by Dr. Ijeoma J. Dozie MBBS, FMCFM
As a new employee at my current job, I was pleasantly surprised to discover that everyone was entitled to a sachet of tea/coffee/hot chocolate and a snack at lunchtime. As a tea/coffee lover myself and coming from my previous job where the coffee-and-hot-chocolate-dispenser was a mainstay, the continuity felt good. So, I fell into the routine of making a cup of coffee with a coffee-mix sachet daily and all was well. This was till one fateful day, I went to get my coffee-mix sachet and was instead offered chocolate powder and milk. I, of course, wanted to know why and was told that staff or two had suggested discontinuing coffee because they had heard it was carcinogenic. Carcinogenic? Coffee? Hmm. I understood why this could be a contentious issue. I remembered attending a workshop at Lagos University Teaching Hospital (LUTH), Idi – Araba, on the Health Benefits of Coffee, four years earlier; I also recalled many recent studies stating the numerous positive attributes of coffee and a few stating its negative effects. It thus became imperative to research further and educate us all.
What is Coffee and How Did It Become Nutritious?
Coffee is thought to have been first discovered by Kaldi, a goat – herder in ninth-century Ethiopia, when he saw his goats getting excited after eating some berries from a tree. 1 He reported to the abbot at the local monastery who decided to dry (by roasting) and boil the berries to make a beverage. This drink with its unmistakable aroma, kept him and his fellow monks awake for hours, enhancing their ability to stay up longer to pray. Word soon spread about this wonder drink to the Arabian Peninsula and beyond and by the 16th century, coffee was the beverage of choice in Persia, Egypt, Syria and Turkey. From the Middle East, its popularity spread through the Balkans, Italy and throughout Europe, east to Indonesia and then west to the Americas. 1 Many other accounts of the origins of coffee exist but that is not our interest here.
I recall coffee being the beverage of choice for students who wanted to burn the proverbial midnight oil or read till daybreak (TDB). I also remember accounts of students who had, a night before their exams, taken very concentrated forms of coffee (some had even chewed the grains raw), and of how they ended up unable to focus, highly excitable and of course unable to write their exams. Coffee was also found to exacerbate Acid reflux and Peptic ulcer disease symptoms and was observed to transiently but temporarily elevate the blood pressure. Thus, promoting the wariness surrounding coffee and its effects.
This wariness had begun way back in history with coffee being considered sinful (haraam) and banned in Mecca in the 16th century. 1 It was called ‘the devil’s cup’ among Catholics in Europe at about that time too and with the establishment of coffeehouses called ‘schools of the wise’ where people went to get the latest news, exchange ideas and discuss politics, a social revolution was forged which made the government of the time uncomfortable leading to prohibitions and bad press. 1 However, many of these views have since changed.
In recent times a substance called Acrylamide found in coffee was said to be associated with cancer.
Acrylamide and Cancer
Acrylamide is a chemical that could be found in coffee, French fries, toasted bread, crackers, cereals and cigarettes. 2 It is formed during the high- heat cooking, roasting or frying involved in the preparation of these aforementioned products. Since its initial classification as a “probable carcinogen” by the International Agency for Research on Cancer (IARC) – the arm of the World Health Organisation (WHO) responsible for assessing whether certain substance cause cancer or not, it had had lots of controversies surrounding it despite the fact that amounts found in coffee were quite small compared to amounts found to cause cancer in animals. 2,3,4 In keeping with this, in 2011 and 2014, two large studies summarized that no association existed between dietary acrylamide and risk of several cancers. 2 Thereafter, in 2016, the IARC, based on current evidence could not conclude that drinking coffee was carcinogenic. 2
Now For The Good News
Coffee remains one of the most enjoyed, most popular and most researched drink around the world with caffeine (also found in chocolate, cocoa drinks, carbonated cola drinks and tea) being its most studied component.
It is a bean seed and like all seeds, coffee is loaded with antioxidants and many protective compounds that help the human body fight free radicals, which are chemicals that damage body cells and can lead to disease and illness.
Some short term health benefits of coffee include:
- Increased mental alertness; improvements in vigilance and reaction time; and improved athletic performance.3
Some possible long term benefits of coffee include:
- Lowered risk of several types of cancers, including head and neck, liver, colorectal and breast cancers, according to IARC.2
- Protection against liver cancer and colorectal cancers according to a recent meta-analysis. 3
- Reduced risk of Parkinson’s disease, Alzheimer’s disease, alcoholic cirrhosis, and gout. 3
- A lower risk of type 2 diabetes mellitus (DM). 3 However, coffee raises blood sugar levels transiently in people who already have DM and in such cases, switching to decaffeinated coffee which has fewer effects on blood sugar is recommended. 2,3
- Reduction in the overall risk of mortality. 4, 5 This means that coffee drinkers were found to live longer, irrespective of the amount, caffeine content or lack and/or presence of genetic polymorphism (rate of caffeine metabolism). This was according to a prospective cohort study of half a million people carried out in the United Kingdom spanning 10 years between 2006 and 2016. 5 This study also found that other non-caffeine components of coffee contributed to this longevity effect. 5
- Protection against endometrial, colon, prostate and liver cancers according to a 2010 study done by the University of California, Los Angeles. 2
- Protection against heart diseases due to a reduction in the build-up of calcium in the blood vessels that bring blood to the heart.2
The Acceptable Dose of Coffee (Caffeine) In Children and Adults
Caffeine, the most popular component of coffee, is the most consumed stimulant in the world; usually in form of coffee, tea, soft drinks, chocolate and energy drinks. Energy drinks can contain more than 500 mg of caffeine per serving, whereas a cup of coffee has 75 to 150 mg of caffeine and a typical cola has about 35mg. 6
In children below 18 years, consuming amounts of caffeine greater than 2.5mg/kg per day may not be considered safe. 3 So extra care must be taken in them to restrict unnecessary sources.
In adults, on the other hand, taking above 300mg to 400mg per day or more than three (3) to five (5) cups of coffee daily is likely to have negative effects like irritability, disruption of sleep pattern and worsening bone calcium loss (osteoporosis) in postmenopausal women. 2,3 Fortunately, minimising the number of cups taken a day and taking calcium tablets, in postmenopausal women, keeps these effects at bay.
In Conclusion
People have different reactions to coffee and its caffeine content. Some take several cups of coffee and feel fine, others need to switch to decaffeinated brands in other to fully enjoy its rich taste and compelling aroma. A few others get their caffeine from non-coffee sources like tea, chocolate, energy drinks, etc. Whatever sources are chosen, the possible long term beneficial or harmful effects remain dose-dependent. Based on available data, no conclusive evidence existed to support the carcinogenic effect claim and none to discourage or promote the use in daily diet of coffee, tea or chocolate. 3 The decision, therefore, is a choice you will have to make.
