For most of us, coffee is more than a beverage. But how much do we really know about it, other than it is a pleasurable social event?
Kaldi’s coffee
The most popular story of the discovery of coffee centres around a young goat herder, named Kaldi, in the Ethiopian province of Kaffa around the late 6th century.
Legend has it that he noticed a strange restlessness in his flock after they had eaten the berries and leaves of an unknown plant. Monks, from a nearby monastery, heard of this phenomenon and after various trials discovered that by roasting, grinding and infusing (in water) the seeds of this plant, a unique beverage could be obtained that helped keep them awake, during long hours of prayer.
Word of this special drink quickly spread and it was soon drunk in houses in the far away holy cities of Mecca and Medina. Propagation of the coffee bean began in Yemen and was well-established by the 15th century.
Health effects
The health effects come from caffeine – one of a group of chemical compounds, called methylxanthines, which occur naturally in over 60 species of plants, including coffee beans, tea leaves, cocoa beans and cola nuts.
A surprising fact about coffee is that it’s a very good source of antioxidants, is good for concentration and even athletic performance. Although, those competing in sport need to be aware that taking in more than 500mg per day could result in exceeding the limit allowed, resulting in being banned from competing.
The average intake of caffeine per day is 100 to 300mg, which is equivalent to two to three caffeine containing beverages, such as coffee. The current health recommendation is not to exceed four cups per day.
Side effects of caffeine overdose include sweating, increased heart rate, trembling, anxiety, loss of appetite, upset stomach, headaches, dizziness, insomnia, increased urinary output which could cause dehydration, and decreased perception of fatigue.
However, the responses to caffeine doses are individualised and people will never experience the above symptoms even with high doses of caffeine.
Average caffeine content in a standard cup |
|
Roast and ground coffee (dependent on strength of brew) |
80-90mg |
Instant coffee |
65-85mg |
Decaffeinated coffee (roast, ground or instant) |
2-5mg |
Tea (dependent on brewing time) |
40-70mg |
Green tea |
30-60mg |
Hot chocolate |
2-8mg |
Chocolate milk (e.g. Nesquik) |
100mg |
Hot cocoa |
2-8mg |
MEET OUR EXPERT – Berna Harmse
Berna Harmse is a private practicing dietician in Cape Town, she holds a MSc in Dietetics and has a special interest in oncology nutrition. She is also an external lecturer at Stellenbosch University Division of Human Nutrition.