Coffee is one of the beverages that has more very ancient data compiled about it. It has been said to have beneficial effects but also negative ones. Historically, coffee has been at the center of many popular beliefs, not always scientifically proved, which have caused skepticism. Nonetheless, there is scientific evidence that moderate coffee consumption is not only completely safe but also can have health benefits.
Some of the references obtained from relevant research studies are:
- Coffee and bronchial asthma. It has been discovered that caffeine prevents moderate attacks of this respiratory illness. The study carried out in the U.S.A. and in Italy support the theory that drinking coffee improves the ventilation function in induced bronchoconstriction, monitoring that its consumption does not cause over-stimulation to persons susceptible to it.
- Coffee is a good antioxidant. In addition to caffeine, coffee has other components that, the same as in other plants, has antioxidant properties. Flavonoids (derived polyphenolics) provide an important protection against possible illnesses and also act as a defense mechanism against diverse attacks by microorganisms,
- Coffee sharpens vigilance and raises a person´s mood. Numerous studies show that coffee with caffeine stimulates attention and liveliness and betters performance, during the day as well as at night. Similarly, it counteracts the effects of tiredness in drivers.
- Coffee reduced the risk of kidney stones. After numerous studies, scientists concluded that a specific consequence of coffee is the metabolic effect that can reduce the formation of biliary stones since other drinks with a higher or lower caffeine concentration did not show any significant relation. Additionally, it has been proven that drinking coffee increases the elimination of water and minerals through the urine.
- Coffee reduces the risk of colon cancer. After numerous studies, Swedish scientists concluded that coffee consumption seemed to protect against colon cancer, while tea did the same for rectal tumors. A study in Italy reached the same conclusion.
- Caffeine acts against migraine headaches and boosts certain pain-killing medicines. Caffeine does not alter cardiovascular functions nor does it raise blood pressure in healthy persons.
- Caffeine facilitates the digestive process by stimulating gastric secretion and pancreatic exocrine secretion.
Caffeine and sports. Caffeine produces a maximum stimulating effect for 2 - 4 hours after drinking it and:
- It causes an increase in physical performance because the organism uses body fat as a energy source. That is why it should not contain sugar as sugar provokes a raise in blood sugar and insulin which inhibits the use of fat.
- It reduces the sensation of fatigue, increases precision, agility and coordination, and boosts muscular contractibility mobilizing calcium. The International Olympic Committee authorizes a limit of 12 micrograms/ml., about 8 cups (1000 mg. caffeine)
Caffeine content and physiological effects
The amount of caffeine in a cup of coffee can vary greatly depending on the origin or the coffee and it mixture and the elaboration method. Instant or soluble coffee generally has less caffeine than roasted or ground coffee.
Generally, the amount of caffeine consumption is less than 300 mg/day, which is more or less:
- 3-4 cups of roasted and ground coffee
- 5 cups of instant coffee
- 5 cups of tea.
Shortly after drinking a cup of coffee or tea, the caffeine is distributed throughout the body (nervous system, cardiovascular system, respiratory system, etc.). However, the body does not store caffeine so its effects are short-lived.
Each person reacts differently to caffeine. For example, caffeine can stay in the body of pregnant women three times longer than normal in adults while smokers eliminate caffeine twice as rapidly as non-smokers.
The body can become accustomed to caffeine and regular users are less sensitive to its stimulating effects than others. In fact, people tend to regulate their coffee consumption depending on their experience - they drink many cups of coffee in the morning for the stimulating effect, and none in the evening hours before bedtime.
Of all of the physiologic effects of coffee the most well known is as a stimulant of the nervous system. One or two cups of coffee can make one feel more awake, alert and able to concentrate. Caffeine has been proven to counteract fatigue and increase performance. Nevertheless, in those persons sensitive to caffeine, it can delay sleep, decrease sleep time and even lessen the quality of sleep. Caffeine also has various effects on the way a person feels, which can go from pleasurable stimulation and a better mood to anxiety, nervousness and irritability. However, these effects are temporary and depend on the amount of caffeine consumed.
Other short-term physiologic effects of caffeine include an increase in blood pressure, of plasma catecholamines, renins and free fatty acids in serum; the production of urine and gastric acids also increases. Those healthy individuals who regularly consume caffeine achieve tolerance and do not have any adverse effects.
The great majority of scientific and epidemiologic data have reached the conclusion that regularly consuming coffee and other drinks with caffeine is not associated with cardiovascular illnesses, fetus damage, benign breast cancer or cancer of any other type.
Gene or region studied