Thanks to a growing body of research into the health benefits of cannabidiol (CBD) and other cannabinoids, a picture is beginning to emerge of the numerous biological processes that are influenced by these incredible compounds. Additionally, scientists are starting to realise that many of these processes follow daily cycles, which means that using cannabinoids at different times of the day or night can have a major impact on their efficacy. Accordingly, new research shows that taking CBD just before bed significantly increases its capacity to lower blood pressure and treat hypertension.
Harnessing The Body Clock
At the cutting edge of medicine is a relatively new and incredibly exciting modality called chronotherapy, which takes into account the body’s natural rhythms in order to ensure that medications are administered at the most appropriate time of the day. Also known as the circadian rhythm, the body’s daily ebb and flow is produced by the temporary activation of many different genes at various times of day, and controls everything from the sleep-wake cycle to blood pressure.
High blood pressure – also known as hypertension – is one of the most pressing health issues in Western societies, and is a major cause of heart attacks and strokes. Numerous studies have found CBD to be effective at lowering blood pressure when taken in the morning[i], although a newly published PhD thesis by Aidan Murray from the University of Guelph indicates that taking CBD at night is considerably more beneficial[ii].
In Murray’s study, mice were given CBD at different times of the day, with results showing that those who received the cannabinoid just before going to sleep experienced the biggest reductions in blood pressure. In fact, when taken at night, CBD was found to lower blood pressure to the same degree as common pharmaceutical drugs for hypertension.
How Does CBD Lower Blood Pressure?
CBD works via a wide range of different molecular targets, many of which are associated with the circadian rhythm. For instance, previous research has shown that it interacts with peroxisome proliferator-activated receptors (Pparg) in order to cause arteries to relax, thereby lowering blood pressure[iii]. According to Murray’s thesis, the genes that control Pparg activity in the heart and aortic tissues are upregulated at night, which partially explains why CBD is so much more effective when taken just before bed.
Other studies have shown that CBD helps to prevent blood pressure increases during times of stress, by interacting with a serotonin receptor called 5-HT1A[iv]. Once again, the gene that regulates this receptor in cardiovascular tissue tends to be expressed more during sleep than during waking time, which means that this particular effect of CBD is also likely to be enhanced at night.
Much more research is required in order to fully reveal the mechanisms by which CBD helps to treat hypertension, although there is already strong evidence to suggest that it protects blood vessels from the damage that can be caused by high blood glucose levels or inflammation[v].
As chronotherapy continues to develop, a greater understanding of how these effects fluctuate throughout the day will surely lead to more targeting treatment regimes, with specific cannabinoids being taken at different times of the day. For now, though, anyone suffering from hypertension should certainly pay attention to Murray’s concluding remarks: “Based on the results of our study, it is possible that giving CBD to humans prior to sleep time as opposed to in the morning may have resulted in an even greater reduction in resting blood pressure.”
[i] Jadoon KA, Tan GD, O’Sullivan SE. A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study. JCI insight. 2017 Jun 15;2(12). – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5470879/
[ii] Murray A. Circadian Medicine: Cannabinoid Chronotherapy for Treatment of Hypertension (Doctoral dissertation). – https://atrium.lib.uoguelph.ca/xmlui/bitstream/handle/10214/21170/Murray_Aidan_202009_MSc.pdf?sequence=1&isAllowed=y
[iii] Baranowska-Kuczko M, Kozłowska H, Kloza M, Sadowska O, Kozłowski M, Kusaczuk M, Kasacka I, Malinowska B. Vasodilatory effects of cannabidiol in human pulmonary and rat small mesenteric arteries: Modification by hypertension and the potential pharmacological opportunities. Journal of Hypertension. 2020 May;38(5):896. – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7170434/
[iv] Resstel LB, Tavares RF, Lisboa SF, Joca SR, Corrêa FM, Guimarães FS. 5‐HT1A receptors are involved in the cannabidiol‐induced attenuation of behavioural and cardiovascular responses to acute restraint stress in rats. British journal of pharmacology. 2009 Jan;156(1):181-8. – https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/j.1476-5381.2008.00046.x
[v] Stanley CP, Hind WH, O’Sullivan SE. Is the cardiovascular system a therapeutic target for cannabidiol?. British journal of clinical pharmacology. 2013 Feb;75(2):313-22. – https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2125.2012.04351.x