Here are 10 lesser-known facts about caffeine:
(1) Decaf isn't the same as caffeine-free. Decaf coffees still contain caffeine ranging from 8.6mg to 13.9mg, compared to 95mg to 200mg in regular coffees.
(2) It takes 30 to 60 minutes for caffeine to reach its peak level in the blood, and 3 to 5 hours for our body to eliminate half of it. The remainder can linger for 8 to 14 hours.
(3) Caffeine affects people differently. Women generally metabolize caffeine faster than men. Smokers process it twice as quickly as nonsmokers do. Women taking birth control pills metabolize it at perhaps one-third the rate that women not on the Pill do. Asians may do so more slowly than people of other races.
(4) One might think that energy drinks would pack loads of caffeine. On the contrary, they contain considerably less than an old-fashioned cup of black coffee. An 8.4-ounce serving of Red Bull, for instance, has a relatively modest 76 to 80mg of caffeine, compared to 95mg to 200mg in a typical cup of coffee.
(5) Dark roasted coffees have less caffeine than lighter ones. This is because the roasting process burns off caffeine. So if you prefer less caffeine then you might opt for dark coffee.
(6) Caffeine is found in more than 60 plants. Tea leaves, kola nuts (which flavor colas), and cocoa beans all contain caffeine.
(7) All coffees are not created equal. It varies from brand to brand. For example, McDonald's coffee had 9.1mg per fluid ounce, while Starbucks' contains 20.6mg per fluid ounce.
(8) 80% of American adults consume caffeine each day, with average intake of 200mg, equivalent to 2 five-ounce cups of coffee or 4 sodas.
(9) Finland takes the crown for the country with the highest caffeine consumption, with the average adult taking 400mg each day. Worldwide, 90% of people use caffeine in some form.
(10) You can intake caffeine not just from drinks. Even though more than 98% of caffeine intake comes from beverages (like coffee, cola, etc), certain foods, such as chocolate (one-ounce milk chocolate bar contains about 5mg of caffeine), and medications can also contain caffeine.