Virginia Thornley, M.D., Neurologist, Epileptologist

March 25, 2019

Caffeine (1,3,7-methylxantine) is one of the most commonly ingested stimulants in the world. It is not uncommon for someone to ingest a daily consumption of 200mg of caffeine a day. It is ubiquitously found in soda, coffee, tea, and chocolate. It is the bane of every neurologist who treats migraine and patients with insomnia. It acts as a stimulant and many people use it to counter fatigue induced by lack of sleep. Students consume it to stay up at night for late night studying in order to ace their tests the next day. Millions of people ingest caffeine on a regular basis to get through the full work day.

It has been found in animal models to lower the seizure threshold. At low doses, it reduces the efficacy of anti-epileptic agents. At more than 400mg of caffeine per day, in rodent models it is found to induce seizures. In experimental data, use of caffeine is found to lower the seizure threshold. In mouse models, at lower doses below the seizure-inducing effects, it is found to counter the protective beneficial effects of anti-epileptic agents such as carbamazepine, phenytoin, valproate, and phenobarbital as well as newer agents such as topiramate.  There seems to be no effect of caffeine on newer agents such as tiagabine, oxcarbazepine or lamotrigine. There is clinical data confirming that ingesting high doses of caffeine correlates with greater number of seizures.

Dark chocolate is also found to be a proconvulsant, but little is known about the mechanism of action. Dark chocolate is rich in caffeine. In one mouse study, the effect of high intake of dark chocolate on the susceptibility of hippocampal cells to seizures was examined. Dark cocoa appeared not to affect mood behavior but improved motor coordination.  However, electrophysiologic studies showed enhancement of bursts of epileptogenic potential within the dentate gyrus of the hippocampus. There was a reduction in GABA-alpha receptors suggesting that consumption of dark chocolate may alter the synaptic aspect of epileptogenesis in the temporal lobe.

These findings suggest that high consumption of caffeine especially dark cocoa can increase seizure frequency in animal models and in clinical studies. It seems to act as a proconvulsant and reduces receptors that are necessary for inhibiting seizures.

Reference

1. Chroscinska-Krawzyk, et al, “Caffeine and anticonvulsant potency of anti-epileptic drugs: experimental and clinical data,” Pharmacol. Rep., 2011, 63(1):12-18.
2. Cicvaric, et al, “Sustained consumption of cocoa-based dark chocolate enhances seizure-like events in the mouse hippocampus,” Food Funct., 2018, Mar., 1, 9(3):1532-1544.