Caffeine is also an outlier as its use is seen as socially acceptable in most cultures and even encouraged in others, particularly in the Western world. Caffeine has both positive and negative health effects. It can treat and prevent the premature infant breathing disorders bronchopulmonary dysplasia of prematurity and apnea of prematurity. Caffeine citrate is on the WHO Model List of Essential Medicines. It may confer a modest protective effect against some diseases, including Parkinsons disease. Some people experience sleep disruption or anxiety if they consume caffeine, but others show little disturbance. Evidence of a risk during pregnancy is equivocal; some authorities recommend that pregnant women limit caffeine to the equivalent of two cups of coffee per day or less. Caffeine can produce a mild form of drug dependence – associated with withdrawal symptoms such as sleepiness, headache, and irritability – when an individual stops using caffeine after repeated daily intake. Tolerance to the autonomic effects of increased blood pressure and heart rate, and increased urine output, develops with chronic use (i.e., these symptoms become less pronounced or do not occur following consistent use).Caffeine is classified by the US Food and Drug Administration as generally recognized as safe. Toxic doses, over 10 grams per day for an adult, are much higher than the typical dose of under 500 milligrams per day.
Examples include Oaks Ice Coffee and Farmers Union Iced Coffee. The amount of caffeine in these beverages can vary widely. Caffeine concentrations can differ significantly from the manufacturers claims. Chocolate
Chocolate derived from cocoa beans contains a small amount of caffeine. The weak stimulant effect of chocolate may be due to a combination of theobromine and theophylline, as well as caffeine. A typical 28-gram serving of a milk chocolate bar has about as much caffeine as a cup of decaffeinated coffee. By weight, dark chocolate has one to two times the amount of caffeine as coffee: 80–160 mg per 100 g. Higher percentages of cocoa such as 90% amount to 200 mg per 100 g approximately and thus, a 100-gram 85% cocoa chocolate bar contains about 195 mg caffeine. Tablets
Tablets offer several advantages over coffee, tea, and other caffeinated beverages, including convenience, known dosage, and avoidance of concomitant intake of sugar, acids, and fluids. A use of caffeine in this form is said to improve mental alertness. These tablets are commonly used by students studying for their exams and by people who work or drive for long hours. Other oral products
One U.S. company is marketing oral dissolvable caffeine strips. Another intake route is SpazzStick, a caffeinated lip balm. Alert Energy Caffeine Gum was introduced in the United States in 2013, but was voluntarily withdrawn after an announcement of an investigation by the FDA of the health effects of added caffeine in foods.