The heart of the matter: Cardiac studies present mixed results

For most of the past year, COVID-19 reigned as the world’s main health concern. Yet even then, as now, the No. 1 cause of death around the world involved the human heart.

That’s according to the World Health Organization, which says the “world’s biggest killer is ischemic heart disease” – defined as heart problems caused by narrowed heart arteries.

“Since 2000,” the WHO reports, “the largest increase in deaths has been for this disease, rising by more than 2 million to 8.9 million deaths in 2019.”

Here’s the bad news for those who smoke cannabis: Not only can doing so cause an undue strain on your heart, it’s also particularly harmful for those with an established history of heart disease.

A 2017 story in Harvard Health Publishing, a newsletter published by Harvard Medical School, cites research that indicates that cannabinoid effects include “raising resting heart rate, dilating blood vessels and making the heart pump faster.”

This may not mean much to those with otherwise healthy hearts, the story asserts, but “it should be a red flag for anyone with a history of heart disease.”

Research conducted by the American Heart Association agrees with the WHO assessment, especially when it comes both to the methods of delivery (smoking or vaping as opposed to edibles, tinctures, etc.) and to the presence of THC.

“Many consumers and health care professionals don’t realize that cannabis smoke contains components similar to tobacco smoke,” said Robert L. Page II, chair of the group that authored the AHA statement, which was released in August 2020.

Furthermore, the AHA report linked “THC-containing products” with such heart problems as “vascular inflammation and oxidative stress.”

While emphasizing that cannabis may have benefits – among them relief from muscle stiffness associated with multiple sclerosis and neuropathic pain felt by those afflicted by Type 2 diabetes – the AHA report was clear in its evaluation of cannabis and the heart.

“Cannabis,” the report stated, “does not appear to have any well-documented benefits for the prevention or treatment of cardiovascular diseases.”

Yet the same report indicated that use of CBD – cannabis products with little or no THC – can actually be heart-healthy in a number of ways, from reducing heart rate and lowering blood pressure to lessening inflammation and increasing the ability for arteries to open.

More good news regarding CBDs and heart health was announced during the summer of 2019 at a symposium held by the International Cannabinoid Research Society. The news involved a study that examined “the acute and chronic effects of cannabinoid on cardiovascular function.”

Conducted at England’s University of Nottingham, the study indicated that CBDs were capable of lowering blood pressure during stress.

While there were some issues involving tolerance to “chronic CBD administration” that concerned the researchers, spokeswoman Saoirse E. O’Sullivan lauded the “positive effect in vascular function” that the CBDs achieved. Such an effect, she added, “warrants further investigation in relevant patient populations.”

Further investigation, in fact, is the ongoing rallying cry for most cannabis researchers, including the chair of the AHA study mentioned above.

“We urgently need carefully designed, prospective short- and long-term studies regarding cannabis use and cardiovascular safety as it becomes increasingly available and more widely used,” Page said. “The public needs fact-based, valid scientific information about cannabis’ effect on the heart and blood vessels.”