Wake 'n' bake - what caffeine and cannabis have in common

Coffee puts the neurotransmitters of the endocannabinoid system in low gear, while cannabis ramps them up.
Coffee and marijuana work on some of the same neurotransmitter systems in the brain - coffee turns them up, and pot turns them down. (Laia Solanellas, cc-by-sa-2.0 - coffee cup and minto - hand)
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The coffee experiment

A recent study of the health effects of drinking coffee by Canadian researcher Dr. Marilyn Cornelis, an assistant professor of preventative medicine at Northwestern University in Chicago, has come to a couple of significant conclusions. 

One is that coffee affects the metabolism of steroids; and the other is that it has the opposite effect on the neurotransmitters of the endocannabinoid system that smoking pot does. 

In Dr. Cornelis's experiment, 47 coffee drinkers did not have coffee for one month, then had four cups a day in the second month, then eight cups a day in the third month. The team looked at more than 800 metabolites in blood samples after each stage of the study.    

Coffee and pot

They found neurotransmitters related to the body's endocannabinoid system, decreased after drinking four or eight cups of coffee per day.

The same neurotransmitters increase after smoking marijuana. Because endocannabinoid pathways are linked to eating behaviours, the increase in neurotransmitters from smoking pot may explain the increase in appetite, known as the munchies. 

Coffee and health

They also found that metabolites associated with the excretion of steroids went up with coffee consumption. This suggests a connection between drinking coffee and the elimination of steroid compounds from the body. 

Because the steroid pathway is a focus for diseases including cancer, it may be that coffee consumption may have an effect on such diseases as well.

Dr Cornelis is continuing her research on coffee, and is interested in the effects of coffee and cannabis together.