Hormones are messengers of the body.
What is understood as a hormon?
Hormones are messengers of the body. They conduct information from one area of the body to the other and help to process certain perceptions, influences and initiate processes. There are many different hormones, each with a different function. The best known are the so-called sex hormones testosterone and estrogen. Just because the sex hormones are often assigned to one sex does not mean that the other sex does not produce them. Though testosterone is produced in women and estrogen in men. Both hormones have different functions and are found in different concentrations in every human being. Estrogens are also referred to as the female sex hormone because, for example, they are fundamentally involved in controlling the female menstrual cycle and pregnancy. Estrogens also have an effect on metabolism and bone formation. And are therefore just as necessary for the male organism. Testosterone helps in muscle building and also affects bones, skin and organs. In addition to these hormones, there are many more, hormones for reproduction (e.g. luteinizing hormone), sex hormones (e.g. follicle stimulating hormone (FSH)) and thyroid hormones. All of these influence important processes in the body in terms of their concentrations, their receptor binding and their activity. They also play a major role in diseases.
What role have cannabinoids?
In some diseases, there can be an imbalance in the body’s endocannabinoid system, where administration of cannabinoids has medicinal benefits. To what extent various hormone receptors and hormone processes are related to the endocannabinoid system and to what extent the administration of medicinal cannabis can lead to an improvement in symptoms has been investigated in various animal studies and isolated field studies. Since the sex hormones in particular play an important role, the influence of cannabinoids on testosterone, estrogen, etc. has been of the biggest interest.
Cannabinoids for breast cancer treatment
Researchers led by Luka Dobovišek at the Institute of Oncology in Ljubljana, Slovenia, researched the effects of cannabinoids on hormone receptors and breast cancer. In the review that was published in 2020, the effects of previous studies were summarized and critically examined. Estrogen receptors predict response to endocrine therapy in breast cancer patients. Therefore, the functionality and activity of these hormone receptors are particularly important in the treatment of breast cancer. In the studies, researchers found that THC has an inhibitory effect on the proliferation of estrogen receptor-positive breast cancer cells. So, simplified, could affect the production of breast cancer cells. The connection only suggests an interaction between estrogen and THC, further research is needed to find out the actual effect of treatment with medical cannabis on tumor growth etc. in breast cancer patients.
Interaction of cannabinoids and sex hormones
In an animal study from 1979, Harris Rosenkrantz and colleagues looked at hormone changes by cannabinoid administration. The study, conducted at the EG&G Mason Research Institute in Worcester, Massachusetts, followed rats dosed with 2, 10, or 50 mg/kg of Δ 9 -THC for 14-180 days. Other rats were exposed to the smoke of marijuana at Δ 9 -THC doses of 2 or 4 mg/kg for 14 days. In addition, male and female rhesus monkeys received oral cannabidiol doses of 30, 100 and 300 mg/kg for 90 days. The smoke, as well as oral THC, resulted in a 20-30% drop in testosterone levels and a 17-29% drop in thyroid hormone (Triiodothyronin). In addition, an increase in sex hormones (FSH) was found in male and female monkeys as well as in female rats. The effects of changes in sex and thyroid hormones on humans needs to be further researched. However, an interaction between the hormones and cannabinoids has been proven at different ways of administration and doses.
Gender differences in the interaction of cannabinoids and hormones
When examining the interaction between sex hormones and cannabinoids, gender must also be taken into account. Charlotte Farquhar et al. examined the gender-specific differences in the effects of Δ9-tetrahydrocannabinol (THC) in an animal study in 2019. Specifically, the effect of gender and sex hormones on cannabinoid receptors in the brain. Female rats injected with THC showed increased receptor activation in the hippocampus compared to male rats. The hippocampus is the working memory of the brain and is related to short- and long-term memory. An interaction between cannabinoids and sex hormones has been determined in female animals in a sex-specific manner. This finding should be taken into account when prescribing medicinal cannabis, particularly for the treatment of conditions involving hormones. Upon repeated treatment with THC, desensitization of the cannabinoid receptors in all areas of the brain developed in the rats was found in the study from Farquhar. This shows an increased tolerance for THC from regular administration. The finding was stronger in female animals than in males. Therefore one can assume that women tend to become more tolerant and dependent than men once they start using cannabis. More research is needed in this area to understand the impact more concretely and specifically.
The interaction of cannabinoids and hormones has been examined in various studies. Sex and thyroid hormones were of particular interest. Existing research suggests interactions that can go in different directions and mostly show the existence of an interaction first, but not yet concrete to what extent the interaction affects the larger system and could be particularly useful in the treatment of diseases. There are already research approaches to the treatment of breast cancer that suggest a potential tumor cell-reducing effect of THC. However, this still needs to be researched further.
With the existent evidence linking hormone levels and various cannabinoids, more research is needed into the potential medical benefits of this knowledge. Next questions for further research could be, to what extent, can treatment with medicinal cannabis be helpful in diseases in which hormones play a role. In the relatively new field of medical cannabis research, there will always be new treatment options that can help patients.