Caffeine, often called “world’s most popular drug,” is a normal part of many of our daily lives. It is found in the three most popular drinks in the world—coffee, tea and cola—and in other soft drinks, chocolate, and some medications. Scientists say caffeine is not harmful in moderation—up to 250mg a day—as long as it is not consumed close to bed time (within 4-6 hours), which can disrupt sleep.

While caffeine cannot replace sleep, it can temporarily make us feel more alert by blocking sleep-inducing chemicals in the brain and increasing adrenaline production.

This alertness can be helpful in the short term, but caffeine’s negative side effects include:

• “Caffeine crash,” or fatigue once the caffeine wears off

• Feeling of anxiety or irritability

• Rapid heartbeat

• Sleep disturbance due to increased time needed to fall asleep, frequent awakenings during the night, and interference in moving into the deeper, more restorative stages of sleep

How much do you really know about caffeine?