Benefits and Risks of Coffee: What’s the Ideal Daily Intake?
People’s relationship with coffee oscillates between love and hate; while many harbor great affection for this beverage that is an integral part of their daily routine, others feel concerned about coffee consumption and the effects of caffeine on their health.
A study conducted by the National Coffee Association in 2023 found that 63% of Americans drink coffee daily, more than any other beverage except water. In the same year, coffee surpassed tea to become the favorite drink in the United Kingdom; according to the British Coffee Association, the UK consumes about 98 million cups of coffee daily, as reported by The Guardian newspaper.
However, on the flip side, many individuals feel uneasy about the amount of coffee they consume. This concern has been exploited by companies like “MudWtr,” which produce mushroom-based beverages, to advertise their products as a “healthier” alternative to regular coffee.
“Coffee has somewhat of a bad reputation,” says Dr. Peter Hayes, Professor of Hepatology at the University of Edinburgh. He points out that current concerns about coffee often refer to the concept of “detoxification,” which involves the idea of ridding the body of accumulated toxic or harmful substances due to lifestyle or dietary habits. However, Hayes notes that this concept is vague and difficult to measure scientifically.
Hayes adds to The Guardian, “Everyone speaks in extremely vague terms,” and emphasizes that “coffee is not poison.”
So, what should we conclude from Hayes’ remarks? What is the suitable amount of coffee to drink? And should we try to reduce it? Here are answers from several experts interviewed by The Guardian in response to these questions.
What Happens When We Drink Coffee?
Dr. Sandra Kirsten, Professor of Molecular Nutrition at Cornell University, explains that the main active component in coffee is caffeine.
Anyone who has had a cup of coffee in the morning is familiar with these effects. As a stimulant, caffeine makes individuals feel more alert, says Kirsten. People’s reaction times become faster, they become more focused, and they have greater endurance. Studies have found that caffeine consumption is associated with improved athletic performance.
According to Kirsten, these effects usually begin within half an hour and last for up to two hours. “This is why people tend to continue drinking coffee throughout the day,” she says, adding that its effects “do not last long.”
What are the Health Benefits of Drinking Coffee?
Experts agree that there are many benefits to morning coffee. Coffee contains “hundreds, if not thousands, of compounds,” says Dr. Edward Giovannucci, Professor of Nutrition and Epidemiology at the Harvard T.H. Chan School of Public Health.
“Some of these compounds may have a range of beneficial effects that may improve health in the long term,” he says. Giovannucci explains that some compounds, for example, have strong anti-inflammatory and antioxidant properties. Others reduce insulin resistance, a risk factor for diabetes.
Analyzing the effects of coffee consumption on health, Hayes and his colleagues found that drinking three to four cups a day was associated with a decreased risk of heart disease, some types of cancer, and conditions of the nervous, metabolic, and liver systems.
The liver appears to be the organ that benefits the most from coffee. One cup of coffee per day can reduce the risk of liver fibrosis by 20%, and five cups a day can reduce the risk by 80%, according to Hayes.
Hayes also points out that it is “important to distinguish between coffee and caffeine.” For example, a coffee drinker can see these benefits even with decaffeinated coffee. “So there’s something in coffee, not caffeine, that protects the liver,” he says, noting that consuming excessive amounts is not a healthy choice despite its benefits at this level.
What are the Negatives of Drinking Coffee?
Giovannucci says that increased coffee consumption can lead to high blood pressure.
In addition, some individuals may be more sensitive to the effects of caffeine than others: “The stimulating effect of coffee can cause anxiety in sensitive individuals and may affect their sleep,” says Giovannucci.
To mitigate its disruptive effects on sleep, experts advise limiting caffeine intake before 5 p.m., says Dr. Kira M. Nemn-Deub, a nutrition expert, food researcher, and nutrition coach.
But the specific timing will depend on your sleep schedule and your body’s sensitivity to caffeine. Nemn-Deub points to a study that found that consuming caffeine up to six hours before bedtime can significantly disrupt sleep and reduce total sleep time by more than an hour.
Hayes says that some individuals, including pregnant women and those with severe osteoporosis, should limit their coffee consumption.
Is there a Limit to the Amount of Coffee One Should Drink Daily?
It seems that consuming up to 400 milligrams of caffeine per day is safe for most adults, according to the Mayo Clinic.
One eight-ounce cup of brewed coffee contains about 95 milligrams of caffeine, says Giovannucci, so this equals about four cups of coffee.
Giovannucci says that above these levels, people may feel tense and experience an increased heart rate – “symptoms that can be felt during a panic attack.”
He adds that individuals with panic disorder or underlying anxiety are particularly prone to experiencing these negative side effects.
On the other hand, Hayes says that drinking two to three cups a day generally serves as the optimal range for reaping the benefits of coffee without being exposed to its negatives. But the ideal amount varies from person to person.
Nemn Deub says, “It’s essential to listen to your body,” adding that each person has a different level of caffeine sensitivity, with some feeling tense after one cup, while others feel better after three cups.
Excessive caffeine consumption can have much more dangerous effects. According to the US Food and Drug Administration, toxic effects of caffeine, such as seizures, have been observed with rapid consumption of 1200 milligrams of caffeine at once.
Accordingly, the administration notes that highly concentrated caffeine products, such as those found in caffeine powders or energy drinks, “pose a significant threat to public health.”
