Who doesn’t love coffee? Caffeine is the #1 psychoactive drug in the world! But is it OK to drink Coffee after a concussion? Well yes, it is. It may even help. Is it OK to drink Coffee with post-concussion syndrome, (PCS)? Not so much.
What Caffeine does to the Brain
Caffeine makes you alert by blocking receptors for Adenosine, a neurotransmitter that makes you sleepy. But here’s the thing, those same receptors have a lot to do with brain inflammation. Brain inflammation or neuroinflammation is responsible for many of the symptoms of concussion and PCS. Adenosine receptors can either increase or decrease neuroinflammation depending on how much glutamate, (a neurotransmitter that causes inflammation) is circulating in the brain[1].
If there is a lot of glutamate, like soon after a concussion, stimulating Adenosine receptors makes even more inflammation. Blocking those receptors with caffeine will lessen that initial response and the severity of symptoms. If glutamate levels have gone down like it does later in post-concussion syndrome, stimulating Adenosine receptors is anti-inflammatory. So…when you block the receptors with caffeine in the chronic post-concussion syndrome it lessens their anti-inflammatory action. Not so good.
Just to make it even more complicated, caffeine also stimulates glutamate release in certain areas of the brain[2]. So if you drink coffee or tea or Coke or Red Bull when newly concussed, you may be blocking one inflammatory pathway, but increasing another. If you have PCS you are both blocking the anti-inflammatory action of the Adenosine receptors and increasing inflammation from glutamate.
4 more reasons not to drink coffee with Post-concussion Syndrome
Caffeine also makes us more alert by increasing the release of a hormone that tells the Adrenal gland to release Cortisol. Cortisol increases blood sugar and that signals the release of insulin to move the sugar from your blood into your cells for energy. Bursts or residual Cortisol, sugar and insulin in the blood can all contribute to neuroinflammation.
Caffeine is addictive because when you block Adenosine receptors, the body makes more. You need more to get the same effect. When you drink less or stop, you go through withdraws. Those withdraws have some of the same symptoms as concussion or PCS. You may get irritable, tense, uneasiness, dissatisfaction with life, sleepy, nausea, vomiting, nervousness, anxiety, muscle tension, or muscle pains. Regular coffee drinkers can get muscle tension and anxiety after just 3 hours without coffee[3]. We think of having a nice relaxing cup of coffee, but it may just be relaxing because it’s withdraw relief.
Caffeine also affects circulation. The brain needs lots of oxygen to function and even more to heal. Altering blood flow to the brain dysregulates the oxygen supply. This is also why you may get severe headaches when going through withdraw.
If that wasn’t enough, caffeine also impacts dopamine receptors and decreases GABA production, two other neurotransmitters. This increases dopamine related brain activity which is related to the kind of rage that is sometimes experienced by concussion survivors.
To Bean or not to Bean
So is it ok to drink coffee after a concussion? If you were a regular coffee drinker before being concussed and kept drinking for a few weeks post injury, you may have actually lessened the severity of your symptoms. But, what is good for you one day might be bad for you the next. Once that initial neuroinflammatory surge started to quiet down, caffeine may be one of the reasons it just didn’t go away.
Considering that quitting caffeine cold turkey is a rather unpleasant shock to the brain, not to mention your friends and family, the best thing to do may be to gradually taper down. A week or two after injury switch to half-caf, then quarter-caf and drink less until you are no longer trying to regulate your energy level and emotions with a hot beverage.
Contributed by Dr. Jonathan Smith, DC, CSCP
[1] Dai, Shuang-Shuang, Yuan-Guo Zhou, Wei Li, Jian-Hong An, Ping Li, Nan Yang, Xing-Yun Chen et al. “Local glutamate level dictates adenosine A2A receptor regulation of neuroinflammation and traumatic brain injury.” Journal of Neuroscience 30, no. 16 (2010): 5802-5810.
[2] Alasmari, Fawaz. “Caffeine induces neurobehavioral effects through modulating neurotransmitters.” Saudi Pharmaceutical Journal 28, no. 4 (2020): 445-451.
[3] White BC, Lincoln CA, Pearce NW, Reeb R, Vaida C. Anxiety and muscle tension as consequences of caffeine withdrawal. Science. 1980 Sep 26;209(4464):1547-8. DOI: 10.1126/science.7433978