Evidence based

CBD and High Blood Pressure: Current Research and Understanding

What are the effects of CBD on blood pressure? Here we review the medical research to see how CBD works for hypertension.

Article By
Tracey Roizman , posted 1 month ago

Can CBD be used to help manage high blood pressure?

Keeping your blood pressure within optimal limits is vital for maintaining good health. If we allow blood pressure to go too high, it can lead to serious long-term consequences on health and wellbeing.

Whether you’re asleep, surfing the internet, stressed out, or running a marathon, your body is busy behind the scenes adjusting your blood pressure to meet the minute-by-minute demands of the body.

High blood pressure (hypertension) is one of the most problematic health issues our society faces today. It’s reached epidemic proportions in the U.S. — affecting nearly half of the adult population, according to the American Heart Association.

In this article, we explore the connection between CBD and high blood pressure. Well, cover what current research says about the use of CBD as a health supplement for high blood pressure, and what its limitations are.

  • Table of Contents

First of All, Whats a Healthy Blood Pressure?

Healthy resting blood pressure should be below 120 mmHg (systolic) and below 80 mmHg (diastolic), according to the Mayo Clinic — which defines the following categories of hypertension:

  • Healthy Blood Pressure — 120/80 mmHg
  • High Blood Pressure — 120–129/80 mmHg
  • Stage 1 Hypertension — 130-139/80–89 mmHg
  • Stage 2 Hypertension — over 140/90 mmHg

Summary: How CBD May Help

CBD may help regulate blood pressure in the following ways:

  • Relaxes the blood vessels [1,2]
  • Acts on control centers within the brain [3,4] and the peripheral nervous system [5]
  • Acts on certain genes that control blood pressure [1]
  • Regulation of nerve cell signaling involved with blood pressure control [6]

The Role of the Endocannabinoid Receptors in Controlling Blood Pressure

Distributed throughout your brain and body is an intricate network of cannabinoid receptors and their respective messenger molecules (endocannabinoids) that comprise what is known as the endocannabinoid system (ECS). Your ECS is vital for maintaining optimal function of your organs and systems at all times — a process known as homeostasis.

There are two main types of receptors for cannabinoid molecules: CB1 and CB2. These two receptors have separate distributions throughout your body and different functions with regard to maintaining blood pressure.

1. CB1 Receptors

CB1 receptors are especially abundant in the neurological system and areas of the body where blood pressure is regulated. This includes the blood vessels, adrenal glands, heart, and lungs [7].

Most of the blood pressure modulating activity of CBD is associated with its effects on CB1 receptors.

2.CB2 Receptors

These endocannabinoid receptors are also found in the brain and nervous system but are mostly concentrated in the immune system [7].

Due to their location, CB2 receptors contribute to blood pressure regulation in times of disease or in response to acute inflammation from an infection or injury or to chronic, low-grade inflammation caused by factors like poor diet, smoking or other unhealthy lifestyle practices.

CBD & Hypertension: What the Research Says

There are feedback loops throughout your body that help regulate your blood pressure — the ECS is an essential component of most of these pathways. This may make CBD a useful therapy for conditions associated with blood pressure dysregulation.

Here are several ways CBD has been found to affect blood pressure in pre-clinical and clinical studies:

1. Anti-inflammatory and Antioxidant Activity

The anti-inflammatory and antioxidant activity of CBD provides many of its blood pressure-lowering benefits.

Preliminary animal studies have shown that CBD protects blood vessels from damage due to inflammation or elevated glucose levels that can lead to hardening of the arteries and high blood pressure [1].

CBD does this by regulating the activity of cyclooxygenase (COX), a key enzyme in the inflammatory cascade and the same enzyme anti-inflammatory drugs like Aspirin target as well [9]. COX also promotes production of prostanoid compounds that signal blood vessels to dilate (widen).

2. Effect of CBD on the Arteries

CBD may affect the arteries in a number of ways. Some of these include:

A) CBD May Promote Arterial Dilation

In an experiment using arterial tissue from laboratory animals, CBD caused nearly complete relaxation of the artery [1].

A similar experiment was performed using human arteries that were constricted prior to administering CBD, and CBD reduced the pressure in the arteries by 40% [1, 2].

Researchers noted CBD reduced blood pressure by activating CB1 receptors in the endothelium (membrane lining the inside of the heart and blood vessels). This causes the release of nitric oxide — one of the main signaling molecules that cause arteries to dilate, thus reducing blood pressure.

It also appears that CBD could work outside of the endocannabinoid system to directly manage blood pressure in arteries by inhibiting calcium channel influx in the muscular layer of arteries [6]. When calcium enters muscles it causes the muscles to contract, so by inhibiting calcium channels CBD promotes relaxation and dilation of blood vessels.

B) CBD May Inhibit Excessive Fluid Retention

Excess sodium in cells promotes water retention that can lead to elevated blood pressure. CBD prevents fluid retention by promoting potassium influx into cells [2]. 

