Is Coffee Good For You? Here’s What The Research Says

Is coffee a wonder drug, or should you be cutting way, way back?

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Dunkin’ Donuts likes to tell us that America runs on Dunkin’, but let’s face it: Americans will run on any old coffee. An estimated 54 percent of us over the age of 18 drink at least one cup daily, and most coffee drinkers are sucking down at least three cups of joe each day. Coffee consumption is a $40 billion business, according to a 2010 report from the National Coffee Association, but what are we really drinking? And is coffee good for you, or are the side effects outweighing that sweet caffeinated boost?

What is coffee, anyway?

There’s an old dad joke that coffee is a bean, so it’s a good way to get your vegetables. Technically, coffee does come from a coffee bean, but the bean part of that phrase is a bit of a misnomer. Coffee beans are really seeds from the coffee cherry, which grows on the flowering coffee fruit tree. So in reality, coffee is a fruit product. The National Coffee Association traces the origin of our favorite pick-me-up beverage back to ancient times, when a goat herder named Kaldi supposedly noticed that his goats were eating “berries” from a particular tree and showing signs of high energy after their snacking. The berries were, of course, what we now know as coffee cherries, and whether the legend is true or not, it’s clear that at some point in history, people started looking to coffee beans as a means for getting caffeine into their exhausted bodies. By the 15th century, coffee was a tradeable good on the Arabian peninsula, with the Turkish word kahve and the Arabic word qahweh eventually giving rise to the English coffee.   The drink had hopped continents to Europe by the 17th century and came across the Atlantic shortly thereafter, making its way to America thanks to the help of the British sometime in the 1600s. The infamous tea tax that prompted the Boston Tea Party (and eventually the American Revolutionary War) buoyed coffee’s popularity in America and got us hooked on java. That’s when coffee consumption became as much your patriotic duty as means of fight fatigue, and a nation of coffee drinkers was born. Of course, the fact that coffee will wake you up in the morning didn’t exactly hurt in making coffee our go-to beverage. “The main active compound in coffee is caffeine, which stimulates the central nervous system and makes us more alert,” explains registered dietitian Travis King. And just one cup of coffee can pack a whole lot of caffeine. A venti (20 oz) of Starbucks’ Blonde Roast boasts 475 milligrams of caffeine, whereas a standard Green Mountain Keurig K-Cup will infuse 75 milligrams of caffeine into just eight ounces of brew. There’s no question that we love the jolt that we get from coffee, but what is all our coffee consumption doing to our bodies?

Is coffee good for you?

If you go by the constantly changing headlines, coffee can do a whole lot of harm—or a whole lot of good—to the body. A study published in the Annals of Internal Medicine just this past August, for example, suggests that coffee drinkers live longer than people who stick with tea or water. Funded by the National Cancer Institute, the researchers looked at more than 180,000 American adults ages 45 to 75 and their coffee drinking habits. They then looked at mortality statistics, including deaths due to heart disease, cancer, respiratory disease, stroke, diabetes, and kidney disease. Their conclusion? “Higher consumption of coffee was associated with lower risk for death in African Americans, Japanese Americans, Latinos, and whites.” Another study, also published in the Annals of Internal Medicine and funded by the European Commission Directorate-General for Health and Consumers and International Agency for Research on Cancer, took a look at the impact of coffee drinking by more than half a million Europeans in 10 different countries. The researchers considered everything from liver function to inflammation and metabolic health, splitting up men and women to see if coffee had different effects based on gender. In the end, they came up with similar results: “Coffee drinking was associated with reduced risk for death from various causes.” So coffee is a magical elixir that will save—or at least extend—your life, right? Not so fast. “It’s been called a wonder drug, and it’s been called a carcinogen,” says Ruth Kava, PhD, RD, a senior nutrition fellow at the American Council of Science and Health. “It’s all over the map.” But the answer lies somewhere in between, and one of the major issues with caffeine research and data is how studies are performed. Most coffee studies are retrospective, Kava tells HealthyWay. That means that people are being asked to report their past activities—for example, how much coffee they drink—to researchers after the fact. “Maybe you’re going to remember that accurately, maybe you’re not,” Kava points out. What’s more, retrospective studies can be skewed by a participant’s fear that the researcher will judge their answers, meaning they may under- or overreport their coffee consumption. That makes all of the results that claim to show coffee is good for you a mixed bag. Kava’s analysis of all the studies out there? Coffee isn’t magic, but it does have its benefits, at least when it comes to the caffeine portion of the equation. Being alert, of course, is a good thing. It means we have better reaction times, we’re more vigilant, and we’re usually better able to perform our day-to-day tasks. A registered dietitian herself, Kava drinks coffee in the morning as a wake up, as do 43 percent of Americans who turn to caffeine to combat “daytime sleepiness.” The U.S. Food and Drug Administration (FDA) gives limited caffeine intake the rubber stamp. Although there is no official guideline from any federal agency on how much coffee to drink for health, the FDA espouses adult consumption of up to 400 milligrams of caffeine a day “as an amount not generally associated with dangerous, negative effects.” If you’re constantly hitting the coffee cart at work, there’s good news here: 400 milligrams is equal to about four or five cups (as in measuring cups—not paper cups or mug refills) of coffee per day. Even the American College of Obstetrics and Gynecology (ACOG) has given pregnant women leave to consume some coffee during their pregnancies. In a committee opinion issued in 2010, the OB-GYN group noted, “Moderate caffeine consumption (less than 200 mg per day) does not appear to be a major contributing factor in miscarriage or preterm birth.” And while the doctors did note that caffeine can cross the placenta to the baby, the official opinion states that the crossover “does not cause a decrease in uterine blood flow or fetal oxygenation.” Pregnant women are advised to speak directly with their medical caregivers before consuming caffeine, but the ACOG leaves the door open for a bit of java consumption during pregnancy. Even if you’re not pregnant, the amount of coffee you should drink (or whether you should consume any at all) should come down to a talk with your medical practitioner, but Kava is quick to advise that women not jump on the coffee bandwagon hoping it will cure them of their ills. “For the average, relatively healthy adult, moderate consumption is not going to hurt you, but it’s not going to cure all your ailments,” she says.

