There’s no shortage of science about the benefits of drinking coffee, and specifically “Italian-style” coffee, aka espresso. In fact, a study published in The Journal of Nutrition looks at the relationship between 20,487 people and their daily intake of espresso. None of the participants had cardiovascular disease or cancer at the beginning of the experiment and each drank around 30 milliliters or more of espresso—which is about the size of one shot—every day for over eight years.
For espresso lovers this is great news, but one thing that’s important to remember, says Lisa R. Young, PhD, RDN, is not to go overboard. While the occasional espresso has plenty of upsides, there are some negative side effects of drinking too much espresso. “It’s very easy to drink too much espresso, especially since they are such tiny cups,” Young says. “It’s easy to get another…and another…”
Another side effect of caffeine releasing your body’s adrenaline is anxiety. Caffeine increases your alertness by blocking the effects of adenosine, a brain chemical that makes you feel tired. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published by the American Psychiatric Association, recognizes caffeine-induced anxiety disorder as a condition in which caffeine interferes with daily functioning.
This one is pretty scary! Too much caffeine may cause your heart to beat faster, or even alter your heartbeat rhythm. This is called atrial fibrillation, which has been reported in young people who consumed energy drinks containing extremely high doses of caffeine.
Espresso can make you feel dehydrated as caffeinated drinks have a mild diuretic effect — meaning that they may cause the need to urinate frequently. Diuretics are substances that cause your body to make more urine than usual, which isn’t necessarily harmful, but worth being mindful of before a long car ride.
Espresso (and coffee) have a well-known laxative effect that has been attributed to the release of gastrin, a hormone the stomach produces that speeds up activity in the colon. However, if you overdo your daily drink, it may lead to loose stools or even diarrhea in some people.
If you need a kick in the pants before exercising, espresso is the easiest way to get that boost. A quick shot, which on average contains about 75 milligrams of caffeine, about 30 minutes before your workout will help give you energy without making you feel too full.
A University of California study found that drinking two espressos enhanced memory consolidation. This then improved long-term memory in the subjects. However, there’s no need to drink more than that, as the study did not find improvements for those who drank more than two cups.
The way to avoid these drawbacks to espresso is pretty simple. You can have too much of a good thing, says Young. “Many people who are healthy can drink up to 400 milligrams of caffeine a day. That’s around four cups of brewed coffee or 5-6 espressos,” she explains.