By Janelle Lassalle
It's a universally acknowledged truth that any person who eats just a little too much turkey will fall asleep. But why is that the case? Is it the result of feeling satiated, or is something else going on?
The infamous culprit in this scenario is L-tryptophan, an essential amino acid found in turkey. This amino acid is the precursor for serotonin, a neurotransmitter that regulates our sense of mood and well-being. It also happens to be one of the few amino acids we can’t produce, meaning we have to get it through our diet. You can find L-tryptophan in a variety of foods such as cheese, bread, oats, milk and chocolate, which can explain why a holiday meal often results in a post-feast nap.
As cannabis continues to become normalized, its use—particularly during the holiday season—becomes inevitable. So how do the two interact with one another? Keep on reading to find out.
As mentioned earlier, tryptophan is an amino acid with a variety of functions within the body. The first is its use as a precursor for serotonin. This essentially means it’s one of the starting ingredients used by the body to produce 5-hydroxytryptamine (5-HT), aka the neurotransmitter serotonin. Serotonin, in turn, plays a role in regulating mood and is often implicated in conditions such as depression and addiction. It also has a role in governing cognitive function, regulating temperature, sleep and emotional behaviour.
Tryptophan is also involved in protein synthesis, a process in which the body uses amino acids to build essential proteins.
Cannabinoids & the serotonergic system
The serotonergic system that produces serotonin is found in the brain. This system is thought to be linked to the endocannabinoid system (ECS), a complex system of enzymes, ligands and receptors that helps the body maintain homeostasis (balance). The ECS is also involved in regulating mood, memory, pain, temperature, balance and sleep. It also plays a role in managing immune system functions within the body.
Plant-derived cannabinoids such as THC and CBD can interact with our ECS in a manner similar to our own naturally produced endocannabinoids. These cannabinoids “are involved in a variety of physiological and pathological conditions, including inflammation, immunomodulation, analgesia, and cancer.”
Cannabinoids in the ECS and serotonergic systems work together to help the body modulate stress responses. These responses, in turn, affect our mood and behaviours, particularly depression.
The bi-phasic properties of cannabis
One factor that plays a significant role in all of these interactions is cannabis’ bi-phasic nature. Bi-phasic means that cannabis can act in opposite ways depending on whether it’s present in a high or low concentration. This property is also thought to be the reason why certain people enjoy cannabis while others find it may be aggravating or anxiety-inducing.
So how is this relevant to tryptophan? Well, cannabis and tryptophan’s interactions are largely governed by this bi-phasic nature. This means that small doses of tryptophan produce the opposite effects as large doses.
Cannabis + tryptophan, explained
Research shows that the rate of serotonin being produced can be manipulated by the amount of tryptophan available.
Small amounts of cannabis (nanomolar) enhance the breakdown of tryptophan in the body. The breakdown of tryptophan results in lower available levels of tryptophan. Patients with inflammatory diseases tend to break down tryptophan more quickly.
Interestingly enough, researchers noted that in vitro studies on THC and CBD found that higher concentrations of these cannabinoids had the opposite effect. Larger doses (micromolar) of the two cannabinoids prevented the additional breakdown of tryptophan within the body. Even more interesting was the fact that CBD was found to be 2-4 times more potent in this respect than THC. This led researchers to conclude that, “...the non-psychotropic CBD is an attractive compound to improve mood disturbances and quality of life by its influence on tryptophan, and consequently serotonin metabolism, especially in diseases associated with inflammation.”
In short: larger doses of cannabinoids can help the body produce more serotonin by increasing the amount of precursor (tryptophan) available.
Tryptophan & disease
Remember how we mentioned earlier that tryptophan was also involved in protein synthesis?
The body essentially manipulates the amount of tryptophan available to suit its needs. A healthy body will generally benefit from increasing tryptophan’s availability, for instance. However regulating the amount of tryptophan plays an important role in how our body fights disease.
Reducing the amount of tryptophan available can help fight off extracellular invaders. When the amount of overall tryptophan is lowered, the degree to which protein synthesis is possible also becomes reduced. This effect can reduce the growth of extracellular organisms like viruses, bacteria and proliferating tumor cells. Depleting the amount of tryptophan available can also suppress T-cell responsiveness “which may be important in tolerance induction.” Tolerance induction refers to the process in which the immune system stops responding to substances that generally elicit a response. It’s a self-defense mechanism that can benefit people with compromised immune systems such as AIDS patients.
Tryptophan is an amino acid found in foods like cheese, milk and turkey. It’s the precursor molecule to the neurotransmitter serotonin which governs mood and behavior. The serotonergic system that produces serotonin is also linked to the endocannabinoid system (ECS) as the two work together to regulate mood.
Cannabinoids like CBD and THC exhibit bi-phasic properties with respect to tryptophan. Small amounts of THC or CBD result in an accelerated breakdown of tryptophan. This may benefit patients with compromised immune systems as it limits the growth of extracellular organisms and proliferating tumor cells by restricting protein synthesis.
Larger amounts of cannabinoids, however, suppress the body’s breakdown of tryptophan, increasing the overall amounts available. Cannabinoids’ ability to increase the amount of tryptophan in the body may help the body better modulate serotonin signaling.
Consuming large amounts of cannabis at Thanksgiving, then, seems like it would result in an overall sense of improved well-being for most. Patients suffering from certain conditions such as human immunodeficiency virus (HIV) infection or autoimmune syndromes want to consider imbing less than their healthy counterparts as reducing tryptophan can limit the growth of proliferating tumor cells.