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A Ray Of Hope? 

Author: Dr. Stephen Chaney 

When many people think of cannabis (both marijuana and all the edible forms containing THC, its active ingredient), they think about the highs, such as:

• Recreational use to get high.

• Pain relief.

• Relaxation and calming.

But could there also be lows associated with cannabis use?

Most people assume that cannabis is safe. This belief has been popularized in the media. It is based on a 2017 National Academies of Science, Engineering, and Medicine that concluded there was “inconclusive evidence for long-term risk.”

While National Academies reports are considered highly accurate, this one suffered from the “garbage in – garbage out” limitation. Research on the risks of cannabis use was very limited at that time.

That’s because cannabis is considered an illegal, controlled drug by the US government. That made it very difficult to get the money and the material to do large clinical studies.

However, that landscape changed dramatically after 2017. While cannabis is still considered a Schedule 1 drug at the federal level, many states have legalized its use at the state level. This led to an increased urgency to determine the risks associated with cannabis use.

More recent studies paint a gloomier picture. These studies show that cannabis use is associated with:

• Increased risk of mental health conditions such as psychosis, anxiety, depression, and schizophrenia.

• Increase risks of chronic cough, bronchitis, and asthma.

• Increase inflammation, especially in the endothelial cells lining our blood vessels.

• Decreased sperm counts in men and irregular periods, and reduced fertility in women.

• Increased risk of heart attacks, strokes, atrial fibrillation, and heart failure.

Let’s focus on the cardiovascular effects for this discussion. In a recent position paper, the American Heart Association:

• States that the health risks of cannabis use are equivalent to smoking.

• Recommends incorporating cannabis into tobacco control and prevention efforts, including age restrictions, taxes, and smoke-free policies.

Many people assume that the negative effects of cannabis on the lungs and heart are only associated with cannabis in its smokable form because the same kinds of harmful chemicals are found in cigarette smoke and marijuana smoke.

But is cannabis in edible form really safer than cannabis that is smoked? Several recent studies have suggested it isn’t, including the study (L Mohammadi et al, JAMA Cardiology, published online, May 28, 2025) I will discuss today.

The Edible Cannabis Lows

Previous studies have suggested that using cannabis edibles may be like smoking marijuana in terms of:

• Mental Health Risks – increased risk of anxiety, panic attacks, and psychosis, especially if they have a personal or family history of mental illness.

• Cardiovascular Effects – Increased risk of heart conditions such as heart attacks and strokes.

But those were all cross-sectional studies looking at associations. This study is a pilot study investigating assays that might be suitable for shorter double blind, placebo control studies.

The investigators identified an assay call flow-mediated dilation (FMD) that responds to cannabis use.

Simply put, the test involves putting a cuff on the upper arm to cut off blood flow to the arm for 5 minutes. Then ultrasound is used to test how well the arteries in the participant’s arm widens after the cuff is removed.

The FMD assay is a measure of blood vessel health. Reduced FMD is associated with an increased risk of future cardiovascular events, like heart attacks and strokes, in both healthy individuals and those with established cardiovascular disease.

The investigators enrolled 55 subjects between 18 and 50 years old in this study. None of the participants had used tobacco or vapes, and they had little exposure to secondhand smoke.

• Some reported smoking marijuana at least three times a week for the past year.

• Some reported using cannabis edibles at least three times a week for the past year.

• Some reported no cannabis use for the past year.

When compared with those reporting no cannabis use:

• RMD was decreased by 42% in the group who smoked marijuana.

• RMD was decreased by 56% in the group using cannabis edibles.

These decreases in RMD were similar to what the investigators had previously reported in a study with tobacco smokers.

The authors concluded, “Chronic cannabis smoking and THC ingestion [use of cannabis edibles] were associated with endothelial dysfunction similar to that observed in tobacco smokers, although apparently occurring via distinct mechanisms. This study enhances the understanding of the potential risks to vascular health linked to cannabis use and provides more evidence cannabis use is not benign.”

A Ray Of Hope

As I was researching this study, I came across another interesting article (T-T Wei et al, Cell, 185: 1676-1693, 2022) about the risks associated with cannabis use. It started with more “doom and gloom” about the risks of cannabis use but ended up with a ray of hope.

Let’s start with the “doom and gloom”.

There is an ongoing study in the UK called the UK Biobank Study. They started by enrolling 500,000 adults aged 40-69 between 2006 and 2010, and the study is still ongoing. They are collecting de-identified lifestyle, environmental, and genetic data and health outcomes for each participant in the study, with the goal of creating a huge database that investigators around the world can use for their studies.

These investigators utilized data from 157,331 participants in the UK Biobank study who provided data on cannabis use. There were 122,455 participants who reported never using cannabis and 11,914 who reported smoking marijuana more than once a week.

Compared to non-cannabis users, participants who smoked marijuana more than once a week:

• Increased their risk of having a heart attack by 16%.