Sodium and potassium work in opposition to each other in a similar fashion to the way water levels in a dam are controlled. When the locks to the dam are opened (analogous to potassium influx into a cell), water flows out and the water level in the dam drops. But when the locks are closed (analogous to sodium influx into a cell) the dam retains water and the water level rises.

C) CBD May Protect Against High Blood Sugar

CBD may protect arteries from the damaging effects of high blood glucose. In tissue culture experiments these effects were reduced in the presence of CBD [1].

Though the precise mechanism for these observed effects is not yet known, lowered inflammatory markers occur simultaneously with these effects — leading researchers to speculate that lowering inflammation is partly responsible for these benefits.

D) CBD May Modulate the Stress Response

There is some evidence that CBD may promote relaxation of arteries by reducing the activity of stress-response enzymes in the endothelial lining that initiates a cascade of inflammation that leads to elevated blood pressure [2].

3. Anti-Anxiety Effects of CBD

Numerous clinical trials have established CBD as an effective anti-anxiety remedy [1]. CBD is known to act on memory centers of the brain to remove traumatic memories that trigger the anxiety response [3].

Studies have also revealed that CBD may calm the cardiovascular response to anxiety. In laboratory animals, a single dose of CBD reportedly reduced elevated heart rate and blood pressure during anxiety [1].

However, human clinical trials remain inconclusive, with some reporting no significant blood pressure lowering effects in patients with anxiety disorders in spite of CBD reducing other symptoms of anxiety.

4. CBD Acts on Stress Response Centers in the Central and Peripheral Nervous Systems

A) Central Nervous System

CBD’s stress-modulating effects may be due, in part, to its activity on the limbic structures of the brain, which control the neuroendocrine response to stress. A single dose of CBD protected healthy volunteers from the blood pressure elevating effects of stress in one clinical trial [4].

By dampening the stress response CBD may prevent dangerous spikes in blood pressure that occur in stressful situations and can increase the risk for cardiovascular disease that can lead to stroke or heart attack.

B) Peripheral Nervous System

CBD may offer blood pressuring lowering benefits for patients with certain forms of hypertension by reducing the activity of the sympathetic nervous system, the component of the peripheral nervous system that activates the fight or flight response to stress [5].

5. Gene Modulating Effects of CBD for Hypertension

Early evidence shows CBD may activate a gene involved in fat and glucose metabolism ( PPARγ).

PPARγ decreases inflammation in endothelial cells and reduces atherosclerosis, which leads to relaxation of the arteries. This gene also increases the activity of a high-powered antioxidant called superoxide dismutase, SOD — which promotes the dilation of arteries by reducing inflammation-inducing free radicals [1].

When CBD May Increase Blood Pressure

Following injuries from low-oxygen conditions, such as stroke or heart attack, the body’s ability to maintain blood pressure is often impaired, leading to episodes of dangerously low blood pressure. CBD has been found to help elevate blood pressure under these circumstances [10].

In some situations, CBD may inhibit the dilation of blood vessels, thereby preventing blood pressure from dropping. For example, toxic lipopolysaccharide compounds on the surface of bacteria are known to cause blood vessels to dilate. Under experimental conditions, it’s been found that CBD stops this response [1].

CBD Activity in Normal Conditions

If your blood pressure is not elevated, there is some evidence in both animals and humans that CBD might not cause your blood pressure to drop. This has been found to be true whether it’s used short term or for prolonged periods of time [5,10,11].

It appears CBD only lowers blood pressure in people who are hypertensive — however, anecdotal reports suggest CBD may lower blood pressure in healthy people as well.

If you suffer from low blood pressure, speak with a doctor before using CBD — there’s a chance this supplement will lower blood pressure too much. This can lead to lightheadedness and fainting.

Important Things to Consider When Using CBD With High Blood Pressure

Research into the health effects of CBD is very much in the early stages. And, as with many avenues of scientific inquiry, the more we learn about the role of CBD in maintaining blood pressure, the more we begin to understand how much more there is to know about this very complex process and how much we don’t yet understand.

Although CBD has a high safety profile, it’s important to keep in mind that anything that has effects on the body will also have unintended or undesirable side effects. Where CBD and blood pressure are concerned, it’s helpful to consider the following:

1. CBD Responds Differently In Everybody

The published literature shows that a diverse range of factors can affect response to CBD. In a small clinical trial, response ranged from 2 to 75% relaxation of arteries [2]. However, the precise mechanisms for many of these differences are not known at this time.

In general, women seem to have a greater response than men and response rates vary considerably among species of animals used in laboratory studies [10].

2. The Effects of CBD Can Change Depending on Underlying Health Conditions

Patients with movement disorders associated with elevated blood pressure were reported to have a significant decrease in their standing blood pressure when they took CBD over a period of 6 weeks [10].

Conversely, some conditions may reduce your response to CBD, notably type-2 diabetes and elevated cholesterol. No changes in blood pressure were noted in response to CBD in patients with epilepsy who took CBD for 4.5 months, or in patients with Huntington’s disease who took CBD for 6 weeks [10].

