Tea or coffee: Which drink is better for you?

Countless arguments have been waged over the superiority of one beverage over the other. But what does the scientific evidence say?

George Orwell may have written that “tea is one of the mainstays of civilization in this country” – but even we British have to acknowledge that our national drink is facing stiff competition from the espressos, cappuccinos, and lattes invading our shores.
Despite the dangers of wading into such a charged argument, BBC Future decided to weigh up the relative merits of each drink. There’s no accounting for taste, of course, but we have combed the scientific literature for their real, measurable effects on our body and mind.
The wake-up call
For many, the caffeine kick is the primary reason we choose either beverage; it’s the oil to our engines when we’re still feeling a bit creaky in the morning. Based purely on its composition, coffee should win hands down: a cup of tea has about half the dose (40 milligrams) of the stimulant caffeine that you would find in a standard cup of brewed filter coffee (80 to 115 milligrams). Yet this doesn’t necessarily reflect the jolt of the wake-up call.

Caffeine dose is not the whole story: perhaps our expectations also determine how alert we feel

Dosing subjects with either tea or coffee, one (admittedly small) study found that both beverages left subjects feeling similarly alert later in the morning. Although that study was based on self-reported feelings of alertness, clear differences have failed to emerge in more objective measures of concentration, either – such as reaction times. Indeed, when you dose up on tea made to the equivalent strength as coffee, it actually proves to be more effective at sharpening the mind.
The scientists conclude that the caffeine dose is not the whole story: perhaps our expectations also determine how alert we feel, or it could be that it’s the overall experience of the tastes, and smells, of our favourite drink that awakens our senses.
Verdict: Against logic, tea seems to provide just as powerful a wake-up call as coffee. It’s a draw.
Sleep quality
The biggest differences between coffee and tea may emerge once your head hits the pillow.

University of Surrey researchers found that coffee drinkers tend to find it harder to drop off to sleep at night (Credit: iStock)

Comparing people drinking the same volume of tea or coffee over a single day, researchers at the University of Surrey in the UK confirmed that although both drinks lend similar benefits to your attention during the day, coffee drinkers tend to find it harder to drop off at night – perhaps because the higher caffeine content finally catches up with you.
Tea drinkers, in contrast, had longer and more restful slumbers.
Verdict: Tea offers many of the benefits of coffee, without the sleepless nights – a clear win.
Tooth staining
Along with red wine, coffee and tea are both known to turn our pearly whites a murky yellow and brown. But which is worse?

Tea’s natural pigments are more likely to adhere to dental enamel than coffee’s, dentists say (Credit: Getty Images)

Most dentists seem to agree that tea’s natural pigments are more likely to adhere to dental enamel than coffee’s – particularly if you use a mouthwash containing the common antiseptic chlorhexidine, which seems to attract and bind to the microscopic particles.

Verdict: If you want a perfect smile, coffee may be the lesser of two evils.
A balm for troubled souls…
In England, it’s common to give “tea and sympathy” to a distressed friend – the idea being that a cup of Earl Grey is medicine for troubled minds. In fact, there is some evidence that tea can soothe your nerves: regular tea drinkers do tend to show a calmer physiological response to unsettling situations (such as public speaking), compared to people drinking herbal infusions. Overall, people who drink three cups a day appear to have a 37% lower risk of depression than those who do not drink tea.

There is some evidence that tea can soothe your nerves

Coffee doesn’t have the same reputation; indeed, some report that it makes them feel like their nerves are jangling. Yet there is some evidence that it too may protect against long-term mental health problems. A recent “meta-analysis” (summarising the results of studies involving more than 300,000 participants) found that each cup of coffee a day seems to reduce your risk of developing depression by around 8%. In contrast, other beverages (such as sweetened soft drinks) only increase your risk of developing mental health problems.

University of Surrey researchers found that coffee drinkers tend to find it harder to drop off to sleep at night (Credit: iStock)

We need to take such results with a pinch of salt: despite the scientists’ best efforts, in this kind of large epidemiological study it’s hard to rule out other factors that may be behind the link – but it could be that both drinks offer a cocktail of nutrients that dampen down stress responses and boost mood in the long-term.
Verdict: Based on this limited evidence, it’s a draw.
…and a balm for bodies
Similarly tantalising, though preliminary, epidemiological studies have suggested that both coffee and tea offer many other health-giving benefits. A few cups of either beverage a day appears to reduce your risk of diabetes, for instance. (The exact size of the benefit is still under discussion – estimates vary from around 5 to 40%.) Since even decaf coffee confers the same benefits, it seems likely that other nutrients may be oiling the metabolism so that it can still efficiently process blood glucose without becoming insensitive to insulin – the cause of diabetes.

