Mr. A has suffered from anxiety for many years. After receiving psychiatric treatment, his condition improved slightly, but his irritability, hand tremors, palpitations, and insomnia were still not completely eliminated. A few months ago, he gradually reduced his caffeine intake and his condition improved significantly.
One of the effects of caffeine entering the brain is to hinder the function of the neurotransmitter “adenosine” in promoting sleep, resulting in reduced drowsiness. At the same time, caffeine also stimulates the activity of the sympathetic nervous system, putting the body and mind into a state of tension. Excessive caffeine intake can cause insomnia, irritability, anxiety, increased heart rate and blood pressure, nausea, and headaches.
However, why do many people not feel any discomfort even if they drink more than one cup of coffee a day? According to the U.S. Food and Drug Administration, the safe daily caffeine intake limit for adults is 400 mg. An eight-ounce cup of coffee contains approximately 100 milligrams of caffeine. But this does not mean that every adult can tolerate 4 cups of coffee a day. How quickly everyone metabolizes caffeine varies greatly. Studies have found that the time required to reduce blood caffeine levels by half ranges from 1.5 to 9.5 hours. In addition, everyone’s body sensitivity to caffeine is very different.
In the past, Mr. A would always drink one or two cups of coffee to refresh himself after lunch as a precaution to avoid drowsiness in meetings. Around 4 o’clock, he would drink another cup of coffee. The drowsiness would be indeed reduced, but the tiredness and agitation remained. To solve these new issues, he sometimes would take sedatives. The palpitations were slightly reduced, but the medicine made him sleepy. He would have to drink coffee again to refresh himself. At night he would still be too agitated to sleep, so he had to take sleeping pills. However, the sleeping pills made him still sleepy after waking up, thus he had to drink even more coffee in the morning, creating a vicious cycle. Now, Mr. A only enjoys a small cup of coffee in the morning. After lunch and tea time, he spends 15 minutes walking outside. Mr. A discovered that natural light can both refresh and calm the mind, making it the best spiritual supplement.
Written by: Dr. William Chui
Originally posted on: HKEJ Health
Translated by: Cheuk Long Chan
