Cannabidiol’s Interesting New Role in Cardiovascular Health

The statements mentioned in this content have not been evaluated by the FDA, and are not intended to prevent, diagnosis, or treat any disease. Always work with your personal healthcare provider.

Worldwide, cardiovascular disease is the number one cause of death with 17.9 million people dying annually from disorders that fall into this category^.1 Lifestyle choices such as the amount you exercise or the number of processed and sugary foods you eat play a huge role in whether or not your heart is healthy. However, there’s a lot of evidence—particularly in cell culture and animal studies—that suggests CBD may support cardiovascular health together with making other lifestyle choices that keep your heart healthy.

The Endocannabinoid System and Strokes

After strokes, changes occur in the endocannabinoid system. In the brains of rats, there’s an increase in the expression of cannabinoid (CB)1 and CB2 receptors, suggesting that the endocannabinoid system is involved in the body’s response to stroke.²

In addition, evidence from humans and animals found elevated levels of the endocannabinoids anandamide (AEA), oleoylethanolamide (OEA), and palmitoylethanolamide (PEA) in neurons.² As you may recall from previous chapters, endocannabinoids are cannabinoids your body makes naturally.

To cause strokes in rodents, researchers block blood flow to the cerebral artery. Doing this leads to dead tissue in areas deprived of blood. This dead tissue is known as an infarct. By measuring  how big the infarct is before and after giving the animals a particular substance, researchers can tell if that substance is able to reduce the infarct size and heal damaged tissue. In animal studies, CBD reduced the infarct size, suggesting it may stop damage from strokes.^2,3

In animal studies, CBD also reduces the neural damage caused by strokes.^3,4 It’s a powerful antioxidant that protects brain cells from death. In fact, researchers found that it’s a stronger antioxidant than vitamin C or alpha-tocopherol (vitamin E).⁵ Another way in which CBD protects neurons is by acting on serotonin receptors. These receptors are involved in both the widening of blood vessels (vasodilation) and protecting neurons in the brain.^6,7 CBD also boosts blood flow to the brain.⁶ And it supports a healthy inflammatory response in neurons.⁴

Cannabidiol and Artery Health

CBD may support the health of the arteries by blocking the breakdown of beneficial endocannabinoids the body produces naturally.⁸ CBD boosts levels of the anti-inflammatory endocannabinoid anandamide while stopping a rise in the proinflammatory endocannabinoid 2-AG.⁸ This allows these endocannabinoids to beneficially react with CB receptors on immune cells known as neutrophils and macrophages, which stops them from contributing to atherosclerotic plaques.⁸ 

In addition, CBD may assist in the relaxation human arteries.⁹ It does this in part by activating the CB1 receptors and stimulating the release of nitric oxide.^9,10 Balanced levels of nitric oxide are important for arterial health.

CBD also relaxes arteries by interacting with peroxisome proliferator-activated receptors (PPARγ).¹⁰ Activating these receptors is known to boost cardiovascular health by increasing nitric oxide and reducing blood pressure and atherosclerosis (“hardening of the arteries”).¹⁰ Activating PPARγ can support a healthy inflammatory response by blocking pro-inflammatory proteins known as cytokines and triggering the production of anti-inflammatory cytokines.¹⁰

However, one of the main ways in which CBD relaxes the arteries may be by acting as a natural calcium channel inhibitor.¹¹ Calcium channel blockers support healthy blood pressure levels by stopping calcium from entering heart and artery cells. Because calcium triggers strong contractions in the heart and arteries, the presence of calcium can lead to constricted blood vessels. Calcium channel blockers relax and widen blood vessels.

CBD and Heart Health

CBD may be able to support the health of coronary artery tissue deprived of oxygen.¹² When coronary arteries are starved of oxygen (ischemia) and then exposed to oxygen once again (reperfusion), they undergo damage. The damage causes an infarct (dead tissue). This is what happens during and after a heart attack. Heart rhythm also becomes irregular when coronary arteries don’t get enough oxygen.

In a rodent study, rats received either a control substance or intravenous CBD 10 minutes before their coronary arteries were blocked and 10 minutes before reperfusion.¹² When administered prior to oxygen deprivation, CBD dose dependently reduced the total number of arrhythmias caused by ischemia and the infarct size. In addition, CBD reduced the infarct size when it was given before reperfusion. When researchers gave CBD to the rodents before they blocked the animal’s arteries, it also reduced the number of blood platelets that stuck together (platelet aggregation) compared with animals given the control. Platelet aggregation is involved in the development of coronary artery disease. However, in this study, CBD had no effect on another factor involved in coronary artery disease, mast cell degeneration.

