In recent years, CBD oil has been called the 'miracle of the modern age'. But what is CBD, and can CBD products help the heart? Consuming cannabis products doesn't have the same effects on the respiratory system as smoking it – but are edibles bad for your heart? CBD oil is made from cannabis plants but won’t make you high. Still, this natural supplement could interact with some heart medicines. Find out what you need to know before you try CBD oil for heart failure.
CBD: What is it, and can it help the heart?
CBD is the latest health craze to sweep the high street, with claims it can help everything from chronic pain and inflammation to anxiety. But what is CBD, and can it really help the heart? Emily Ray finds out.
What is CBD, and is it legal in the UK?
CBD, or cannabidiol, is a chemical that’s extracted from the leaves and flowers of the cannabis plant. Cannabis itself is an illegal class B drug, as is the compound THC (tetrahydrocannabinol) which it contains. But pure CBD isn’t illegal, as it doesn’t cause the intoxicating effects of cannabis.
What CBD products are available?
The choice of CBD products has exploded recently: you can buy oils, capsules, muscle gels, sprays and oral drops, as well as beer, tea, sweets, hummus and even CBD-infused clothing.
Many of these can be easily picked up from reputable high street stores, such as Holland & Barrett or Boots.
Prices can be high: a 500mg bottle of CBD oil oral drops could set you back as much as £45. Not that this has put people off: over the past two years, sales of CBD have almost doubled in the UK, putting regular users at an estimated quarter of a million.
What is CBD used for?
A 2018 report by the World Health Organization suggested that CBD may help treat symptoms relating to conditions such as cancer, Parkinson’s disease, multiple sclerosis (MS), anxiety, depression, insomnia and Alzheimer’s disease.
However, it also notes that this research is still in the early stages, and that more studies are needed before conclusions can be drawn on whether CBD is effective.
CBD’s popularity has been given a boost by the fact that two CBD-containing medicines have been approved for prescription use by the NHS in England: Epidyolex, which has been found to reduce the number of seizures in children with severe epilepsy, and Sativex, which contains a mixture of CBD and THC, and is licensed for treatment of muscle stiffness and spasms in people with MS.
Does CBD work?
Harry Sumnall, Professor in Substance Use at Liverpool John Moores University, says: “In terms of the products found in shops, there’s virtually no evidence to support the claims made for a lot of them. There’s a lot of marketing that says CBD is a ‘miracle of the modern age’; however, the marketing has actually overtaken the evidence of what it’s effective for.”
“In terms of the products found in shops, there’s virtually no evidence to support the claims made for a lot of them.”
Harry Sumnall, Professor in Substance Use at Liverpool John Moores University
Professor Sumnall argues that while it could be effective for some people, in some of these cases the results could be caused by the placebo effect (where the patient’s belief in a treatment makes them feel better). The placebo effect can be powerful, but Professor Sumnall warns that if people try CBD oil instead of speaking to their doctor, it could cause a problem.
The biggest difference between CBD used in clinical trials and in stores is the dose. Research has shown that some products contain very little CBD (or even none at all). Others contain THC or other illegal drugs, or even alcohol instead of CBD. By contrast, in clinical trials the CBD is purified, manufactured to a very high standard and given at a much higher dose. It is also taken regularly and under medical supervision.
Since 2016, any CBD product that is presented as having medicinal value must be licensed and regulated as a medicine, regardless of whether it is actually effective. Manufacturers must follow very specific and robust rules around production, packaging and the information provided.
But so far, Professor Sumnall points out, CBD products in shops are marketed as food supplements, not medicines, so none of them have gone through this process.
Can CBD help the heart?
Inflammation is part of the process that leads to many diseases, including coronary heart disease, high blood pressure and stroke, and there is some evidence that CBD has anti-inflammatory properties. Other studies have suggested that CBD can have a protective effect on the heart: this has been proven in rats after a heart attack and in mice with some of the heart damage associated with diabetes. But because these studies are often based on findings in a lab or in animals, not in humans, we cannot yet be confident that CBD will benefit the human heart.
There is ongoing research into the use of purer forms of CBD for a variety of conditions, including heart and circulatory diseases and, in particular, diseases of the heart muscle, including myocarditis and some types of cardiomyopathy.
Some of this work is still in animals, and much more research is needed before we can definitively say that CBD can help in this area.
“It’s clear that CBD has potential,” says Professor Sumnall, “but we’re at a very early stage of that research.”
