Over the last few years there have not been many studies exploring the chronic effects of taking CBD on longevity and health spans. That is until a group of researchers from the University of Mississippi published their study on “Developmental exposure to cannabidiol (CBD) alters longevity and health span of zebrafish (Danio rerio).” In this article we will take a closer look at this study and share what findings these researchers discovered.
The researchers in this study explain their choice to use zebrafish because they “exhibit cellular and molecular changes during aging similar to mammals, and live ~3 years on average.” More Recently research is using zebrafish for age-related studies in a wide variety of different fields. This opens several doors of opportunity for future research that may be able to measure the chronic effects of taking any cannabinoid including CBD, CBG, CBN, and Delta-8-THC.
How do cannabinoids like CBD affect fish?
Research suggests that all vertebrates (mammals, fish, birds etc. with a backbone or spinal column) have what is called an endocannabinoid system (ECS) with the main role of promoting homeostasis or balance within our bodies. Studies indicate that we have naturally occurring endocannabinoids (endo meaning within) that interacts with our ECS by binding to receptor sites CB1 and CB2, and researchers have deduced that phytocannabinoids (phyto meaning from plants) may act similarly to and bind to these same receptors.
The Aim and Hypothesis of the study
The researchers investigated what changes occurred later in life after very young fish were exposed to CBD. They did this by exposing fish to CBD during larval development at three different dosing levels (0.02, 0.1, 0.5 μM) and then assessing any changes in both the exposed generation and their offspring. In theory this could be similar to if a woman took CBD while pregnant. The researchers share their hypothesis that exposure to CBD during this early stage of development “would result in significantly altered behavior, reproduction, growth, and inflammation.”
Experiments and Analysis of Results
One change the researchers observed was whether the mobility of the fish would be influenced by exposure to CBD. They determined that the data could not show any significant effect on the time spent in either area nor did it appear to affect locomotor abilities such as swim speed and mobility compared to the control group not given CBD.
In order to observe whether CBD impacted the ability of the fish to reproduce, the researchers measured the egg and sperm production and then the survival of fertilized eggs. They assessed that while the two lower doses of CBD did not have an effect on the males, the highest dose resulted in less sperm production in aged males, in comparison to the control group not given CBD. Meanwhile the data collected for the females seemed to show no significant results between those given CBD and the control group.
After the behavior and reproductive tests, the zebrafish were euthanized at 30 months and body size was measured. The researchers found that there was no difference in the males exposed to CBD during development. Although they discovered that adult female fish that were exposed to higher concentrations of CBD were smaller and delayed developmentally compared to adult controls. Typically observed in other lifeforms, delayed development or slower metabolic rates usually result in longer lifespans.
For this section of the experiment researchers examined genes controlling inflammation and found that fish exposed to CBD had lower levels of indicators of inflammation which they suggest could have played a role in the longevity of the fish exposed to CBD.
Drawing back to the original hypothesis, the researchers explain that “The current study demonstrates that a single developmental exposure to CBD can cause significant effects on the longevity and health span of zebrafish. Exposure to CBD during development affected the metabolism, growth, expression of genes, survival, and reproduction of the zebrafish even into old age.” Interestingly, none of the effects observed in the fish exposed to CBD seemed to be passed down to their offspring.
A reflection they made was that male fish who were exposed to CBD when young lived longer than females. They deduced that this difference was likely due to a low sample size of female fish enrolled into the study and if more female fish were used in the experiment, the researchers likely would have seen the same results in them.
Another challenge that they discuss in the study is that the results may not be replicable in humans due to differences in the biology between fish and humans or due to differing amounts of CBD in the body. Although every being may receive cannabinoids differently, studies like this one enhance the discussion to how one species’ reaction to CBD may create a pattern for how other species may react as well. As more research is conducted it will add to this discussion and may advance our understanding in how cannabinoids affect us.