by Pamela Powers Hannley
A new research study published today in the American Journal of Medicine found that current marijuana users had significantly lower fasting insulin, were less likely to be insulin resistant (a pre-diabetic state), and were more likely to have high HDL (good cholesterol). (Read the study here.)
Marijuana (Cannabis sativa) has been used for centuries to relieve pain, improve mood, and increase appetite. Outlawed in the United States in 1937 and further restricted under the Controlled Substances Act by the Nixon Administration, marijuana use has continued to increase. There are an estimated 17.4 million current users of marijuana in the United States. Approximately 4.6 million Americans smoke marijuana daily or almost daily. With the recent legalization of recreational marijuana in Washington and Colorado and the legalization of medical marijuana in 19 states and the District of Columbia, US public opinion has moved toward less stringent laws.
In an accompanying editorial, Dr. Joseph S. Alpert of the University of Arizona College of Medicine calls on the federal government to open the doors of medical research to marijuana, allowing free investigation of the drug. Study details after the jump.
This new study about insulin control and pre-diabetes was conducted by a multicenter research team which analyzed data from the National Health and Nutrition Survey (NHANES) between 2005 and 2010. They analyzed data from 4,657 patients who completed a drug use questionnaire. Of these respondents, 579 were current marijuana users, 1,975 had used marijuana in the past but were not current users, and 2,103 had never inhaled or ingested marijuana. Fasting insulin and glucose were measured via blood samples, and insulin resistance was calculated.
Participants who reported using marijuana in the past month had lower levels of fasting insulin and insulin resistance and higher levels of high-density lipoprotein cholesterol (HDL-C). Large waist circumference also is linked to diabetes risk, and this study also sowed significant associations between marijuana use and smaller waist circumferences.
These associations were weaker among those who reported using marijuana at least once, but not in the past thirty days, suggesting that the impact of marijuana use on insulin and insulin resistance exists during periods of recent use. Current users had 16% lower fasting insulin levels than participants who reported never having used marijuana in their lifetimes.
“Previous epidemiologic studies have found lower prevalence rates of obesity and diabetes mellitus in marijuana users compared to people who have never used marijuana, suggesting a relationship between cannabinoids and peripheral metabolic processes, but ours is the first study to investigate the relationship between marijuana use and fasting insulin, glucose, and insulin resistance,” says lead investigator Murray A. Mittleman, MD, DrPH, of the Cardiovascular Epidemiology Research Unit at the Beth Israel Deaconess Medical Center, Boston.
Although people who smoke marijuana have higher average caloric intake levels than non-users, marijuana use has been associated with lower body-mass index (BMI) in two previous surveys. “The mechanisms underlying this paradox have not been determined and the impact of regular marijuana use on insulin resistance and cardiometabolic risk factors remains unknown,” says coauthor Hannah Buettner.
The investigators acknowledge that data on marijuana use were self-reported and may be subject to underestimation or denial of illicit drug use. However, they point out, underestimation of drug use would likely yield results biased toward observing no association.
“We desperately need a great deal more basic and clinical research into the short- and long-term effects of marijuana in a variety of clinical settings such as cancer, diabetes, and frailty of the elderly,” said Editor-in-Chief Joseph S. Alpert, MD, Professor of Medicine at the University of Arizona College of Medicine. "I would like to call on the NIH and the DEA to collaborate in developing policies to implement solid scientific investigations that would lead to information assisting physicians in the proper use and prescription of THC in its synthetic or herbal form.”
This is the second major study released this week about the medical benefits of marijuana. On Monday, a study showing decreased bladder cancer risk among marijuana smokers compared to cigarette smokers:
Marijuana Linked To Lower Bladder Cancer Risk, Study Says
I think it is high time [pun intended] that the US government end its polilically motivated, schizophrenic policies toward marijuana. States should stop putting up economic roadblocks to medical marijuana clinics. (What other legal industries have been victimized in this way?) And the Obama Administration should stop the crackdowns on clinics and open up the doors to research, which were closed by President Nixon.