THE PHARMACOLOGY OF COFFEE

It's one of the most widely used stimulants on earth, and contains a number of interesting psychoactive compounds, this is an in depth review of what sets coffee apart from every other source of caffeine

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To understand how coffee works in the brain, first you need to understand caffeine

Caffeine belongs to a class of compounds called xanthines, which act as antagonists at the adenosine receptor

Adenosine is an nucleotide used in cell signalling

It is primarily anti-inflammatory, but also stimulates appetite, and helps aid in sleep and reducing anxiety by blocking calcium channels (the same mechanism as GABA)

It's one of the primary inhibitory neurotransmitters

Caffeine promotes wakefulness by blocking the action of adenosine, this allows dopamine, norepinephrine, and glutamate (all stimulating NTs) to reach higher concentrations than they would normally

It has also been shown to block GABA release, which further adds to this effect

The increase of dopamine especially is responsible for the mild addictiveness of caffeine

It is actually estimated that ~90% of adults and children worldwide use caffeine regularly, and many of them are physically dependent

Aside from it's effect on adenosine, caffeine also inhibits the enzyme PDE, which results in decreased inflammation and immune system function

It also inhibits acetylcholinesterase, increasing acetylcholine levels which improves memory and cognition

Withdrawal from caffeine often causes headaches and/or fatigue

The fatigue is caused by excess adenosine buildup and lowered dopamine production after longterm use, adenosine dilates blood vessels which can trigger headaches in some people as well

Interestingly enough though, coffee contains other psychoactive compounds besides caffeine

It also contains the beta-carbolines harmane and norharmane, which mildly inhibit MAO, the enzyme which breaks down serotonin, dopamine, and norepinephrine

Beta-carbolines are produced when coffee is roasted, and are also found in tobacco and in trace amounts in many processed foods

Much more potent beta-carbolines are the primary active compounds in ayahuasca

While caffeine inhibits the release of serotonin, harmane and norharmane increase it's concentration

This is part of the reason why coffee has a more positive impact on mood and more stimulating properties than other caffeine sources like green tea

Coffee also contains 4-caffeoylquinide, a compound which acts as an antagonist at the mu opiate receptor (the anti-overdose drug Narcan has the same activity)

Interestingly, in animal studies it was actually potent enough to block the effects of morphine in mice

I personally believe this compound is the main reason why many people get worse anxiety from coffee than caffeine on it's own, since blocking the ORs also blocks GABA

Since opiates receptors are also found in and regulate the gut, it's also why coffee speeds up digestion

Overall coffee has many benefits, it improves memory and concentration, may reduce inflammation, and has even been shown to improve blood brain barrier function which may help prevent alzheimers

However coffee can also cause dependence and dysregulate many processes in the brain

Every substances has both positive and negative effects, I believe we must all weigh the evidence for both and decide for ourselves what we put in our bodies

If you have any questions feel free to DM or reply

Thanks for reading