The video explains how caffeine is the world's most widely used psychoactive substance, and it stimulates the central nervous system by blocking adenosine molecules responsible for slowing down the central nervous system before we sleep. Caffeine occurs naturally in coffee beans, tea leaves, cacao beans, and some tree nuts, and people have been consuming it for centuries. Today, caffeine can be found nearly everywhere, and more and more caffeine-infused products are hitting the shelves every day. While caffeine may provide great benefits, such as increased focus, alertness, and energy, it comes with considerable risks just like any other substance.

Caffeine - All About Coffee - National Geographic

caffeine-all-about-coffee-national-geographic

Let's do English ESL basic listening: focus on hearing. The video explains how caffeine is the world's most widely used psychoactive substance, and it stimulate…