Arabica coffees have half less caffeine than Robusta. Origin and composition of the blend, as well as the brewing method and the strength of the brew may influence meaningfully caffeine contents in a cup.
Tea and coca drinkers are not free from caffeine consumption. Average caffeine concentration in one cup of tea is usually less than 60-mg. Cocoa and chocolate drinks add for 4-5 mg caffeine per cup.
Caffeine contents in a cup of coffee are said to be stimulant to the nervous system. The effects may vary according to each individual's sensitivity, but coffee drinking is usually associated with feeling awake, alert and able to concentrate. Caffeine is sometimes prescribed for headache, pain relief, appetite control, staying awake, colds, asthma and fluid retention.
Keeping track of how many cups of coffee you drink per day may help you avoid negative physiological effects such as increases in blood pressure, gastric acid, plasma catecholamines, plasma renin and serum free fatty acids.