TUESDAY, May 13 (HealthDay News) -- Smoking marijuana increases the body's production of a protein that raises levels of blood fats associated with heart attack and stroke, government researchers report.
The finding helps explain the increased risk of such cardiovascular problems found in previous studies of marijuana, said Dr. Jean Lud Cadet, chief of the Molecular Neuropsychiatry Research Branch of the National Institute of Drug Abuse. He is lead author of the report, published in the May 13 issue of Molecular Psychiatry.
"We've done a number of clinical papers reporting on marijuana users," Cadet said. "In the past, we have reported cognitive abnormalities, and a paper in 2005 reported vascular [blood vessel] abnormalities."
The latest paper looked at blood levels of a variety of proteins in 18 long-term heavy users of marijuana and 24 volunteers who had never used the drug. It used a new electronic technology that made such protein measurements possible, Cadet said.
"The idea was that there might be marijuana-induced changes in proteins related not only to the vascular problems we were reporting but also to other medical problems marijuana users suffer from," he said.
The analysis showed significantly higher blood levels of apolipoprotein C-III in the marijuana users than in the nonusers. APOC-III is one of a large family of proteins that interact with fats. It delays the breakdown of triglycerides, fats that can accumulate in blood vessels and promote formation of plaques, leading to blockages that can cause heart attacks, strokes and other problems.
"It is a risk factor for cardiovascular disease," Cadet said. "The study suggests that APOC-III might be one of the risk factors contributing to the medical problems that marijuana users suffer from."
In terms of heart disease and stroke, is smoking marijuana more dangerous than smoking tobacco? "It is very difficult on the basis of our study to say," Cadet said, since there was no comparison between marijuana and tobacco smokers.
