If you’re one of the millions of Americans who can’t really get the day going without a steaming cup of coffee, rest assured you’re definitely not alone. An awful lot of people are dependent on that morning java to wake up and be ready to tackle the day.
For many people, it’s the caffeine in coffee that helps them wake up and get moving. “Caffeine is a naturally occurring substance found in more than 60 plants,” says Dr. Sophia Tolliver, clinical assistant professor of family medicine at the Ohio State University Wexner Medical Center in Columbus.
Caffeine can be found in a wide variety of foods and drinks, including:
- Coffee beans
- Tea leaves
- Cacao, cocoa and chocolate products
- Guarana seeds
- Energy drinks
- Matcha powder
- Pre-workout powders
Though coffee has been around for centuries, and humans have been reaching for plants to get a buzz for much longer, caffeine was first isolated from coffee by Friedlieb Ferdinand Runge, a German chemist. In 1819, he became the first to isolate and purify caffeine, which he discovered by studying Arabian mocha beans given to him by Johann Wolfgang von Goethe, the famous German poet.
Since then, study into the effects of this chemical have expanded. “Caffeine can have both beneficial and detrimental side effects, depending on dose,” says Lisa Cooper, a registered dietitian with Orlando Health in Florida. “If taken in moderation, caffeine can increase alertness and reduce tiredness. It can also improve athletic performance by delaying fatigue.”
In fact, caffeine is classed as “a central nervous stimulant” that alters your focus and can make you more alert, Tolliver says.
Caffeine isn’t regulated the ways some drugs are because it’s so widely distributed in various common foods and drinks, and it sometimes turns up where you least expect it. It’s used as an additive in some drinks, such as seltzers and sports drinks, as an alternative to coffee that gives you a caffeine buzz without the bitter taste of coffee.
Despite its general ubiquity and the sometimes lax approach to its potential effects, you should handle caffeine and caffeinated beverage with care as they can impact your health and well-being, both negatively and positively.
Health Benefits of Caffeine
Nutrition science has at various times both vilified and extolled the virtues of caffeine and coffee. Some studies have noted detrimental effects of coffee and caffeine, but sometimes these studies “did not take into consideration that those who drank coffee tended to smoke or were sedentary,” Tolliver says.
More recent studies have tried to control for these factors and have noted that coffee and caffeine may actually offer some health benefits. Some studies have noted that coffee may be associated with a decrease in mortality and have some protective value against a variety of diseases including:
Parkinson’s Disease — A 2010 review study found that higher regular consumption of caffeine was correlated with a lower risk of Parkinson’s. A 2020 study in the journal Neurology looked at whether coffee can protect people with a specific gene mutation that decreases risk of developing Parkinson’s and found a correlation between that genetic mutation and blood caffeine levels.
Type 2 Diabetes — Though some research indicates that caffeine can raise blood sugar and insulin levels for people with diabetes, if you don’t yet have the disease, being a regular coffee drinker could actually lower your risk of developing it. A large 2014 study found that people who increased coffee consumption by more than one cup per day saw an 11% lower risk of developing type 2 diabetes.
Liver Disease — According to a 2017 study, coffee has “hepatoprotective properties,” meaning it can help protect the liver. That investigation found that coffee appears to reduce the risk of liver cancer and may slow the progression of chronic liver diseases.
Heart Failure — The American Heart Association reports that drinking one or more cups of coffee per day may reduce the risk of heart failure, but only if the coffee contains caffeine. That’s according to a 2021 study looking at the connection between heart health and coffee intake.
Stroke — Coffee consumption and risk of stroke have been studied extensively, and results have been mixed. However, a 2018 review study found moderate consumption of coffee was protective against stroke, and a large cohort study that followed 83,000 women over 24 years found significant evidence of coffee decreasing stroke risk.
There’s also some research that suggests caffeine could help delay the onset of Alzheimer’s disease and other types of dementia. In addition, the stimulant effect of caffeine may help support your metabolism, leading to weight loss.