• Increased their risk of having a heart attack before the age of 50 by 18% (This is referred to as “premature heart attack” because it is rare. It increases a person’s lifelong risk of subsequent heart attack, heart failure, and arrhythmias that can cause sudden death).

• Even more disturbing they reported that older people with type 2 diabetes, high blood pressure, and/or high cholesterol who used marijuana significantly increased their risk of having a major acute heart attack or brain event while hospitalized compared to those who didn’t use marijuana.

Now for the ray of hope!

They searched for compounds that might prevent cannabis from binding to its receptors on endothelial cells and thus prevent the cardiovascular risks of cannabis use. [In technical terms, they were looking for antagonists for the CB1 receptor].

They started with something called the SWEETLEAD chemical database. It is a database containing the structures of over 4,700 approved drugs, illegal drugs, and herbal isolates. Then they did computer simulations looking at how well each of these compounds fit into the CB1 receptor compared to four known CB1 antagonists that are currently being investigated as drug candidates to offset the cardiovascular risks associated with cannabis use.

Using this method they identified 62 possible CB1 antagonists, the best of which was genistein, a natural soybean flavonoid.

Further experiments in a mouse model of atherosclerosis suggested that genistein may block the atherosclerosis-enhancing effects of marijuana without altering its effect on the central nervous system.

The investigators concluded, “Our findings indicate that THC [the active ingredient in marijuana and cannabis edibles] induces inflammation, oxidative stress, endothelial dysfunction, and atherosclerosis through the CB1-dependent signaling pathway. Thus, CB1 antagonists could attenuate THC-induced inflammation and may prevent atherosclerosis, but the psychiatric effects [of the CB1 antagonists currently being investigated as drug candidates] are concerning.

We show that the neutral CB1 antagonist, genistein, can attenuate the adverse effects of THC on the cardiovascular system while preserving the beneficial central nervous system effects of THC…”

And in a description of the study on the Stanford Medicine website the chief investigator said, “As more states legalize recreational use of marijuana, users need to be aware that it could have cardiovascular side effects. But genistein works quite well to mitigate marijuana-induced damage of the endothelial vessels without blocking the effects marijuana has on the central nervous system, and it could be a way for medical marijuana users to protect themselves from a cardiovascular standpoint.”

The Stanford Medicine article goes on to say that. The researchers hope to conduct clinical trials to learn whether genistein can reduce the risk of cardiovascular disease in marijuana users. They’d also like to extend their studies to include CBD – another cannabinoid in marijuana that does not have the psychoactive effects of THC.”

Stay tuned. I’ll keep you updated.

What Do These Studies Mean For You?

There are several important take home lessons from these and other recent studies:

• Regular cannabis use increases your risk of heart attacks, strokes, atrial fibrillation, and heart failure.

• • Regular cannabis use increases your risk of heart attacks at an early age which can lead to premature death due to cardiovascular complications.

• • The effect of regular cannabis use is equivalent to the risk associated with smoking.

• • The risks appear to be the same for smoking marijuana and use of cannabis edibles.

• • Cannabis use can be particularly deadly for seniors with pre-existing health conditions like diabetes, high blood pressure, and high cholesterol.

We have known about the cardiovascular risks of smoking marijuana for some time, but the last four points are new and are concerning.

• If you are in favor of tighter restrictions on cannabis use, you are probably more concerned about addiction and increased risk of other substance abuse. But the health concerns are additional reasons to restrict cannabis use.

• If you are considering medical or recreational cannabis use, you should weigh the risks carefully. I don’t recommend cannabis use for the same reason I don’t recommend smoking. The health risks are simply not worth the short-term pleasure.

• If you are thinking that cannabis edibles are safer than smoking marijuana, you are probably mistaken.

• If you are a senior with pre-existing health conditions, the risks of cannabis use can be particularly deadly. I am concerned every time I hear that cannabis use is on the rise in seniors.

As for genistein, it would be premature to recommend soy foods containing genistein as an antidote to the cardiovascular effects of cannabis use. We know genistein is safe, but we need clinical studies to prove that it is effective for that purpose.

On the other hand, there is no reason to avoid soy foods containing genistein if you choose to use marijuana or cannabis edibles. Genistein-containing soy protein is an excellent protein source and has many proven health benefits.

The Bottom Line

In this issue of Health Tips From The Professor I discuss studies that show:

• Regular cannabis use increases your risk of heart attacks, strokes, atrial fibrillation, and heart failure.

• • Regular cannabis use increases your risk of heart attacks at an early age which can lead to premature death due to cardiovascular complications.

• • The effect of regular cannabis use is equivalent to the risk associated with smoking.

• • The risks appear to be the same for smoking marijuana and use of cannabis edibles.

• • Cannabis use can be particularly deadly for seniors with pre-existing health conditions like diabetes, high blood pressure, and high cholesterol.

We have known about the cardiovascular risks of smoking marijuana for some time, but the last four points are new and are concerning.

I also share a recent study suggesting a well-known nutrient may help protect against the cardiovascular risks of cannabis use.

For more details about these studies and what they mean for you read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

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About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.

Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 53 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.