Green Tea vs. Coffee: Which Is Better for You? We Asked a Nutritionist

You’ve started your day with a cup of coffee for as long as you can remember. But maybe the caffeine doesn’t work its magic like it once did—or maybe it’s actually too powerful these days. It’s no surprise your coworker’s green tea is looking more appetizing every week. But is there that big a difference health-wise between the two drinks? We called on Dr. Felicia Stoler, DCN, a registered dietitian, nutritionist and exercise physiologist, to settle the green tea vs. coffee debate once and for all.  

“They’re both very different in terms of structure, flavonoids and antioxidants,” says Stoler. The main caveat for both drinks is really their caffeine content—and how your body personally reacts to it. For instance, if you have no side effects from consuming caffeine but have acid reflux, green tea might be the better choice for you. If you literally hate the taste of green tea but coffee makes you jittery, it’s safe to stick to the java and cut back or use a mix of decaf and regular grounds. The TLDR: They’re both fine to drink on the regular—it’s just a matter of choosing what’s best for your body and needs. “Both [drinks] naturally contain caffeine, but there are decaffeinated versions available. I actually think if people consumed both, that would be great," says Stoler. "[It will] add some variety to the types of antioxidants and phytonutrients that you receive."

Let’s face it: Most of us don’t drink coffee every day for our health. It’s typically for the caffeine boost, which we count on to drag us out of dream mode (and um, bed) and into real life every morning. We’d guess most green tea drinkers are in it for the energy boost too, though it has less caffeine. And the fact is, it’s tough for scientists to conclusively narrow down the perks or pitfalls of either drink. “The challenge with the research in humans is that it’s impossible to do longitudinal studies on [coffee or green tea] to isolate the benefits or harm without other confounding factors,” says Stoler. So, what do we know for sure?

Coffee, once colloquially thought to wreak havoc on the heart, is actually healthier than you may realize (before you add your caramel syrup and creamer, that is). Coffee is rich in antioxidants, which can help protect against type 2 diabetes, Parkinson’s and certain types of cancer. Some people also swear that coffee helps keep their bowel movements regular. Coffee’s caffeine content is great for times when you need a short burst of energy and focus, say before you hit the gym or give a big presentation at work.

Green tea is better for mellow relaxation and a subtler energy boost (it kills the 3-o’clock slump like a charm). Packed with cancer-fighting polyphenols, it can help burn fat, lower cholesterol and boost your metabolism. It can help fight against potential diseases like dementia, Alzheimer’s and Parkinson’s, as well as reduce your risk for heart attack or stroke. Green tea is loaded with antioxidants that help your body detox, slow aging and combat inflammation. Most notably, green tea has a ton of L-theanine, an amino acid that boosts dopamine and reduces anxiety. It may help you relax so well during the day that your quality of sleep might actually improve.

Stoler also notes that both beverages are solid ways to stay hydrated. “For people who don't like plain water, drinking coffee or green tea are a great way to increase fluid consumption. However, if you’re drinking either with lots of added ingredients (milk, cream, sweeteners, syrups, etc.), then it’s an easy way to add unnecessary calories.”

Both the main pro and con to each of these beverages is caffeine—the side you’re on just depends on your body’s reactions to it. “Nobody wants a rapid heart rate or to be kept up all night,” says Stoler. Caffeine’s consequent effects are actually why some experts don’t recommend having a cup of joe first thing in the morning—especially women. Coffee increases cortisol, aka the stress hormone that helps regulate your energy and alertness throughout the day. Cortisol is naturally high in the morning, so giving yourself an extra dose when you wake up can blunt its production and get your natural cycle out of whack. In fact, some studies show that it can cause you to naturally produce more cortisol than you need. That can negatively impact your ovulation, weight and hormones over time.

If you’re drinking coffee first thing in the morning and on an empty stomach, here’s why you shouldn’t: Coffee stimulates acid production in the stomach (if you’re prone to GI issues or have GERD, odds are you already learned that the hard way). Neutralizing your stomach acid (and that of the coffee) with a calcium-rich breakfast, like yogurt and almonds, can save you a lot of discomfort down the line. Other potential downsides to drinking coffee may include reduced bone density, an increase in cholesterol and higher risk for heart disease—but the studies are sparse and the results are all in all pretty inconclusive. 

Green tea, on the other hand, is easier on the gut than coffee and pretty low-risk all around, unless you have a history of kidney stones. Green and black tea have high levels of oxalates, which can lead to the formation of more stones (though it’s pretty rare). Other downsides include stained teeth after long-term consumption, which coffee can also cause, and weakened iron absorption. Tanins, an antioxidant in tea, can interfere with and reduce how much iron your body actually absorbs in a meal.

It all comes down to the caffeine. If you’re switching from green tea to coffee, you might notice you’re a little more jittery than usual. But switching from coffee to tea might give you symptoms of caffeine withdrawal. According to the Cleveland Clinic, cutting yourself off cold turkey can bring on headache, fatigue, concentration issues, muscle pain and even flu-like nausea. Withdrawal can last up to nine days; the more caffeine you’re used to consuming, the more severe the withdrawal can be. Since we’re talking about switching from coffee to green tea, you won’t be totally cut off from caffeine. Just try gradually reducing your intake (or substituting coffee with tea or decaf coffee) for a few days until you feel no symptoms.

If caffeine is still an issue even when you’ve switched to drinking mostly tea, think about switching to decaffeinated tea or coffee. Removing the caffeine and its effects from the equation actually sort of levels the playing field for both beverages. But you should know: Decaffeinated tea and coffee may not be as beneficial, because the decaffeinating process strips the drinks of some of their antioxidants. So, just decide what’s best for you based on the reason why you drink coffee or green tea in the first place: the energy boost, the health benefits or the routine itself.  

If you’re hopping on the green tea train, drink it in the morning to wake up your brain, or during an afternoon slump—the exact time doesn’t matter much, because green tea actually *reduces* stress hormones like cortisol. And just for the record, you shouldn’t drink either beverage right before bed. Green tea has a third of the amount of caffeine that coffee does (about 30 milligrams versus 96), but it’s still to be avoided in the evening, namely in the couple of hours before you hit the hay. It’s still significant enough to trigger your hormones and adrenals, which translates to less sleep and late-night alertness.

Bottom line: Pay attention to how your body feels as you tweak your daily routine. Are you sleeping better? Feeling less anxious? Take note of what makes you feel your best and run with it. “Hot or cold, both drinks are great to consume and have health benefits,” says Stoler. “So, instead of thinking of it as either/or, consider how to make both work in the day.”