While caffeine certainly has some potential health benefits, it may be that the real value comes from the context of consuming moderate levels of it in coffee or tea rather than just the caffeine itself. There are other elements in coffee and tea that can also impact your overall well-being, and it could be a case of the sum is greater than its parts.
“Health benefits achieved through coffee or tea consumption are generally attributed to the polyphenols and antioxidants,” plant-based compounds that can support cellular health that are present in the beverages, Cooper says.
Negative Health Effects of Caffeine
Caffeine dependency is a real thing, and if you’re used to consuming a certain amount of caffeine on a regular basis and suddenly stop, you’ll likely experience withdrawal symptoms including headaches, insomnia, irritability and tiredness. This means that if you’re a regular coffee drinker, you can experience negative withdrawal effects if you suddenly start drinking less coffee.
At the other end of the spectrum, too much caffeine can be even more problematic. Excessive consumption can lead to:
- Rapid heart rate
- Acid reflux or upset stomach
The U.S. Food and Drug Administration notes that rapid consumption of high levels of caffeine – on the order of 1,200 milligrams per day – could lead to seizures. And Cooper notes that if you consume 10 grams (or 10,000 milligrams) of caffeine – equivalent to what would be found in about 100 cups of coffee – that amount of caffeine can be fatal. A typical 8-ounce cup of drip-brewed coffee contains 100 milligrams of caffeine. “These toxic levels are usually achieved with caffeine powders or pills.”
Tolliver adds that if you’re going to use a concentrated form of caffeine, be very careful. “Powder and liquid forms of caffeine can be very concentrated and should be used cautiously – or not at all.” For example, “one teaspoon of pure powdered caffeine is equivalent to 28 cups of coffee. A half cup of liquid concentrated caffeine is equivalent to 20 cups of coffee. Consumption of caffeine at this level could lead to death.”
How Much Caffeine Is Safe?
Given the wide range of impacts caffeine can have on your health, you’re likely wondering how much is safe and what’s the optimal amount to consume daily. The FDA recommends that healthy adults consume no more than 400 milligrams of caffeine per day. “That’s about four cups of brewed coffee, 10 cans of soda or two energy drinks,” Tolliver says.
But there are some caveats. “People with hypertension should be cautious because caffeine can elevate blood pressure,” Tolliver notes. There has also been some concern about caffeine consumption among pregnant women. The American College of Obstetricians and Gynecologists notes that pregnant women can safely consume up to 200 milligrams of caffeine per day, which is what’s found in about two cups of coffee.
And kids should steer clear of caffeine, especially in the form of high-sugar energy drinks that can pack a lot more caffeine than the average cup of coffee. No safe limits of caffeine have been established for children, and the American Academy of Pediatrics recommends that children not consume caffeine because they may be more susceptible to caffeine’s effects.
There’s also concern about bone health in kids whose bodies are still growing and developing. Some research has shown that caffeine consumption increases calcium excretion from the body, and thus the concern is that lost calcium could inhibit bone formation.
For the majority of people, moderation is the key. “Caffeine still has some risks, however drinking a daily cup of coffee is likely fine to do,” Tolliver says.
What to Do if You’ve Had Too Much
“Coffee is a beloved morning routine for millions of people around the globe,” Tolliver says, but it’s best to “remember to enjoy in moderation.”
However, if you’ve consumed too much caffeine, Tolliver says it’s important to discontinue consuming it for the day and drink lots of water. “Caffeine is a natural diuretic and so your water stores will likely need replacing. Consider an electrolyte replacement drink like Gatorade or Pedialyte to replace important sodium and potassium that you might be peeing out.”
It’ll take a little while for your system to process all that caffeine, Cooper notes. “Caffeine is metabolized differently by individuals based on genetics, health conditions and medications. Caffeine has a half-life of 2 ½ to 4 ½ hours, meaning every 2 ½ to 4 ½ hours the amount of caffeine is reduced to half of the original amount.”
That said, if you know you’ve ingested a dangerous level of caffeine or have severe symptoms, contact your local poison control center or your medical provider immediately.
If your heart is racing or you’re feeling jittery, Tolliver recommends “practicing some mindful breathing exercises and going for some physical activity with a walk or bike ride.”