Just days after a White House Office of National Drug Control Policy report revealed that teen using marijuana increase their risk of developing a mental disorder by 40 percent, now, another government research reports that smoking marijuana results in changes in the bloodstream that may put chronic users at risk for serious cardiovascular problems such as heart attack and stroke.

Marijuana is one of the world’s most commonly used illegal drugs. There are approximately 300 million users worldwide and 28 million users in the United States alone.

Marijuana comes from a plant called “Cannabis sativa.” The chemical found in this plant that produces the altered states of consciousness is called “delta-9-tetrahydrocannabinol” or “THC.” Whether smoked as a cigarette, or cooked into baked goods like brownies or cookies or brewed like a tea, marijuana use causes: relaxation, reduced coordination, reduced blood pressure, sleepiness, disruption in attention, an altered sense of time and space. In high doses, marijuana can also cause hallucinations, delusions, impaired memory and disorientation.

Now, researchers with the National Institute on Drug Abuse says the THC in the marijuana causes the body to overproduce a protein called ApoC-111, which is linked to high triglycerides (blood fats). High levels of triglycerides can contribute to hardening of the arteries or thickening of the artery walls, raising the risk of stroke, heart attack and heart disease.

For the study, Jean Lud Cadet, MD, with the Molecular Neuropsychiatry Branch at the National Institutes of Health Biomedical Research Council in Baltimore, and colleagues looked at blood samples from 18 regular marijuana users and 24 nonusers.

The researchers found that THC seems to overstimulate marijuana receptors in the liver, leading to overproduction of the protein.

“Chronic marijuana use is not only causing people to get high, it's actually causing long-term adverse effects in patients who use too much of the drug. Chronic marijuana abuse is not so benign,” Cadet said, as quoted by Reuters.

Based on self-reported drug history, the marijuana users in the study smoked 78 to 350 marijuana cigarettes per week.

Marijuana Policy Project, a U.S. group supporting legal sales and regulation of marijuana, disputed the findings, arguing that the people involved in the study were extremely heavy users.

“I think the low end was 78 joints a week. That’s 10 to 11 joints a day. We’re talking about people who are stoned all the time. If you do anything to that level of excess, it might well have some untoward effects, whether it’s marijuana or wine or broccoli,” Bruce Mirken, Marijuana Policy Project spokesperson said.

The study findings were published in the May 13 issue of Molecular psychiatry.