4 JUNE, 2013

Myths and truths about coffee

Coffee consumption is an enjoyable experience for millions of people around the world. The coffee tree is most likely from Ethiopia, where it was discovered around 600 A.D. According to legend, a shepherd in Abyssinia (Ethiopia), named Daldi, noticed that his goats were «dancing» on their hind legs after eating some red berries. Kaldi then took the coffee beans to a local monastery, where the monks used them in order to remain altert during their prayers. It is thought that before coffee was appreciated as a drink, natives possibly chewed on the mature cherries and theirs beans for food. Todya, it is certain that coffee is one of the most popular natural drinks enjoyed by consumers on all continents and from every culture. There were moments in coffee’s history where it was revered as a panacea and other’s where it was condemned as the devil’s food – the latter was typically for cultural or religious reasons, when cafes were at the height of their popularity as meeting places.

Coffee plays an important role today in many societies around the world. But what is the truth about coffee?
The coffee tree is a tropical bush that belongs to the Coffea genus of the Rubiaceae family. The tree bears flowers and fruit on the same branch simultaneously. The coffee flower’s life cycle is approximately on day, since as it evolves it transforms into small berries known as cherries. The cherries hide in their core two valuable grains, from which we produce coffee. They are egg shaped and as they grow and mature, the coffee cherries change colors, from green, to yello, and finally to fire red. It takes time and effort in order roasted coffee beans to reach the consumer. Coffee beans much be selected, cleaned, dried and some varieties must even be aged. Coffee is usually roasted prior to consumption and the coffee roasting is a complicated process that creates unique flavor.

So, does coffee ultimately only give us flavor? Even though coffee’s aroma and flavor have been recognized for at least one thousand years, studies regarding coffee consumption and health have only been conducted in the second half of our century. Coffee’s nutritional value includes water and minute amounts of proteins, carbohydrates and fats. The main important ingredients in coffee are polyphenol antioxidants, caffeine and some inorganic salts.

The main focal points when discussing coffee in relation to health are:

1. Caffeine
2. Antioxidants 

1. Caffeine

Caffeine is a natural ingredient of tea, coffee, cocoa and chocolate products, while it is added into soft drinks and various prescription drugs and medication.

 

Type of Coffee

Caffeine Quantity

(per 100 ml)

Caffeine Quantity

(per cup servced)

Filter

50 mg

75 mg (in 150ml of coffee)

Espresso

133 mg

40 mg (in 30 ml of coffee)

Instant coffee (nescafe, frappe)*

40 mg

80 mg (in 200ml of coffee)

Decaf

1,5 mg

3 mg (in 200ml of coffee)

Greek coffee

62,5 mg

50 mg (in 80 ml of coffee)

*Content varies depending on the amount used, which is usually greater than that

For some people the caffeine contained in their coffee provides their necessary daily stimulant, while for others, due to a common misunderstanding, it contributes to high blood pressure, cholesterol etc. In reality, caffeine is certainly a substance that acts on the central nervous system, thus activating it. The degree to which it affects the central nervous system is related to the amount of caffeine consumed, meaning, how much coffee one drinks. Some people may be especially sensitive to caffeine’s effects and some groups of people, for example, pregnant women, should control their caffeine intake. The European Commission’s Scientific Committee on Food conducted a survey on the effects of caffeine on the human health in 1999. Experts concluded that moderate caffeine intake is not associated with adverse health effects in healthy adults (moderate is defined as no more than 5.4 cups of coffee a day).

However, many incriminate coffee, connecting it to two health issues:

Increased Blood Pressure

Coffee’s association with increased blood pressure is a topic speculated upon by the scientific community. Results from studies show that increased blood pressure occurs only if the daily coffee consumption exceeds 400 mg of caffeine, meaning, 5-6 cups of instant coffee. Thus, data shows that blood pressure increase can be caused when consumed 4-5 cups of coffee every day, while many studies show that even when consuming 4-5 cups of coffee a day, it does not cause long term blood pressure increase, but rather only for a two week period.

Cholesterol Increase

One of the most undesired side effects associated with coffee consumption is cholesterol increase. This inccrease is mainly due to coffee’s following two ingredients: cafestol and caveolae. Something important to note though is that these two ingredients cannot be passed through the paper filter when making coffee. Thus, cholesterol increase cannot be attributed to filter coffee. Also, in the studies that show that coffee (instant coffee or greek) can cause the increase of cholesterol, the doses used were very large, the equivalent of over 10 small cups of coffee a day.

2. Antioxidants

One of the most important discoveries regarding coffee’s ingredients are the important substances with strong antioxidant activity. The main ones of these are chlorogenic acids (polyphenols.) Typical values range from 0.5-2.4 gr per 100 grams for roasted coffee and 1-4.5 grams in instant coffee. One cup of coffee (150 ml) usually has approximatley 120 mg of chlorogenic acids. Antioxidants are found in all types of coffee, regardless of the origin, roasting and grinding method, and whether or not the coffee is instant or decaffeinated. The quantities vary depending on the coffee’s origin, the blend, the production and fermentation method.

Typical chlorogenic acid content in coffee

Coffee Type

Typical Serving Amount (mL)

Typical chlorogenic acid content per cup

(mg)

Filter Coffee

150

120

Espresso

25 – 30

88

Instant

180

70

We must also note that compared to other drinks that we know are rich in antioxidants, such as cocoa, green tea, black tea or herbal tea, coffee has exhibits a much higher total antioxidant activity.




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