A few cups of either beverage a day appears to reduce your risk of diabetes

Both drinks also seem to moderately protect the heart, although the evidence seems to be slightly stronger for coffee, while tea also appears to be slightly protective against developing a range of cancers – perhaps because of its antioxidants.
Verdict: Another draw – both drinks are a surprising, health-giving elixir.
Overall verdict: Much as we Brits would have liked tea to come out the clear victor, we have to admit there is little between the two drinks besides personal taste. Based solely on the fact that it allows you to get a better night’s sleep, we declare tea the winner – but why not share your own thoughts with us through social media?
 A hot cup of coffee can perk you up in the morning. A soothing cup of tea can help you relax after a stressful day. And the latest research about the health benefits of each might help you feel a little better about them, whichever beverage you drink.
After years of studies that seemed to swing between dire warnings and cheery promises about what our favorite caffeinated beverages do and don’t do, much of the recent science regarding coffee and tea is generally positive.
The WHO’s International Agency for Research on Cancer recently took coffee off its list of suspected carcinogens, and some research suggests it could help keep colon cancer from coming back after treatment. Other studies suggest drinking coffee might stave off Alzheimer’s and Parkinson’s diseases.
Various studies have pointed to tea drinkers having lower odds of skin, breast, and prostate cancers. Researchers are still trying to pinpoint the exact ways that happens. But tea, particularly green tea, is rich in compounds like antioxidants, which can limit cell damage and boost the immune system; and polyphenols, which have been shown to lower blood pressure and cholesterol. It also may help stave off Alzheimer's disease through a polyphenol known as EGCG, which prevents the formation of plaques that are linked to that brain-damaging illness.
Is one better for you than the other?
Experts say that’s hard to say. That’s because it’s difficult to separate out their different ingredients, their role in your diet, and their effects on different body systems.
“I think people are looking at both coffee and tea and how they affect everything, including cancer and GI disease and cardiovascular diseases,” says Elliott Miller, MD, a critical care medicine specialist at the National Institutes of Health.
Miller and his colleagues recently looked at signs of heart disease in more than 6,800 people from different backgrounds across the country. About 75% drank coffee, while about 40% reported drinking tea. Drinking more than one cup of tea regularly was linked to less buildup of calcium in arteries that supply blood to the heart, a development that can lead to heart disease.

Coffee didn’t have an effect either way on heart disease, but that was significant in itself, Miller says.
“Very often patients will ask their doctors, ‘Hey, doc, I’ve got coronary artery disease, or I’ve got risk factors like high blood pressure or cholesterol. Is it safe for me to drink coffee?’ Because everyone thinks drinking coffee makes your heart excited and is potentially bad,” Miller says. “So finding that it’s neutral, I think, is pretty important.”
Researchers say it’s hard to pinpoint exactly how both drinks affect health. Both coffee and tea are “complex beverages” that contain a variety of ingredients. They include caffeine, polyphenols, and antioxidants -- compounds researchers are studying for their potential cancer-fighting properties, says Lisa Cimperman, a clinical dietitian at University Hospitals Case Medical Center.
“It’s more of a dynamic interaction than one single compound,” Cimperman says. Some people have tried to isolate one element in tea or coffee that they think is the secret to one effect or another, “and then they realize that it doesn’t have the same effect.”
Cimperman said drinking tea has been linked to lower risks of cancer and heart disease, improved weight loss, and a stronger immune system. Meanwhile, studies point to coffee as a potential way to head off not just Parkinson’s but type 2 diabetes, liver disease, and heart problems, Cimperman says.
Another recent study, led by Charles Fuchs, MD, director of the Gastrointestinal Cancer Center at Boston’s Dana-Farber Cancer Institute, found regular coffee drinking may help prevent colon cancer from coming back after treatment.
In his study of nearly 1,000 patients, Fuchs says, there was a “significant and linear” association between drinking coffee and lower risk of colon cancer returning in those who drank four or more cups a day. “The more coffee they drank, the lower risk of recurrence.” But the researchers aren’t clear on which element of the drink contributed to that result, and there didn’t seem to be any effect from drinking tea, he says.

“I think you can have two or more cups a day without any concern, and certainly that may benefit you,” Fuchs says. But what about for those who don’t drink coffee? “If it was somebody who hates the stuff and asks, ‘Should I drink it?’ I’d say no. I’d counsel them about diet and exercise and avoiding obesity as measures I think would have a similar benefit.”
Other researchers are asking questions about what role genetics and lifestyle play into the effects of drinking coffee or tea. For instance, coffee and cigarettes once went together like ... well, like coffee and cigarettes, which cause cancer and heart disease.
Some people’s bodies process coffee differently than others, says Martha Gulati, MD, head of cardiology at the University of Arizona College of Medicine in Phoenix. Meanwhile, a preference for tea over coffee might reflect other healthier behaviors, she says.
“Does someone who drinks tea do yoga or meditation more?” Gulati says. “I’m not necessarily saying they’re associated, but do they exercise more? Are they drinking things like green tea to maintain their weight better than other types of drinks?”
And Robert Eckel, MD, an endocrinologist at the University of Denver, says an overall heart-healthy diet is “probably the most important aspect” of preventing heart disease.
“We’re talking about fruits and vegetables, whole grains, lean poultry, fish, legumes, nuts, and avoiding saturated fat. That nutritional message is unchanging,” Eckel says.
There are other variables. The WHO’s ruling on coffee nonetheless cautioned that any kind of extremely hot drinks could raise the risk of esophageal cancer, while Cimperman says dumping a lot of cream and sugar into your drink can blunt any benefits.
“No one beverage or food will make or break your diet,” she says. “The quality of your diet is always the sum of all the parts.”