Another rodent study came to a similar conclusion. In this study, CBD also reduced the infarct size in rats after the animals’ coronary arteries were deprived of oxygen and then reperfused with oxygen once again.¹³ In this study, the beneficial actions of CBD were due to its ability to support a healthy inflammatory response in not only the heart, but also the body.

CBD Maintains Healthy Blood Pressure When Under Stress

As I discussed in Chapter Three, CBD calms people down when exposed to stress. High stress levels can lead to hypertension. Several human studies found that CBD can support healthy blood pressure levels during stressful situations. In a randomized, placebo-controlled, double-blind, crossover study, nine healthy men used 600 mg of CBD or a placebo.¹⁴ A crossover study is where scientists place the subjects on one protocol (in this case CBD supplementation) for a specific time and then switch the subjects to the placebo for another period of time. To cause stress in the subjects, the researchers exposed them to cold and exercise and gave them a test designed to produce mental stress.

Diastolic and systolic blood pressure fell significantly immediately following the stress test in men who had taken CBD. After exposure to cold, men in the CBD group experienced a pronounced drop in systolic blood pressure and mean arterial pressure. The researchers also found that diastolic blood pressure was significantly less in the men given CBD during cold stress. During exercise stress, CBD lowered systolic blood pressure and mean arterial pressure.

For a longer discussion of the way CBD may support healthy blood pressure in people under stress, please review Chapter Three of this book.

Diabetic Heart Health

Diabetes is an important risk factor for atherosclerosis, stroke, and coronary heart disease. In fact, cardiovascular problems are the main cause of morbidity and mortality in people with diabetes.¹⁵ High blood sugar is highly damaging to the cardiovascular system. It triggers a number of harmful processes such as the production of too many reactive oxygen species and reactive nitrogen species and advanced glycation end products (AGEs).¹⁶

Diabetes is associated with damage to small (microvascular) and large (macrovascular) blood vessels and arteries. The most common macrovascular complication of diabetes is atherosclerosis, which ramps up the risk for strokes, heart attacks, and peripheral artery disease.¹⁶ Atherosclerosis begins when immune cells known as monocytes stick to the artery lining known as the endothelium. High blood sugar encourages these monocytes to adhere to the endothelium, in part by increasing the expression of adhesion molecules ICAM-1 and VCAM-1.¹⁶

In human coronary artery endothelial cells, CBD blocked the increased activity of adhesion molecules ICAM-1 and VCAM-1 caused by high blood sugar.16 It also stopped high blood sugar from causing monocytes to stick to the artery lining.16 In addition, high blood sugar weakened the endothelial lining of the arteries, while CBD kept the arterial lining strong and healthy.¹⁶

CBD may also support heart health in people with diabetic cardiomyopathy.¹⁷ The high blood sugar and insulin levels that occur in diabetic patients lead to damaging changes in the heart’s structure. This is known as cardiomyopathy.

Researchers used a mouse model of type I diabetic cardiomyopathy and then another study using human heart cells exposed to high glucose to find out whether CBD had any beneficial effects.¹⁵ The studies found CBD supported healthy heart function and a healthy inflammatory response, as well as reduced cardiac fibrosis, oxidative/nitrative stress, and cell death. In addition, in human heart cells, CBD reduced the increased reactive oxygen species and cell death caused by high glucose. It would be nice to see human trials conducted in this area, as CBD appears to show a lot of promise.

CBD and Metabolic Syndrome

Metabolic syndrome is a collection of risk factors for heart disease, stroke, and diabetes including high blood pressure, weight gain around the abdomen, high blood sugar, and high cholesterol and triglycerides. In addition to keeping the heart healthy and blood pressure under control during stress, another way in which CBD may defend against the metabolic syndrome is by helping people manage their weight.¹⁸ CBD can reduce hunger and promote weight loss. When the hypothalamus is injured in rodents, it causes increased hunger. This is known as hyperphagia. CBD reduces hyperphagia in rats, suggesting it may reduce food intake.⁸ This in turn may help shed pounds from the abdominal area. Further supporting this idea is a human study investigating CBD in epilepsy. This study found that 28% of the subjects receiving CBD experienced a loss of appetite compared to only 5% of the controls.⁸

The bottom line? CBD may support a healthy heart and arteries and blood pressure levels already in the normal range. In my clinical practice, I find that these properties along with its ability to reduce appetite and weight make it an ideal supplement to promote the health of my patients concerned about heart health and metabolic challenges.

References:

1. Cardiovascular Diseases. World Health Organization. https://www.who.int/health-topics/cardiovascular-diseases/#tab=tab_1. Accessed September 1, 2020.
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