Our favorite friend of the website, SCIENCE!, has finally tackled the issue of smoking pot and overindulging in food. A study in this month’s Nature Neuroscience dosed mice with THC to determine what brought about increases in appetite. They determined the answer was two-fold. Here’s the short of it, from Smithsonian Magazine:
THC appears to give us the munchies by convincing our brains that we’re starving.
and
you can smell and taste it more acutely.
But how does it do that? Well, get ready to get science-y. (Long paragraph alert!)
This effect of THC has to do with the underlying reason why the chemical affects the human brain so potently in the first place. Likely produced by the marijuana plant as a self-defense against herbivores who might feel disorientated after eating the plant and avoid it in the future, THC fits into receptors that are part of the brain’s natural endocannabinoid system, which helps to control emotions, memory, pain sensitivity and appetite. Our brains typically produce their own chemicals (called cannabinoids) that fit into these same receptors, so by mimicking their activity, THC can artificially alter the same factors in dramatic ways.
And these cannaboids make the part of your brain tied to your sense of smell go wild.
The scientists began by exposing mice … to banana and almond oils as a test of sensitivity to scent. When they did so, the mice sniffed the oils extensively at first, then stopped showing interest in them, a well-known phenomenon called olfactory habituation. Mice that were dosed with THC, however, kept on sniffing, demonstrating an enhanced sensitivity to the scents.
Basically, THC makes your food smell better and that stimulates your appetite. Additionally, it makes us believe we are hungry even when we aren’t.
…perhaps most interesting is that the new study hints at a compelling metaphor for the way THC manipulates this natural system: it mimics sensations felt when we’re deprived of food. As a final test, the researchers forced some mice to fast for 24 hours, and found that this drove up levels of natural cannabinoids in the olfactory lobe. Not surprisingly, these starved mice showed greater scent sensitivity and ate much more too.
Most intriguing, the genetically engineered mice with olfactory lobes that lacked cannabinoid receptors did not show increased scent sensitivity or appetite even when they were starved. This indicates that both THC and the natural cannabinoids that result from starvation are acting on the same neural pathway to allow us to smell and taste with greater sensitivity, and thus eat more.
And now you know.
/cue G.I. Joe theme.
[Image via Shutterstock]