What Is Caffeine, and Is It Good or Bad for Health?

What Is Caffeine, and Is It Good or Bad for Health?

Caffeine is a natural stimulant that’s widely consumed worldwide. it helps you stay awake and can stave off tiredness.

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. That said, caffeine’s main effect is on the brain.

Caffeine is most commonly found in coffee, tea, soft drinks, chocolate and energy drinks.

You can also find caffeine in some prescription or over-the-counter drugs like cold, allergy, and pain medications. It’s also a common ingredient in weight loss supplements. Also Caffeine may improve mood, decrease the likelihood of depression, stimulate brain function, and protect against Alzheimer’s and Parkinson’s disease.

May protect against heart disease and diabetes

Despite what you may have heard, caffeine doesn’t raise the risk of heart disease (26Trusted Source, 27Trusted Source, 28Trusted Source).

In fact, evidence shows a 16–18% lower risk of heart disease in men and women who drink between 1–4 cups of coffee daily (providing approximately 100–400 mg of caffeine) (29).

Other studies show that drinking 2–4 cups of coffee or green tea per day is linked to a 14–20% lower risk of stroke (30Trusted Source, 31).

One thing to keep in mind is that caffeine may slightly raise blood pressure in some people. However, this effect is generally small (3–4 mmHg) and tends to fade for most individuals when they consume coffee regularly (32, 33, 34Trusted Source, 35Trusted Source).

It may also protect against diabetes.

A review noted that those who drink the most coffee have up to a 29% lower risk of developing type 2 diabetes. Similarly, those who consume the most caffeine have up to a 30% lower risk (36).

The authors observed that the risk drops by 12–14% for every 200 mg of caffeine consumed (36).

Interestingly, consuming decaffeinated coffee was also linked to a 21% lower risk of diabetes. This indicates that other beneficial compounds in coffee can also protect against type 2 diabetes (36).


Caffeinated beverages like coffee and tea may reduce the risk of heart disease and type 2 diabetes, although this may depend on the individual.

Other health benefits of coffee

Coffee consumption is linked to several other health benefits:

  • Liver protection. Coffee may reduce the risk of liver damage (cirrhosis) by as much as 84%. It may slow disease progression, improve treatment response, and lower the risk of premature death (37Trusted Source, 38).
  • Longevity. Drinking coffee may decrease the risk of premature death by as much as 30%, especially for women and people with diabetes (39Trusted Source, 40Trusted Source).
  • Decreased cancer risk. Drinking 2–4 cups of coffee per day may reduce liver cancer risk by up to 64% and colorectal cancer risk by up to 38% (41, 42, 43, 44Trusted Source, 45Trusted Source).
  • Skin protection. Consuming 4 or more cups of caffeinated coffee per day may lower the risk of skin cancer by 20% (46Trusted Source, 47Trusted Source).
  • Reduced MS risk. Coffee drinkers may have up to a 30% lower risk of developing multiple sclerosis (MS). However, not all studies agree (48, 49Trusted Source).
  • Gout prevention. Regularly drinking 4 cups of coffee per day may reduce the risk of developing gout by 40% in men and 57% in women (50Trusted Source, 51Trusted Source).
  • Gut health. Consuming 3 cups of coffee a day for as few as 3 weeks may increase the amount and activity of beneficial gut bacteria (52Trusted Source).

Keep in mind that coffee also contains other substances that improve health. Some benefits listed above may be caused by substances other than caffeine.


Drinking coffee may promote a healthy liver, skin, and digestive tract. It may also prolong life and help prevent several diseases.

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 (53Trusted Source).

Too much caffeine may also promote headaches, migraine, and high blood pressure in some individuals (54, 55Trusted Source).

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 (54, 56, 57).

Caffeine can also interact with some medications.

Individuals taking the muscle relaxant Zanaflex or the antidepressant Luvox should avoid caffeine because these drugs can increase their effects (58Trusted Source).


Caffeine can have negative side effects in some people, including anxiety, restlessness, and trouble sleeping.

Recommended dosages

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 (59Trusted Source).

That said, it’s worth noting that fatal overdoses have been reported with single doses of 500 mg of caffeine.

Therefore, it’s recommended to limit the amount of caffeine you consume at one time to 200 mg per dose (60Trusted Source, 61Trusted Source).

According to the American College of Obstetricians and Gynecologists, pregnant women should limit their daily intake to 200 mg (62Trusted Source).


A caffeine intake of 200 mg per dose, and up to 400 mg per day, is generally considered safe. Pregnant women should limit their daily intake to 200 mg or less.

The bottom line

Caffeine isn’t as unhealthy as it was once believed.

In fact, evidence shows that it may be just the opposite.

Therefore, it’s safe to consider your daily cup of coffee or tea as an enjoyable way to promote good health.

Source: https://www.healthline.com/nutrition/what-is-caffeine#heart-disease-diabetes