- Always talk to your doctor if you’re thinking about taking a CBD product to supplement your existing treatment.
Meet the expert
Harry Sumnall is a Professor in Substance Use at the Public Health Institute, Liverpool John Moores University. He was a member of the UK Government’s Advisory Council on the Misuse of Drugs between 2011 and 2019.
Are edibles bad for your heart?
Consuming cannabis products doesn’t have the same effects on the respiratory system as smoking it – but are edibles bad for your heart?
Cannabis, which is derived from the hemp plant, is widely known for its psychoactive and anti-nausea properties. The active ingredient in cannabis that is associated with these effects is delta-9-tetrahydrocannabinol (THC). Cannabis and synthetic cannabinoids, which are chemicals that mimic the structure of THC, can be prescribed to treat a variety of conditions, including chemotherapy-induced nausea and vomiting, chronic pain, and appetite loss. 1
A growing number of governments are legalizing the use of medical and recreational cannabis, and in turn, more research is being done on the potential risks, benefits, and medicinal uses of cannabis.
Smoking cannabis versus consuming cannabis edibles
Cannabis is available in a variety of forms; two of these include inhaling cannabis smoke, and consuming edible products or baked goods containing cannabis. Smoking cannabis may be associated with respiratory side effects because inhaling any smoke can be difficult on the lungs. 2 Some research suggests that smoking cannabis may be associated with some adverse cardiovascular effects, although more research is needed to confirm these findings. 3,4,5
Consuming edible cannabis products does not have the same effects on the respiratory system as smoking cannabis; however, there is minimal research on whether edibles can impact the cardiovascular system. This has been indicated as a possibility. For example, one case study of a 70 year old man with coronary artery disease described his myocardial infarction, or heart attack, shortly after consuming a cannabis-infused lollipop. 6
The patient consumed more than three-quarters of a 90-mg marijuana lollipop. The patient described experiencing fearful hallucinations and called a family member to take him to an emergency room. He also reported crushing chest pain, sweating, and shaking. The patient was treated for a heart attack with an anticoagulant, antiplatelet, and aspirin.
Cannabinoids and the cardiovascular system
Cannabinoids, such as THC, cannabinol (CBN), and cannabidiol (CBD), found in the cannabis plant, bind to endocannabinoid receptors in the body. 7 These receptors are found all throughout the body, and as a result, cannabis can have a variety of effects for individuals. More specifically, according to some new case studies and research, cannabinoids including THC may influence the cardiovascular system itself and could potentially be associated with increased blood pressure, heart rate, and an increased risk of adverse cardiovascular events. 7
Can edibles increase heart rate?
Although the exact effects of edible cannabis are not well-studied compared to inhaled cannabis smoke, some research shows that activation of the endocannabinoid receptors may be associated with increased blood pressure and an increase in heart rate. 8 However, other research shows that activation of certain cannabinoid receptors may be associated with decreased blood pressure and heart rate, and the current evidence is fairly inconclusive. 9 More research is needed to determine whether cannabinoids can increase blood pressure and heart rate as well as determine whether these effects are specific to certain methods of cannabis ingestion.
Are edibles bad for your heart?
Although some evidence suggests that smoking cannabis may be associated with adverse side effects and cardiovascular changes, there is currently no consensus on whether or not cannabinoids such as THC and CBD are bad for the cardiovascular system. More research is needed to determine the potential impacts of cannabis and cannabis edibles on the cardiovascular system.
CBD Oil and Heart Failure
Could CBD oil ease your heart failure symptoms or help you manage your condition? This herbal supplement is sold over the counter and may be marketed with various health claims, but heart experts aren’t so sure it’s worthwhile or even safe if you have heart failure.
“Heart failure patients should know that while CBD has been touted as a wonder compound and seems to be in almost everything these days, it has never been shown to have any significant cardiovascular benefits in human studies,” says Scott Lundgren, DO, a transplant cardiologist at Nebraska Medicine in Omaha.
What Is CBD Oil?
CBD oil contains cannabidiol, an herbal liquid supplement made from the cannabis plant. It doesn’t have the same effect on the brain as THC, another compound found in cannabis that gives you a “high” when smoked or eaten, says Larry Allen, MD, associate division head for clinical affairs in cardiology at University of Colorado Anschutz Medical Campus.
