Caffeine is one of the most commonly consumed ingredients in world. It is estimated that >90% of adults worldwide consume caffeine daily. Caffeine, in its pure form is a very bitter white powder, and can be found in leaves and beans of over 60 different types of plants.

Caffeine is a psychostimulant that affects chemicals in the brain called Neurotransmitters. When these chemicals are over stimulated, the affects can be felt in many body organs. Caffeine is completely absorbed by the body in about 30-45 minutes, and lasts about 3 hours in the normal body system. Factors that can affect the metabolism of Caffeine are impaired kidney function, age, other chronic illnesses and some medications. Caffeine is excreted through the kidneys, so it is not stored in the body.  Caffeine use can cause dependence.

Caffeine decreases blood flow to the brain. People who consume too much caffeine can have symptoms such as nervousness, tremor, restlessness, sweating, irritability, urinary frequency and stomach upset. Many people find it hard to sleep if consuming caffeine less than 3 hours before bedtime.

If too much caffeine is consumed, there may be an abnormal rise in heart rate and blood pressure. Caffeine can decrease the amount of blood that flows to the brain tissue, resulting in reduced intracranial pressure. There is one case report in the literature of death from a fatal dose of caffeine (more than 10 gms).

There is much controversy over how much Caffeine is too much. Although this is still under debate, the following guidelines (from ) may be helpful:

  • Low-mod intake= 130-300mg/day
  • moderate intake=200-300mg/day
  • High intake= >400mg/day
  • Heavy consumption > 6000mg/day