A little boost from a morning cup of coffee may be a welcome stimulant on a busy day and even offer health benefits for some people, but how much caffeine is too much?
The answer varies from person to person, but overall, experts say it’s safe for a healthy person to consume about 400 milligrams of caffeine per day. That amounts to about four or five cups of regular coffee, says dietician Bonnie Jortberg, PhD, RD, CDCES, associate professor family medicine at the University of Colorado School of Medicine.
“There have been some unfortunate circumstances where people have consumed too much caffeine and have an underlying health condition, but for most people, it’s fine to have a moderate amount of caffeine through tea, coffee, or a soft drink,” she says.
In 2022, a 21-year-old student from Pennsylvania died after unknowingly drinking a highly caffeinated lemonade sold by Panera Bread.
The student, who friends and family say avoided caffeinated drinks at her doctors’ advice because of a heart condition, experienced cardiac arrest hours after finishing the 30-ounce “Charged Lemonade,” which contains about 390 milligrams of caffeine, according to the restaurant chain. A new lawsuit alleges that inaccurate marketing failed to warn consumers about the caffeine contents of the lemonade.
For comparison, most sodas contain about 30 milligrams of caffeine per 12 ounce can and energy drinks contain around 100 milligrams of caffeine per serving.
Knowing your limit and how much caffeine is in a drink is important, Jortberg says.
“Moderation really is key when it comes to caffeine intake,” she explains. “Pay attention to your own reaction and symptoms because it might be the underlying reason why you’re not sleeping well at night or feeling a bit anxious during the day. It can absolutely make a difference.”
Buzzy benefits and drawbacks
For each individual, the effects of caffeine can vary greatly. Some people may be able to drink caffeine well into the evening with no impact on sleep, while others may want to cut it out completely to avoid symptoms like jitteriness, agitation, and anxiousness.
Caffeine, a natural chemical with stimulant effects, primarily affects the nervous system, but it can also effect the cardiovascular system, and the heart in particular. Increasing heart and blood pressure may be detrimental to some people.
“For most people, caffeine makes you feel alert and awake,” Jortberg says. “It increases your heart rate a little bit, increases blood flow, and that’s why you can have those feelings of alertness.”
Research has pointed to caffeine having a bevy of health benefits, including enhanced athletic ability, protection against brain diseases, and longevity.
When caffeine poses a problem
While most people won’t experience a significant negative reaction to caffeine, it can pose serious problems for some.
“If you’re experiencing a very rapid heartbeat or dizziness, those can be signs that your blood pressure is too high and you should seek out medical attention,” Jortberg says.
For those who are sensitive to the effects of caffeine, it can be helpful to look at labels and investigate how much caffeine a product contains. Cacao, coffee-flavored ice cream, and energy bars may include caffeine.
“Caffeine may not be sneaking into our diets as much as sugar is,” Jortberg says. “But it may be in things you might not suspect at first. If you’re experiencing symptoms associated with caffeine intake, like jitteriness or disturbed sleep, it’s worth looking at the food you eat to see if that’s the cause. Just being mindful is the key takeaway here.”