Essential tremor (ET) is a permanent condition marked by involuntary rhythmic movements of the hands (most commonly), head, voice or other body parts. The exact cause is not fully understood, but it is known that the source of ET is malfunctioning brain signals.
Caffeine and ET
There is abundant patient information on the internet that for some ET patients, caffeine makes tremor more pronounced. Authoritative websites like Johns Hopkinsi and Mayo Clinicii note that caffeine may make tremors worse, and advise ET patients to avoid it. Patient discussion boards such as the Essential Tremor Support Group page at DailyStrength.orgiii contain patient posts about avoiding caffeine. With such a preponderance of physician and patient opinion, let’s see what research tells us.
Research on caffeine and ET
Two studies shed some light on the effect of caffeine and essential tremors.
1. A 30-year old study compared tremor patients (both ET and Parkinson’s disease) with a non-tremor (normal) control group. Based on questionnaires before taking a single oral dose of caffeine (325 mg), eight percent of ET patients and six percent of PD patients thought that coffee worsened their tremor. These numbers compare to only two percent of the control group who thought that coffee made their hands shaky. Once the participants had consumed the dose of caffeine, they were followed at 1, 2 and 3 hours after ingestion. The study team found that caffeine “only infrequently” causes tremor in normal people, and it does not make either ET tremors or PD tremors worse.
2. A contemporary (2017) study likewise compared two groups, ET patients and matched non-tremor controls. In this questionnaire-based research, the intake of coffee and tea of all participants was recorded for analysis, and for correlating with each person’s tremor score and the duration of their condition. The authors found no correlation between caffeine consumption and the severity or duration of ET. As they summed it up, “Caffeine consumption was not associated with risk of ET in our study population.”
The “truth” lies somewhere between
If these two studies, 30 years apart, suggest that there’s no link between caffeine and the frequency or severity of ET, what does this say about the experience of individual patients whose tremors are aggravated by coffee or tea? In all likelihood, the “truth” may lie somewhere between the research and the patient world. Since fatigue is a recognized factor in making tremors worse, it’s possible that caffeine itself is not the tremor-causing culprit, but it may result in patients feeling more wakeful (and getting less sleep). Insufficient sleep can make a LOT of things worse!
Keep a journal
If you have been diagnosed with ET, you may have been encouraged by your neurologist to keep a journal or log about your tremors. This is a good way to track how often your tremors occur, and what is going on before and during the more severe incidents. Your journal might include things like the time of day, what you ate/drank before tremors occurred (or got worse), your emotional state, any unusual event that upset or worried you, etc.
The most important thing is to trust your own experience. No matter what a published paper says, if you notice that your tremors become more vigorous after coffee, tea, carbonated beverages with caffeine, etc. then it’s up to you to decide if it’s worth drinking them. For optimum quality of life when living with ET, common sense may be your best advisor.