Studies show that healthy adults can safely consume 400 milligrams of caffeine a day. So, depending on the caffeine content, you can drink up to four cups of coffee in a day.
A healthy adult can consume around 400 milligrams of caffeine daily, which means you can safely have about four cups of coffee in a day unless otherwise advised by your doctor.
Consumption of 200 milligrams of caffeine doesn’t cause any significant harmful effects in healthy people. However, a variety of factors can influence that number, including pregnancy, use of other drugs and sleep deprivation. Pregnant women are recommended not to take more than 200 mg of caffeine per day.
Caffeine is a plant-based chemical that can be extracted from coffee beans, tea leaves and cocoa beans. Experts believe that these plants developed caffeine as a natural insecticide against damaging insects over millions of years. Caffeine can also be made synthetically.
A variety of beverages and medications contain caffeine, such as:
- Coffee and cappuccino
- Tea
- Energy drinks
- Sodas
- Medications in the form of pills and patch
- Chocolates
- Caffeinated mints or gum
- Pre-workout supplements or fat-burners
However, the caffeine content may vary with each product. Caffeine levels in beverages depend on the type of coffee beans and their size, amount of tea leaves used and the coffee brewing time.
Caffeine is classified as a substance that is "generally regarded as safe," or GRAS, by the U.S. Food and Drug Administration (FDA). This means that caffeine is not regulated as a food ingredient by the FDA. It must be listed as an additional ingredient on a drink's label, such as energy drinks. However, the amount of caffeine in the drink does not need to be listed.
What are the benefits of caffeine?
Consuming caffeine in moderation improves physical and mental performance. Additionally, caffeine intake can award the following nutritional values:
- Caffeine is a central nervous system (CNS) stimulant that:
- improves alertness, especially at times when the circadian clock is low after lunch or in the middle of a night shift
- decreases fatigue
- improves concentration and focus, mood, memory, vigilance and general mental function
- According to a 2005 study presented at the Radiological Society of North America, caffeine can increase short-term memory and reaction times.
- Caffeine intake can prevent the risk of suicide.
- Caffeine is noted to reduce the risk of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease.
- It enhances weight loss and boosts the metabolic rate of glucose and increases fat burning.
- However, long-term coffee consumers may notice a reduction in these effects.
- After post workout, the body gets deprived of energy sources, glycogen, so an intake of caffeine can promote glycogen synthesis and build up glycogen in the body.
- Athletes consume caffeine along with carbohydrates to build up glycogen in the body.
- It increases the functionality of the heart by increasing heart rate and contractility and inhibits negative inotropic (decreased heart rate and contractility) and chronotropic (change in heart rate and rhythm) activity caused by adenosine.
- According to studies, it was noted that caffeine may lower the risk of type II diabetes because it decreases insulin resistance and impairs glucose tolerance and liver diseases.
What are the side effects of caffeine?
Excess intake of caffeine may cause anxiety, increased blood pressure and other negative effects, such as:
- Caffeine is addictive and its withdrawal causes headaches, anxiety, craving and depression.
- Caffeine increases diuresis (the process of elimination of water in urine by the kidneys), which leads to dehydration and excessive thirst.
- As caffeine is a central nervous system (CNS) stimulant, excess stimulation causes insomnia and other sleeping disorders.
- Caffeine may increase blood pressure, which leads to dizziness.
- Caffeine increases the risk of
- Heart disease
- Premature ventricular contractions
- Sudden death in patients with coronary artery disease who previously experienced cardiac arrests
- Caffeine is a gastric irritant, and it causes acid reflux leading to heartburn and gastroesophageal reflux disease (GERD), which may also cause nausea, vomiting and diarrhea.
- Though caffeine reduces the risk of type II diabetes, it increases blood glucose levels because it impairs glucose metabolism in people with diabetes.
- According to a study in the American Journal of Clinical Nutrition, the caffeine present in soft drinks may decrease bone mineral density in women.
- Caffeine consumption in kids aged five to seven years old may increase bedwetting.
- Consumption of excess caffeine during pregnancy may affect the fetus, which is highly sensitive to caffeine.
- Caffeine causes dependence on the substance and makes you take in more when its effect wears off.
One should consider caffeine as a drug and use it with caution. People who drink coffee and are ultra-sensitive to caffeine should take small amounts until they find the right amount that doesn’t cause any side effects. This could also mean switching to decaffeinated beverages (decaf) after your second cup of coffee for the day or reading the caffeine content on energy drinks.
References
AASM. Sleep and Caffeine. https://sleepeducation.org/sleep-caffeine/
HPF Institute. Are Caffeine Pills Safe (And Who Shouldn’t Use Caffeine Pills). https://hpfreemanpni.org/are-caffeine-pills-safe/