Is coffee bad for you?

Did you notice Kava said coffee consumption is okay for the average, relatively healthy adult? The key word here is adult. Even the doctors who say coffee is okay to drink (and that it can give you a much-needed wake-up call in the morning) are adamant that coffee is likely bad for children. Almost three-quarters of kids consume caffeinated beverages every day, according to a study published by the American Academy of Pediatrics (AAP), with energy drinks and coffee leading the pack in terms of kids’ caffeinated beverages of choice. But if you have a child at home who is begging you to just let them tag along on the next Starbucks trip because “Everyone else is,” it’s okay to stand firm, even if you’re a coffee drinker yourself. According to the AAP, the risks of coffee (and other caffeinated beverages) to kids is limited, but so far, studies on coffee and caffeine intake have largely focused on adults. The AAP study does report cases of caffeine toxicity and deaths, as well as the risk of tachycardia, arrhythmia, hypertension, hyperactivity, anxiety, and increased blood sugar concentrations as reasons kids should not drink coffee or other caffeinated beverages. And it isn’t just kids who can suffer from coffee’s side effects—or the side effects from whatever’s added to your coffee. “The antioxidants in coffee have been linked to a decreased risk of type 2 diabetes, Parkinson’s disease, myocardial infarction, and cirrhosis,” says Matthew Kunar, DO, a family practitioner with OhioHealth Primary Care Physicians. “However, there is some evidence that shows adding sugar and non-dairy creamer to your coffee may decrease the antioxidant effects.” Those additives in coffee can add up, Kava points out. If you’re sweetening your coffee with spoonfuls of sugar, you might want to take a look at just how much you’re increasing your sugar consumption, because doing so can be linked to obesity, heart disease, and more. The idea that coffee consumption should be limited to less than 400 milligrams of caffeine, per the FDA guidelines, is also not to be ignored. If nothing else, limiting your coffee intake could help you sleep better. Studies have found that the fatigue-fighting benefits of caffeine end up costing us when we drink too much coffee (or drink it too close to bedtime), basically creating a vicious cycle of being tired, drinking coffee to combat it, struggling to sleep, being tired, and going for another pour. “Caffeine, especially within four to six hours of sleep, can cause insomnia, so I usually advise against an afternoon cup of coffee if it’s interfering with sleep quality,” King points out. Depending on how much you drink, or how your body reacts, the stimulating effects of caffeine can also be considered a drawback. “Everyone’s response to caffeine is different, so some people will feel more anxious, jittery, and have a rise in blood pressure from a small amount of coffee,” King explains. If you’re feeling shaky or overstimulated, it’s suggested you cut back on your intake—or cut it out of your life entirely. It’s important to note that not all coffee-beverages are created equal. A study conducted by researchers at the Second University of Naples’ Department of Experimental Medicine found that espresso increased parasympathetic nervous system activity in healthy young people, but regular coffee didn’t. Clearly your next coffee shop order should be guided by your own health and wellness goals. The good news? Many of studies that slam coffee as something harmful are much like those that declare it a wonder drug, Kava says. They’re retrospective or just plain inconclusive. “It’s really kind of a mishmash of studies,” she points out.

The Bottom Line

While grabbing a coffee is a trendy way of socializing and can feel like an indulgent pick-me-up, coffee drinking also manages to get a bad rap. Despite the mixed messages on our relationship with the beloved bean, at the end of the day, most doctors give coffee the thumbs up, at least when you stick to a few cups a day rather than slurping it down from dawn to dusk. As Kava points out, “You can drink too much of anything!” If you’re worried about how much coffee you drink, you may want to talk to your doctor about it. They can help you devise a plan to kick a caffeine habit that’s gone too far without having adverse withdrawal effects. And if you’re convinced you need to go it alone, don’t be too hasty. “I wouldn’t recommend trying to quit cold turkey,” warns Trude Brinley, a registered dietitian at OhioHealth Grady Memorial Hospital. “That can lead to severe headaches!” Instead, she suggests switching to half-caff beverages—a blend of regular and decaf coffee—or ordering a small cup rather than the large. “Then start taking it down little by little,” she says. Replacing coffee with water will definitely make your doctor happy (how often do we hear how much we need to hydrate?) Tea may be another obvious alternative, but be aware: Teas often have caffeine in them as well, unless you opt for completely herbal varieties. That said, they are a good middle ground between coffee and going caffeine-free, if that’s what you need. “Teas, especially green teas, are associated with a lot of the benefits of coffee with a more moderate dose of caffeine, so some people may not experience as strong negative side effects with tea,” King says. “Other infused drinks, like guayusa and yerba mate, are becoming more popular as sources of caffeine that are claimed to have a variety of benefits, but these haven’t been researched as extensively, so take health claims with a grain of salt.”

Jeanne Sager
Jeanne Sager is a writer and photographer from upstate New York. She has strung words together for The New York Times, The Washington Post, The Atlantic, and more.