How does cannabis affect blood pressure?
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- Does marijuana lower or raise blood pressure?
- What are the cardiovascular effects of cannabis?
- Weed and blood pressure medication
- Other effects of weed on blood pressure
Since smoking a joint can lead to a relaxing high, you might wonder about cannabis use and its effect on blood pressure. We know that weed can make your eyes red , but does it also raise or lower blood pressure, or does it not have any effect at all? If you have high blood pressure, is marijuana safe to consume?
Here we’ll address how smoking weed, including medical marijuana, could factor into your blood pressure levels.
Does marijuana lower or raise blood pressure?
To answer this question, we should focus on two of the primary cannabinoids present in cannabis : cannabidiol (CBD) and tetrahydrocannabinol (THC). Both may exert an influence on blood pressure levels.
Dr. Bonni Goldstein, a medical adviser to Weedmaps and the director of Canna-Centers in Lawndale, California, outlined the potential effects of THC on blood pressure:
“THC can affect blood pressure depending on the dose, the route of administration, a person’s experience with THC, and a person’s underlying health. Healthy volunteers that took THC had an increase in heart rate and decrease in blood pressure. In studies where people used THC while lying down, they had elevated blood pressure. When they stood up, their blood pressure dropped and they experienced low blood pressure.”
These sudden drops in blood pressure, also known as white outs or green outs, may indeed be linked to cannabis use. Dr. Melanie Bone, a board-certified OB-GYN and cannabis specialist who practices in West Palm Beach, Florida, told Weedmaps that “cannabis may cause a drop in blood pressure on standing — known as postural hypotension.” This type of drop in blood pressure is not desirable, as it can cause vertigo and even fainting. So, when we talk about “lowering blood pressure,” we do not necessarily consider that effect beneficial to health.
Both THC and CBD may lower blood pressure in different ways. However, neither CBD nor THC should be considered a medical treatment for high blood pressure. Photo by: Gina Coleman/Weedmaps
And how does CBD affect blood pressure? The consensus is that CBD tends to relax the blood vessels and decrease anxiety, which ultimately leads to a lowering of blood pressure. This type of blood pressure reduction is more favorable, as it is associated with decreased levels of anxiety. Both THC and CBD may lower blood pressure in different ways. However, based on available research, neither CBD nor THC should be considered a medical treatment for high blood pressure.
What are the cardiovascular effects of cannabis?
Another frequently asked question about cannabis and cardiovascular health is: can weed cause a heart attack?
First, let’s again distinguish between the cannabinoids THC and CBD. For example, CBD oils containing trace levels of THC may have very different effects than smoking a high-THC strain of marijuana. Various studies have indicated that THC may have detrimental effects on cardiovascular health, whereas CBD could be helpful to the heart.
Goldstein added, “CBD does not appear to have the same risks for the heart as THC and in fact, appears to be somewhat cardioprotective.” To support this assertion, Goldstein cited a 2010 study published in the Journal of the American College of Cardiology in which researchers concluded that CBD has therapeutic potential in treating complications of diabetes, as well as some cardiovascular disorders. Most notably, CBD could reduce inflammation, a condition that can ultimately damage the blood vessels, arteries, and vital organs. So, if you apply CBD oil to your skin or swallow a few tablespoons, the impact could differ greatly than if you smoked a blunt.
To this point, there is some research that suggests smoking THC could directly or indirectly lead to a heart attack. One 2019 study titled “The Cardiovascular Effects of Marijuana: Are the Potential Adverse Effects Worth the High?” and published in the Journal of the Missouri State Medical Association showed that some people experienced a heart attack within an hour of smoking cannabis.
Bone, however, argued, “On careful study, many of the patients also smoked cigarettes and were obese, making it hard to draw absolute conclusions. Also, the observations were made on cannabis of unknown origin, not cannabis from a dispensary.” The fact that the cannabis did not come from a registered dispensary is significant, as there is no available lab testing to determine what other compounds may have been present.
The bottom line is that there have been studies demonstrating a questionable association between smoking weed and having a heart attack, and more research is necessary.
Weed and blood pressure medication
You might also be wondering, what if you’re smoking weed while taking blood pressure medication? Will there be an adverse reaction? If you are smoking THC-rich cannabis and taking medication for high blood pressure, the answer is that there could be.
Goldstein explained, “Smoking cannabis can be harmful for those with heart disease or hypertension since the smoke contains carbon monoxide. This gas binds to the hemoglobin in red blood cells, displacing oxygen off of the red blood cells which results in less oxygen going to the body’s tissues, including the heart. People with heart disease or high blood pressure should avoid smoking.”
Instead, Goldstein recommends other methods of cannabis use, such as sublingual tinctures or edibles, which she says are safe to use if someone is on blood pressure medication. Further, Bone stressed that people who use cannabis and are on blood pressure medications need to be mindful of the possibility of an interaction with other prescription medications. This means monitoring blood pressure and reporting any dizziness to your doctor, who can adjust your dosages accordingly.
