Caffeine is a chemical substance extracted from the leaves,beans and fruits of some plants, and primary sources of caffeine includes a coffeeplant, tea bush, guarana berries, kola nut and yerba mate. Coffee,tea, cola, chocolate and energy drinks products are known for its high contentof caffeine. Most people use caffeine to stay awake and boost mentalalertness, but it is also used with pain-killers to treat migraines and headaches. Someuse it to improve the conditions such as low blood pressure, diabetes (type 2),asthma, gallbladder disease, ADHD (attention-deficit hyperactivity disorder)and promote weight loss, while as a cream ingredient, it relieves redness and itchingin dermatitis. Some may even abuse large doses of caffeine in combination withephedrine as an illegal stimulating substance. In hospitals, caffeine can be administered intravenously torelieve shortness of breath in newborn babies, promote urine flow or to treat theheadache after epidural anesthesia.
Caffeine is also used by athletes as a stimulant, and the limitationproscribed by the National Collegiate Athletic Association allows thedoses equivalent to about 8 cups of coffee. Caffeine stimulates the central nervous system, the heart,muscles and the centers controlling blood pressure, and, although caffeine is knownto increase blood pressure and urination, it won’t have this effect on peoplewho use it on regular basis. Moderate doses of caffeine are considered safe, but still, theymay produce side-effects such as insomnia, nausea, vomiting, nervousness andrestlessness. Caffeine can also irritate the intestine, speed up the heartrate, and aggravate sleep disorders. Larger amounts can lead to chest pain,ringing in the ears, headaches, anxiety, agitation, and in extreme casesirregular heartbeats and death.
For most people the caffeine in 2-4 cups of coffee is not consideredharmful. Pregnant and breast-feeding women are advised to limit theirdaily intake of caffeine to 1-2 cups of coffee, while larger doses might lead to amiscarriage in pregnant women or cause the irritability and sleep disturbancesin infants since caffeine can pass into breast milk. Anxiety and bipolar disorders are made worse when consumingtoo much caffeine. People with bleeding disorders, heart conditions, diabetes,glaucoma and high blood pressure are advised to use caffeine with caution, or even to avoid it completely, while people suffering from osteoporosis or low bone density,should stick to 2-3 cups of coffee at most, since calcium is lost in the urinedue to caffeine consumption. They are also advised to take calcium supplements.Women with disrupted vitamin D metabolism should also be careful when takingcaffeine.