Americans drink a lot of coffee: More than 60 percent sip a mug or more daily. Recent news headlines tell us that coffee offers many benefits—it may help prevent cardiovascular disease, Type 2 diabetes, and Alzheimer’s disease, to name a few. But we’ve also heard that coffee can cause tummy troubles, increased risk of heart disease, and even miscarriages in pregnant women. So which is it? Is coffee good or bad for your health? It turns out the answer depends on how much and how often you consume it, as well as your personal health history.
For the first time this year, the Dietary Guidelines Advisory Committee gave healthy individuals the go ahead to drink a moderate amount of coffee. “Caffeine has long been considered a vice, a nutritional no-no, but newer research has shed a new light on its potential benefits,” says Cynthia Sass, M.P.H., R.D., a dietitian in New York City and Los Angeles and author of Slim Down Now: Shed Pounds and Inches with Real Food, Real Fast.
Moderate coffee intake means three to five cups of coffee a day or up to 400 milligrams (mg) caffeine. (This does not mean sugar- and calorie-laden beverages like a Starbucks Caramel Ribbon Crunch Frappuccino or a Dunkin Donuts Cookie Dough Swirl Latte.) Note that five cups of coffee can contain as little as 375 mg or as much as 1,300 mg—so knowing the caffeine content of what you’re drinking is important. An eight-ounce brewed K-cup, for instance, contains between 75 and 150 mg caffeine, while a tall (12-ounce) Starbucks coffee tops out at 260 mg. Even an 8-ounce decaf cup contains a small amount, between two and 12 mg caffeine per cup.
If you’re looking for more than an energy boost from caffeine, aim to drink the same amount daily at around the same time. “For healthy adults, consistency is the key to reaping potential rewards such as energy boost and disease protection,” says Sass.
The present body of research shows there are many more pros than cons to coffee drinking, but it’s important to have all your information before you sip.
Pro: Coffee May Help You Live Longer
Caffeine isn’t the only ingredient in coffee that offers health benefits. The brew also contains phenolic compounds, antioxidants that may help fight certain types of cancer (such as liver, endometrial, and colorectal), cardiovascular disease, and Type 2 diabetes. Studies have even linked coffee drinking with decreased risk of Parkinson’s disease, which is why drugs containing a caffeine derivative are currently being developed to treat the condition. Because many of coffee’s benefits live in its non-caffeine ingredients, drinking decaffeinated java is also helpful for health, although less so compared to consuming the caffeinated version.
And here’s even better news: Drinking one to four cups of coffee daily may help you live longer, per several studies. In particular, having one to two cups daily is linked with an eight percent decreased risk of death, found a review study published in the British Journal of Nutrition. Even drinking decaf coffee was found to increase lifespan to a lesser degree.
Pro: Coffee Can Improve Memory
While many coffee drinkers are looking for an energy buzz, new research shows coffee’s cognitive benefits may be bigger than ever imagined: Caffeine may enhance memory for up to 24 hours after it’s consumed, per recent research from Johns Hopkins University. Scientists gave people who weren’t regular caffeine consumers either 200 mg caffeine (about the amount in one to two cups of coffee) or a placebo after showing them a series of images. The next day, caffeine consumers were much more likely to remember the images. This is big news because theoretically, this benefit can be ongoing if coffee is consumed daily.
And caffeine offers more memory benefits: It may slightly lower risk of both cognitive decline and Alzheimer’s disease, per preliminary research.
Con: Coffee May Heighten Heart Disease Risk
Just as coffee may decrease risk of heart disease, it may also increase risk for certain individuals. “There is a fairly common genetic mutation that slows the breakdown of caffeine in the body,” explains Sass. “For someone with this gene, caffeine may increase heart disease risk.” The mutation, a variant of the gene CY1A2, causes caffeine to remain in the bloodstream much longer than in the typical person—and the longer it’s in the body, the more potential harm it can create. Speak with your doctor if you’re interested in getting tested for this mutation.
Defect or not, drinking too much coffee may cause increased heartbeat, sleeplessness, and other symptoms. If you have high blood pressure, decaf coffee may be your drink of choice as some studies have linked caffeine intake with heightened blood pressure.
No matter what you decide, remember that caffeine tolerance varies widely. “It’s important to know your body,” says Sass. “Some people can drink a strong cup of coffee and go to sleep 30 minutes later. For others, even a moderate amount can cause stomach upset, anxiety, irritability, sleeplessness, and headaches.”
Con: Coffee May Increase Miscarriage Risk
The general advice for a pregnant woman is to limit caffeine intake to 200 mg per day. Drinking more than this may slightly increase risk of miscarriage—in addition to stillbirth, low birth weight, and small for gestational age births. Of course, if you’re pregnant, it’s best to speak with your doctor to determine if your specific health concerns mean that you should consume even less.
So while coffee offers many health benefits, it can also cause harm if you have certain health conditions or if it’s overconsumed. And it’s important to think about why you’re drinking coffee. “If you’re using caffeine as a Band-Aid for not getting enough sleep, it can be a bad thing—as too much can mask fatigue and cause digestive upset,” says Sass. “As with most things in life, it’s all about balance.