People who use cannabis and are on blood pressure medications need to be mindful of the possibility of an interaction with other prescription medications. Photo by: Gina Coleman/Weedmaps
In particular, the blood thinner warfarin was shown in a 2017 study published in the journal Epilepsy & Behavior Case Reports to interact with cannabidiol (CBD) in certain epileptic individuals . In line with Bone’s advice, researchers concluded that patient lab work should be monitored closely.
While it is possible for warfarin and other medications to interact with cannabis, there are no guarantees, and the 2017 study focused on patients with epilepsy rather than on the general population. As Dr. Bone reported, “In my private practice, I have not encountered a significant negative interaction between blood pressure medication and cannabis.”
Other effects of weed on blood pressure
There may be other effects of marijuana on blood pressure that health practitioners have yet to discover. All potential effects depend on the individual’s existing health problems, especially co-morbid conditions such as diabetes and obesity.
Can people without these conditions safely indulge in marijuana? A healthy individual’s body may appear as a well-oiled machine, but Bone disputes that analogy, pointing out that, “Unlike a car, where we replace the brakes or tires, the heart never gets a vacation and the blood vessels need to keep working forever. And the nervous system, which directs the show like a conductor, is on duty 24/7.”
Moderation, then, may be key in integrating a cannabis regimen into your healthcare plan. Consult with your physician before you begin using cannabis or CBD products and discuss any medications you are currently taking.
Learn how cannabis affects blood pressure and what questions you should ask your doctor before starting a regimen.
Marijuana and heart health: What you need to know
Access to marijuana is growing, but marijuana benefits and its risks have not been carefully studied.
Image: © UrosPoteko/Thinkstock
In many states in this country, you can legally use marijuana for a range of health benefits, including the treatment of chronic pain, anxiety, and nausea. Smoking is the fastest way to feel the effects of marijuana, which is derived from the Cannabis sativa plant. Yet marijuana smoke contains many of the same toxins, irritants, and carcinogens found in cigarette smoke — a known contributor to heart disease as well as cancer.
Marijuana cultivation and use dates back some 6,000 years. However, the cardiovascular and other health effects of cannabis aren’t well studied. That’s partly because under federal law, cannabis is a Schedule I substance, meaning it has “no currently accepted medical use and a high potential for abuse.” That designation places numerous restrictions on researchers, making it difficult to carry out rigorous research on marijuana.
“As a result, everything we’re told about what marijuana does or doesn’t do should be viewed with a certain amount of caution. This holds equally true for the risks as well as the benefits,” says Dr. Kenneth Mukamal, associate professor of medicine at Harvard-affiliated Beth Israel Deaconess Medical Center.
Pot and pain
Some of the strongest evidence supporting the medical use of marijuana is marijuana’s benefits for managing chronic pain. Cannabinoid compounds (see “Cannabis 101”) interact with receptors in nerve cells to slow down pain impulses and ease discomfort. Cannabinoids also have been shown to be effective in quelling nausea and vomiting. In addition, marijuana is a powerful appetite inducer. The combination of these attributes makes marijuana a therapeutic option for people coping with the side effects of chemotherapy and others who are in danger of unintended weight loss. However, in conditions where gaining extra weight might exacerbate existing health problems, such as diabetes, appetite stimulation would be counterproductive.
One of the few things scientists know for sure about marijuana and cardiovascular health is that people with established heart disease who are under stress develop chest pain more quickly if they have been smoking marijuana than they would have otherwise. This is because of complex effects cannabinoids have on the cardiovascular system, including raising resting heart rate, dilating blood vessels, and making the heart pump harder. Research suggests that the risk of heart attack is several times higher in the hour after smoking marijuana than it would be normally. While this does not pose a significant threat to people who have minimal cardiovascular risk, it should be a red flag for anyone with a history of heart disease. Although the evidence is weaker, there are also links to a higher risk of atrial fibrillation or ischemic stroke immediately following marijuana use. Consistent with these links, studies by Dr. Mukamal and colleagues also suggest that marijuana smoking may increase the long-term death rate among heart attack survivors.
Questions remain on marijuana’s benefits and risks
Most of the evidence linking marijuana to heart attack and stroke is based on reports from people who smoked it. So it’s hard to separate the effects of cannabinoid compounds on the cardiovascular system from the hazards posed by the irritants and carcinogens contained in the smoke. Because cannabis smoke is known to cause airway inflammation, wheezing, and chest tightness, people with lung diseases should not smoke it. Other people who should just say no to marijuana include those who may be vulnerable to developing schizophrenia or addiction.
The cannabis plant contains more than 100 unique chemical components classified as cannabinoids. These are the active ingredients that bind to specific receptors in the brain and other parts of the body. The two most prevalent types are tetrahydrocannabinol (THC), which is primarily responsible for the mind-altering properties sought out by recreational users, and cannabidiol (CBD), which has no psychoactive effect. Cannabidiol may actually work to offset the psychoactive properties of THC.
The magnitude of marijuana’s psychoactive effect depends on the THC level in the particular strain of plant, which parts of the plant are used, and the route through which the drug enters the body. Legalization in some states has led to the breeding of strains that are three to seven times more potent than those available three decades ago.
The impact of smoked or inhaled marijuana is generally felt within a few minutes and lasts two to four hours. Marijuana ingested in food or beverages kicks in more slowly and lasts longer.
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