Coffee, Caffeine and Health

 Brain

• Increases mental performance and vigilance owing to greater alertness
• Contributes to insomnia and induces anxiety (particularly at high doses and in susceptible persons)
• May reduce the risk of depression
• Can augment the effect of NSAIDs and acetaminophen for treating headache and other causes of pain 
• May reduce the risk of Parkinson's disease

Cardiovascular system

• Increases blood pressure in the short term, but at least partial tolerance
• develops with habitual intake

Lungs

• Is effective for treating apnea of prematurity in infants
• Slightly improves lung function in adults

Endocrine system

• Reduces skeletal muscle insulin sensitivity in the short term, but tolerance appears to develop with habitual intake

Liver

• May reduce the risk of liver fibrosis, cirrhosis, and cancer

Kidneys and urinary tract

• High doses can have a diuretic effect, but habitual moderate intake does not substantially affect hydration status

Reproductive system

• May reduce fetal growth and increase the risk of pregnancy loss