“There are no known cardiovascular benefits for cannabis or cannabidiol, and there may even be some adverse effects, so people should not take these products and think that it will have positive effects on their cardiovascular health,” says Allen, who’s also co-author of the American Heart Association’s statement on all cannabis products.
In 2018, the FDA approved the first oral, purified CBD drug, Epidiolex, to treat seizures in two rare forms of epilepsy. Two synthetic versions of cannabiinds are also approved: dronabinol (Marinol, Syndros) for treatment of nausea during cancer chemotherapy and nabilone (Cesamet) to treat weight loss associated with AIDS. Marinol is synthetic THC
Some of CBD’s proven benefits in other health conditions may be intriguing to people living with heart failure, Allen says.
“Does it stimulate your appetite? Yes. Do people gain weight if they take it? Possibly true. Patients with severe heart failure do have cachexia,” or severe weight loss and muscle wasting, he says. “One could argue that people with nausea, lack of appetite, or who are losing weight could think CBD would help them. People with heart failure have a fair amount of discomfort, including edema [swelling] and somatic or pain-related issues, so you could think CBD has a role.”
But there isn’t really any evidence to prove that it will relieve heart failure symptoms or be safe to use if you have heart failure, he adds.
What We Know About CBD
Some research suggests that CBD oil may improve some heart-related symptoms:
- A very small study conducted in 2017 in England found that CBD improved resting blood pressure and blood pressure spikes related to stress in people without heart conditions.
- Various studies in animals have shown that CBD could improve vasorelaxation, or opening of arteries for better blood flow, as well as reduce inflammation. A small clinical trial from Mexico studying CBD in people with heart failure hasn’t reported any results yet.
- A large study of more than 161,000 people hospitalized for heart failure who had used marijuana found that they had, on average, a lower risk of death and shorter hospital stays. But this doesn’t necessarily mean CBD oil would have the same benefit.
It’s illegal in the U.S. to market CBD by adding it to any food or calling it a dietary supplement. Also, although the FDA has approved a few CBD drugs to treat certain diseases, don’t expect CBD sold over the counter to be safe or beneficial for heart failure, Lundgren says.
“CBD oil may not have the same properties, and it can actually cause gastrointestinal distress like diarrhea or cause decreased appetite. CBD products can include unknown ingredients and may not be accurately labeled,” he says.
When you use CBD oil, your liver breaks it down. During this process, it could interfere with your medications for heart failure or other heart conditions. “CBD has known interactions with warfarin, certain statins, calcium channel blockers, beta-blockers, and nitrates. Just because a supplement is ‘natural’ doesn’t mean that it is safe,” Lundgren says.
CBD May Have Health Risks
CBD oil must be studied in randomized clinical trials on people, not animals, before it can be considered safe or effective for heart failure, Lundgren says. Until that happens, he advises against buying or using CBD. “There is some evidence that CBD can cause liver injury as well as lead to male infertility issues. When consumed with alcohol, individuals may experience increased drowsiness, which can lead to household injuries.”
If you have heart failure, you might feel like you’re taking control of your own care by trying herbal treatments that don’t require a prescription. To be safe, talk to your cardiologist first: Ask questions about CBD oil and make decisions together about using this or any other supplement, Allen says.
“CBD products cost money and can distract you from taking prescribed treatments for heart failure that are evidence-based. They could do indirect harm to people with heart failure. . We already have a half-dozen treatments for heart failure symptoms and to help you live longer.”
Larry Allen, MD, MHS, University of Colorado Anschutz Medical Campus.
Scott Lundgren, DO, Nebraska Medicine.
FDA: “What You Need to Know (And What We’re Working to Find Out) About Products Containing Cannabis or Cannabis-derived Compounds, Including CBD,” “FDA Approves First Drug Comprised of an Active Ingredient Derived from Marijuana to Treat Rare, Severe Forms of Epilepsy,” “FDA and Cannabis: Research and Drug Approval Process.”
JCI Insight: “A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study.”
Oxidative Medicine and Cellular Longevity: “Therapeutic Applications of Cannabinoids in Cardiomyopathy and Heart Failure.”
Cannabis and Cannabinoid Research: “An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies.”
ClinicalTrials.gov: “Cannabidiol in Patients With Heart Failure in AHA/ACC Stages A-C (CAPITAL-AC).” NCT03634189.
Journal of Cardiac Failure: “Marijuana Use is Associated with Better Hospital Outcome in Patients with Acute Heart Failure: A Propensity Match Analysis from National Inpatient Database.”