The Harms of Tea and Coffee to the Body

While studying this year, I came across content in two of our major textbooks stating that caffeine is harmful to the body: one is our Physiology textbook, the other our Biochemistry textbook. Both are important foundational courses in medicine; that such content appears in the textbooks shows that caffeine's harm to the body is accepted by the medical community.

Both tea and coffee contain caffeine: coffee beans contain 1.2%–2.7% caffeine, and tea leaves 2%–3%. Both are common drinks in daily life, and many articles praise their benefits, but few describe their harms.

I used to drink tea and coffee. My reaction to tea is quite strong; every time I drink it my stomach feels uncomfortable. When I first started coffee I did not react as strongly as to tea, but over time I came to feel its harms. Caffeine is also somewhat addictive; although breaking a caffeine habit is not difficult, addiction means people keep suffering its harms without realizing it.

Caffeine harms the body in many ways, damaging the nervous, cardiovascular, and digestive systems. Long-term drinkers of coffee and tea may develop: stomach pain, heartburn, acid regurgitation, constipation, diarrhea, irritability, easy fatigue, memory decline, insomnia, weight loss, limb numbness, palpitations, arrhythmia, tachycardia, and hand tremor. Those who already have nervous-system disorders may find long-term coffee and tea worsens emotional instability. Caffeine also causes calcium loss, leading to osteoporosis and other problems. Excess caffeine in adolescents may interfere with nervous-system development; excess in pregnant women can cause miscarriage. In hypertensive patients, long-term caffeine intake makes blood pressure harder to control.

Caffeine's harms are easily overlooked, because so many promotional articles stress the benefits of coffee and tea and selectively ignore the harms. So when people develop the above symptoms, they do not first think of caffeine; they assume they have some disease. They finally go to hospital for a pile of tests, yet still cannot find the cause.

China's medical textbooks encourage people to give up alcohol and long-term consumption of caffeinated drinks, because a large body of clinical statistics shows that long-term caffeine intake is very harmful. People with arrhythmia, stomach problems, or neurasthenia should especially stay away from caffeine.