However, age, body mass index (BMI), and smoking do not seem to have an effect on CBD response. Likewise, having cancer, heart disease, or hypertension did not impact participants’ response to CBD [10].

3. Drug-Drug Interactions May Occur

Some drugs can impair CBD activity. For example, beta-blockers used for managing high blood pressure, statins for high cholesterol and some blood sugar lowering medications have been known to reduce response to CBD [10].

Summing it All Up: CBD & High Blood Pressure

Blood pressure is maintained by an intricate system of feedback loops, and CBD receptors are present in many of these structures.

From the available research, these generalizations can be made:

  • CBD acts through the endocannabinoid system to regulate blood pressure
  • CBD is an antioxidant and anti-inflammatory — both of which have a positive impact on high blood pressure
  • CBD acts on the blood vessels directly to reduce blood pressure
  • CBD supports anxiety symptoms which can lower blood pressure
  • CBD activates genes involved with inflammation and blood pressure response

However, while CBD shows great promise as an effective supplement for maintaining healthy blood pressure, the science on CBD for managing hypertension is still in early phases, making it difficult to draw conclusions about who can benefit or when CBD might be indicated for lowering blood pressure.

Although there’s a lot of evidence that CBD could be an excellent natural health supplement for controlling high blood pressure — it’s important you speak with your doctor before using this substance if you have any issues with blood pressure control. This is especially important if you’re taking any medications or supplements to manage your condition, or if you have a family history of stroke or heart disease.


References

  1. Stanley, C. P., Hind, W. H., & O’Sullivan, S. E. (2013). Is the cardiovascular system a therapeutic target for cannabidiol? Br J Clin Pharmacol, 75(2), 313-322. doi:10.1111/j.1365-2125.2012.04351.x
  2. Stanley, C. P., Hind, W. H., Tufarelli, C., & O’Sullivan, S. E. (2015). Cannabidiol causes endothelium-dependent vasorelaxation of human mesenteric arteries via CB1 activation. Cardiovasc Res, 107(4), 568-578. doi:10.1093/cvr/cvv179
  3. Lee, J. L. C., Bertoglio, L. J., Guimaraes, F. S., & Stevenson, C. W. (2017). Cannabidiol regulation of emotion and emotional memory processing: relevance for treating anxiety-related and substance abuse disorders. Br J Pharmacol, 174(19), 3242-3256. doi:10.1111/bph.13724
  4. Jadoon, K. A., Tan, G. D., & O’Sullivan, S. E. (2017). A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study. JCI Insight, 2(12). doi:10.1172/jci.insight.93760
  5. Kossakowski, R., Schlicker, E., Toczek, M., Weresa, J., & Malinowska, B. (2019). Cannabidiol Affects the Bezold-Jarisch Reflex via TRPV1 and 5-HT3 Receptors and Has Peripheral Sympathomimetic Effects in Spontaneously Hypertensive and Normotensive Rats. Front Pharmacol, 10, 500. doi:10.3389/fphar.2019.00500
  6. O’Sullivan, S. E., Sun, Y., Bennett, A. J., Randall, M. D., & Kendall, D. A. (2009). Time-dependent vascular actions of cannabidiol in the rat aorta. Eur J Pharmacol, 612(1-3), 61-68. doi:10.1016/j.ejphar.2009.03.010
  7. Jahan P. Marcu, J. B. S. (2016). Chapter 66  Molecular Pharmacology of CB1 and CB2 Cannabinoid Receptors In Neuropathology of Drug Addictions and Substance Misuse, Volume 1: Elsevier.
  8. Kozlowska, H., Baranowska, M., Schlicker, E., Kozlowski, M., Laudanski, J., & Malinowska, B. (2007). Identification of the vasodilatory endothelial cannabinoid receptor in the human pulmonary artery. J Hypertens, 25(11), 2240-2248. doi:10.1097/HJH.0b013e3282ef7a0a
  9. Wheal, A. J., Cipriano, M., Fowler, C. J., Randall, M. D., & O’Sullivan, S. E. (2014). Cannabidiol improves vasorelaxation in Zucker diabetic fatty rats through cyclooxygenase activation. J Pharmacol Exp Ther, 351(2), 457-466. doi:10.1124/jpet.114.217125
  10. Sultan, S. R., Millar, S. A., England, T. J., & O’Sullivan, S. E. (2017). A Systematic Review and Meta-Analysis of the Haemodynamic Effects of Cannabidiol. Front Pharmacol, 8, 81. doi:10.3389/fphar.2017.00081
  11. Martin-Santos, R., Crippa, J. A., Batalla, A., Bhattacharyya, S., Atakan, Z., Borgwardt, S., . . . McGuire, P. K. (2012). Acute effects of a single, oral dose of d9-tetrahydrocannabinol (THC) and cannabidiol (CBD) administration in healthy volunteers. Curr Pharm Des, 18(32), 4966-4979. doi:10.2174/138161212802884780

Conditions that may respond to cannabidiol