certain aspects of treatment (such as pain relief) outweigh the damage to other physiologic systems (such as pulmonary system). What do you think?