The stereotype of pot smokers as people who wolf down Cheetos, brownies, and whatever else happens to be in the room isn’t entirely false. One study even showed that marijuana smokers eat up to 600 extra calories per day compared to their more sober counterparts.
But this isn’t a story warning about the dangers of smoking weed. No, this is where we get to tell you that the 17.4 million marijuana smokers in the U.S. tend to be skinnier and have lower blood sugar. This is all according to a study published in The American Journal of Medicine, where researchers from Harvard, the University of Nebraska, and Beth Israel Deaconess Medical Center, studied marijuana statistics from 4,657 patients who had completed the National Health and Nutrition Survey between 2005 and 2010.
Studies in the past have already shown that marijuana is linked to lower body weight. But the lower insulin resistance bit is new—and could mean that doctors one day prescribe cannabis for diabetes.
Among the study participants, 12.2% currently used marijuana at the time of the study and 47.7% had used it at least once before (but not for 30 days). After adjusting for age and sex, the researchers found current marijuana use is linked to lower waist circumference, fasting insulin, glucose, HOMA-IR (a measure of insulin resistance) and BMI—as well as higher HDL cholesterol, which fights heart disease.
"It is possible that the inverse association in fasting insulin levels and insulin resistance seen among current marijuana users could be in part due to changes in usage patterns among those with a diagnosis of diabetes (i.e., those with diabetes may have been told to cease smoking). However, after we excluded those subjects with a diagnosis of diabetes mellitus, the associations between marijuana use and insulin levels, HOMA-IR, waist circumference, and HDL-C were similar and remained statistically significant," explained Elizabeth Penner, MD, MPH, an author of the study, in a press release.
Why is this happening? The researchers aren’t quite sure, but they speculate it might have something to do with cannabis’s relationship to adiponectin, a protein involved in regulating glucose and lipid metabolism. They write:
Although not completely elucidated, the mechanisms by which cannabinoids affect peripheral metabolism via these receptors have been studied extensively; the cannabinoid type 1 receptor antagonist, rimonabant, was found to improve insulin sensitivity in wild-type mice, but not in adiponectin knockout mice, suggesting that adiponectin at least partially mediates the improvement in insulin sensitivity; adiponectin has been reported to improve insulin sensitivity. This rimonabant-induced improvement in insulin resistance has been confirmed in human studies.
They point out that one of the body’s cannabinoid receptors (activated by chemical compounds found in marjiuana) may be "central in the metabolic processes leading to obesity." Nobody quite knows why. While we wait for scientists to figure it out, you can feel a little less bad about smoking marijuana. It’s all in the name of blood sugar control.