Smoking marijuana and tobacco linked to elevated levels of toxic chemicals

Smoking marijuana or tobacco can lead to rising levels of toxic chemicals in the blood and urine, according to a new study published in EClinicalMedicine. Tobacco smoke is also associated with a heightened risk of cardiovascular disease.

A group of scientists from the CDC and the Dana-Farber Cancer Institute in Boston collaborated on the research, using data from 245 patients.

“Marijuana use is on the rise in the United States with a growing number of states legalizing it for medical and nonmedical purposes—including five additional states in the 2020 election,” senior author Dana Gabuzda, MD, of the Dana-Farber Cancer Institute, said in a statement. “The increase has renewed concerns about the potential health effects of marijuana smoke, which is known to contain some of the same toxic combustion products found in tobacco smoke.”

All patients had previously participated in U.S.-based HIV research. That specific group was used because of their high rates of tobacco and marijuana use.

Participants were all over the age of 40, and 76% were HIV-positive. While 18% of participants only smoked marijuana, 20% only smoked tobacco and another 24% smoked both.

Overall, the authors noted, participants who only reported smoking marijuana had higher levels of numerous toxic chemicals in their blood and urine than those who did not smoke at all. Participants who smoked tobacco had even higher levels of those same chemicals.

In addition, smoking tobacco was associated with elevated levels of acrolein metabolites—and that increase was linked to a greater risk of a cardiovascular disease.

“Our findings suggest that high acrolein levels may be used to identify patients with increased cardiovascular risk, and that reducing acrolein exposure from tobacco smoking and other sources could be a strategy for reducing risk,” Gabuzda added.

The full study can be read here.