Each day, billions of people rely on caffeine to wake up, or to get through that night shift or an afternoon slump. In fact, this natural stimulant is one of the most commonly used ingredients in the world.
Caffeine isn’t as unhealthy as it was once believed. In fact, evidence shows that it may be just the opposite.
Caffeine is often talked about for its negative effects on sleep and anxiety. However, studies also report that it has various health benefits. Caffeine is a natural stimulant most commonly found in tea, coffee, and cacao plants.
It works by stimulating the brain and central nervous system, helping you stay alert and prevent the onset of tiredness.
How it works
Once consumed, caffeine is quickly absorbed from the gut into the bloodstream. From there, it travels to the liver and is broken down into compounds that can affect the function of various organs. Caffeine’s main effect is on the brain. It functions by blocking the effects of adenosine, which is a neurotransmitter that relaxes the brain and makes you feel tired.
Caffeine helps you stay awake by connecting to adenosine receptors in the brain without activating them.
It may also increase blood adrenaline levels and increase brain activity of the neurotransmitters dopamine and norepinephrine.
The amount found in one cup of coffee can take as little as 20 minutes to reach the bloodstream and about 1 hour to reach full effectiveness.
May improve mood and brain function
Caffeine may improve mood, decrease the likelihood of depression, stimulate brain function, and protect against Alzheimer’s and Parkinson’s disease.
When it comes to mood, more caffeine isn’t necessarily better. A study found that a second cup of coffee produced no further benefits unless it was consumed at least 8 hours after the first cup.
May boost metabolism and fat burning
Because of its ability to stimulate the central nervous system, caffeine may increase metabolism by up to 11% and fat burning by up to 13%.
May enhance exercise performance
Caffeinated beverages like coffee and tea may reduce the risk of heart disease and type 2 diabetes, although this may depend on the individual. When it comes to exercise, caffeine may increase the use of fat as fuel.
This is beneficial because it can help the glucose stored in muscles last longer, potentially delaying the time it takes your muscles to reach exhaustion.
Coffee consumption is linked to several other health benefits:
• Liver protection. Coffee may reduce the risk of liver damage (cirrhosis). It may slow disease progression, improve treatment response, and lower the risk of premature death
• Decreased cancer risk. Drinking 2–4 cups of coffee per day may reduce the cancer risk
• Gout prevention. Some research suggests that drinking coffee in moderation, especially regular caffeinated coffee, may be associated with a reduced risk of gout.
Safety and side effects
Caffeine consumption is generally considered safe, although habit forming.
Some side effects linked to excess intake include anxiety, restlessness, tremors, irregular heartbeat, and trouble sleeping.
Too much caffeine may also promote headaches, migraine, and high blood pressure in some individuals.
In addition, caffeine can easily cross the placenta, which can increase the risk of miscarriage or low birth weight. Pregnant women should limit their intake.
Caffeine can also interact with some medications.
Both the U.S. Department of Agriculture (USDA) and the European Food Safety Authority (EFSA) consider a daily intake of 400 mg of caffeine to be safe. This amounts to 2–4 cups of coffee per day.