High blood pressure (otherwise known as hypertension) has been one of the danger signs of cardiovascular (heart) disease for decades now. It is recognised as the most important factor in predicting future illness and death. Classically it has been attributed to things like living a high stress lifestyle and recently there is a new potential treatment for high blood pressure – CBD.
Understanding how CBD might be able to lower your blood pressure is based on understanding the link between stress and hypertension.
When we talk about stress we are actually covering a very wide topic: things like social isolation, low socioeconomic status, depression, stressful family and work life, and anxiety all contribute to the feeling and biology of stress.
Many large research studies have confirmed the relationship between these factors and the increased risk of both developing and worsening existing cardiovascular disease.
Cannabidiol, or CBD is part of the cannabinoid family. These chemicals are compounds that bind to cannabinoid receptors in our body and include endo-cannabinoids (made within our body), synthetic cannabinoids and phyto-cannabinoids (found within plants such as Cannabis Sativa).
There are actually over 100 of these compounds, including both CBD and THC.
CBD has been at the centre of much new research as it has shown potential in being anti-inflammatory, anti-convulsant, anti-oxidant, anti-nausea and anxiolytic (reduces anxiety). It is this myriad of effects that has got research scientists interested in its effect on the heart and blood pressure.
CBD has multiple positive effects on your heart. Amazingly research has shown it can even reduce irregular rhythms and cardiac damage after a heart attack.
But a much more widespread application of CBD is in reducing the cardiovascular response to stress. When we become stressed, our body goes into fight or flight mode in order to protect us.
This usually floods our bodies with adrenaline, putting up our heart rate and increasing our blood pressure. This gives vital nutrients and oxygen to our muscles and brain so we have extra energy to either fight or run from the situation.
This is supposed to be a short term response however. If we live relatively stressful lives then this sustained heart rate and blood pressure puts strain on our heart, putting us at risk of things like strokes and heart attacks.
A paper published in 2017 showed for the first time that acute (as in short term) administration of CBD brought down blood pressure when someone was resting. The scientists concluded that this effect was probably down to the anxiolytic (anti-anxiety) effects of CBD.
Previous studies had not seen this effect, but likely because they did not continuously monitor their patients’ blood pressure.
What is really interesting is that CBD also showed properties in being able to reduce the effects of both physical and mental stress. When exercising or under any other form of physical stress, CBD keeps blood pressure low both before and immediately after the exercise.
All these findings come after just a single dose of CBD. In contrast with most modern medicine, the CBD was well tolerated by all the patients and there were no noted side effects or adverse events.
One of the more technical but important findings when looking at CBD and blood pressure is that it manages to bring down blood pressure without causing a spike in heart rate or a big drop in the output of the heart.
Both these factors are important for general health and safety as well as when considering interactions with other cardiac medications which may already be impacting the body in this way.
While use of CBD is generally considered very safe, there is one aspect with which care has to be taken. CBD inhibits (i.e. slows down) several important enzymes in the liver which are in charge of metabolizing much of the medication we take. The group of enzymes is known as the CYP450 family.
This can mean a build up of those medications in your body, potentially leading to unsafe levels and eventually unwanted side effects.
The reverse can also happen as well. If you are already taking a medication which affects these enzymes then your body could lose its ability to process CBD properly. This could mean less of it actually entering your system and less beneficial effects seen as a result.
If your doctor has told you not to drink grapefruit juice then you are on a CYP450 affecting drug and should consult with your doctor before taking CBD. Common drugs that are in this class include warfarin and other blood thinners such as NOACs/DOACs like Apixaban.
This is a bit of a trick question. Many websites promote CBD which apparently treats a certain condition like high blood pressure.
There is however only one form of CBD, the effects that you receive from it depend primarily on the dose and whether it is a broad spectrum CBD, full spectrum or isolate.
This is because broad spectrum CBD contains all the other natural, non-psychoactive compounds that are collected during extraction without THC. THC is known to cause increased heart rate which could put extra demands on the heart. It may be best to avoid THC if you have a history of heart disease.
CBD is rising in popularity because of the widespread untapped potential it has in treating disease. Paradoxically, because there are so many potential benefits the research looking at CBD is spread thin. There are a number of centres looking at CBD and heart health in general but only a handful looking specifically at CBD and treating high blood pressure.
The first few looked at animal models and poorly recorded the blood pressure levels, their findings have been replaced by a single paper from 2017 that consistently showed that CBD lowers blood pressure across a range of stressful environments.
CBD may only have one paper proving its effect on hypertension, but we have already proven at varying levels its good effect on reducing anxiety, inflammation, pain and more.
This supports the theory that there are multiple pathways through which CBD can lower and blood pressure and protect our heart. While it certainly won’t do any harm to trial using CBD to manage hypertension there are a few outstanding things to think about.
What really matters is how much CBD can lower blood pressure, and how much we would need to take to make that happen. We don’t know the answer to those questions.
Then there is the issue of tolerance, most people who smoke cannabis find it has less effect over time. If this is true for CBD as well then the amount our hypertension is treated could also drop over time.
Before these questions and more are answered you won’t see cardiologists replacing your standard blood pressure medication just yet. But with more research and time it does seem likely that CBD has its place in treating hypertension and within wider cardiac medicine.