“Why, this Satan’s drink is so delicious that it would be a pity to let the infidels have exclusive of it. We shall fool Satan by baptizing it and making it a truly Christian beverage.” — Pope Clement VIII (d.1605)

Like Homo sapiens, coffee has its origins in East Africa. Coffee still grows wild in certain regions of Ethiopia. And the Ethiopians have a delightful story about the origin of coffee drinking.

Apparently, a shepherd was out with his goats one day and fell asleep. When the shepherd went to gather his goats, he noted that some of the goats were quite frisky and energetic. These same goats were eating a red cherry-like fruit. According to the legend, the shepherd decided to try the red fruit and also felt more alert and energetic, and so human’s love of coffee began.

Coffee made its way from East Africa across the Red Sea into the Mocha region of Yemen and from there into the Muslim world. Westerners who travelled to Istanbul and other Muslim areas provided the first reports of the new black drink to Europe.

Another story about coffee is that as the Ottoman Turks were retreating from the gates of Vienna, bags of coffee beans were left by the fleeing troops. Initially, the Europeans did not know what to do with the beans and began to destroy them. But one European soldier who had been in Turkey said that he knew what to do with them, and this enterprising young man opened the first coffee shop in Europe. The Viennese were the first to add milk to coffee. (For those interested in reading more of the fascinating history of coffee, I recommend two books: “Uncommon Grounds,” by Mark Pendergrast, and “The Devil’s Cup,” by Stewart Lee Allen.)

Although coffee contains a myriad of beneficial bioactive chemical compounds, it is caffeine that is the one that we are most familiar with. It is a compound that stimulates the central nervous system and gives us that feeling of energy, alertness and concentration that we associate with coffee. However, caffeine can become toxic if we consume more than 300 to 400 mg per day.

People who ingest more than this amount may exhibit tremors, insomnia, nervousness and anxiousness. Withdrawal symptoms can also occur when heavy caffeine users abruptly stop using caffeine. The most common withdrawal symptom is headache.

The website caffeineinformer.com has a list of the caffeine content of several popular caffeinated beverages and products. For example, a Venti Blonde Roast from Starbucks has about 475 mg of caffeine; three tablets of GNC amp (pre-Post) supplement have 400 mg of caffeine; and an 8-oz. cup of Lipton Green Tea has 16.4 mg of caffeine.

In October, the British Medical Journal published a comprehensive review of many studies of health and coffee. The authors found that coffee was “more often associated with benefit rather than harm for a range of health outcomes…” There was noted to be a reduction in all-cause mortality, cardiovascular mortality and cardiovascular disease.

This review also found that coffee drinkers had a lower risk of prostate cancer, endometrial cancer, melanoma, adult leukemia and liver cancer. There was also noted to be a reduced risk of gallstones, gout and Type II diabetes.

Harmful effects of coffee were noted in pregnancy. Coffee consumption was associated with lower birth weights, increased pregnancy loss and possibly increased risk of childhood leukemia. There also was a slight association between high coffee consumption and the risk of fractures in women.

So, what does this all mean for you?

Most of the benefits occurred in people who drank three to four cups of coffee per day as long as the caffeine amount did not exceed the 300 to 400 mg level described above. I recommend checking out the caffeineinformer.com website to see how much caffeine your favorite beverage has.

In my mind, it is not clear whether the benefits stem from the bioflavonoids and other active ingredients in coffee, the caffeine or the interaction of the caffeine with the bioactive substances in coffee.

So, as you sit in your favorite café, in your kitchen or at work drinking this delightful beverage with such a rich history that also has health benefits, take a minute to thank the Ethiopian shepherd and his frisky goats for their discovery.

Dr. Alan Jackson is a cardiologist and chief medical officer at Roseland Community Hospital and clinical assistant professor of medicine at the University of Illinois Chicago. He also is a member of the Sun-Times board of directors.