Coffee vs Tea: Which is Healthier? (In-depth Comparison)
The question of coffee vs tea is up there with Republican vs Democrat as one that divides families and communities!
You’re probably already firmly on one side of the debate. Perhaps you like the energy boost of coffee in the morning?
Or maybe you prefer the traditional ritual of afternoon tea? But have you ever wondered which of these two beverages is healthier?
Wonder no more! We’re going to take you through the health benefits of coffee vs tea. And who knows? Maybe when we’re finished, you’ll be ready to switch sides!
Everyone knows that it’s the caffeine that gives us the pick-me-up from our cup of tea and coffee. And everyone also knows that coffee has more caffeine than tea. So that must mean that coffee makes us more alert than tea, right?
Well, apparently not. Believe it or not, scientists comparing the two drinks have found that there’s little to choose between them (1).
Let’s start by recapping on the ingredients. Is it really true that coffee has more caffeine than tea?
In reality, there are all sorts of variables that affect just how much caffeine a cup of coffee contains – serving size, bean variety brewing temperature and style, etc. So that doesn’t take us very far.
However, a 2004 British study looked at how people actually prepared their drinks. This found that there was a total of 40mg of caffeine in the average cup of black tea, compared to 105mg in drip coffee (2).
So that’s more than twice as much caffeine in an average cup of coffee than in tea. Surely that must make a difference?
A 1998 study suggests that’s not the case. This looked at 19 people who regularly consumed caffeine. Each person was given a 100mg sample of tea, coffee or caffeinated water.
All the subjects reported that they felt more alert following the drinks. But despite the different levels of caffeine consumed, tea and coffee had similar effects on cognition (3).
That’s a pretty surprising result. The measurements, though, were based on the feelings of alertness reported by the test subjects. Perhaps there’s a difference when we look at more objective measures?
Well, no. Other studies have looked at factors like reaction times. In fact, when people consumed the same amount of caffeine through tea as coffee, they were actually more alert than the coffee drinkers (4).
So why is this? The theory goes that it’s not just the caffeine content of tea and coffee that affects our mental alertness. Tea also contains flavonoids, theophylline and theobromine. It may be that those ingredients are also improving our mental sharpness (5).
It’s also possible that people’s expectations play a big part in how they feel after their drink. In other words, if you expect to feel more awake after a cup of tea or coffee, you will.
And perhaps the whole experience of drinking your favorite beverage – its aroma, temperature and taste – itself gives you a boost.
Whatever the reason, when comparing the effects of tea and coffee on mental alertness it’s a dead heat.
Time for bed
But what about what happens at the other end of the day?
If tea and coffee have similar effects on mental alertness, surely they’d have about the same impact on sleeping patterns? Well, here’s another surprise: they don’t.
A study of thirty volunteers in 2000 showed that drinking coffee disrupted sleeping patterns more than tea (6).
It may be that the reason for the difference again lies in the other ingredients present alongside caffeine in tea. Tea also contains antioxidants and an amino acid called L-theanine that isn’t found in coffee.
The antioxidants slow the release of caffeine into the bloodstream, whilst the L-theanine has calming properties. The combination means you don’t have to pay for your increased alertness with a sleepless night.
Does tea or coffee give you a brighter smile?
So far it’s looking pretty positive for tea. But there’s one area where coffee has a distinct advantage: your teeth.
Both tea and coffee are known to stain the enamel on your teeth. Strong black tea and coffee are the biggest culprit – but tea is worse than coffee. So why is that?
To find out, we’ll start by looking at what happens to cause the staining.
Our teeth are covered with fine ridges. When we consume dark colored liquids like tea, coffee and red wine, substances called tannins get stuck in those ridges. Hey presto, a less than dazzling smile.
Black teas typically contain more tannins than coffee, making them more prone to staining your teeth. The tannic acid they contain can also create pores in the enamel. These pores trap pigments from the drink and leave your teeth with yellow or brown stains.
Whether you’re drinking tea or coffee, there are a few things you can do to reduce the chances of staining. One option is to drink through a straw to keep the beverage away from your teeth. If you’re like us, though, you’ll feel pretty silly drinking your tea or coffee through a straw (7)!
So what else can you do?
An easy way to reduce potential damage to your enamel is having a few sips of water after your beverage. Rinsing it around your teeth will prevent the pigments from accumulating. Another option is to chew gum.
If the damage is already done, there are lots of whitening toothpastes on the market to help with stain removal. And having your teeth cleaned at the dentist will remove more stubborn stains.
There are also plenty of homemade remedies, like baking soda, or a paste of lime juice and salt. Some people swear by rubbing the inside of a banana skin or cut strawberry over their teeth.
So coffee, it seems, is better than tea if you want to avoid stains on your teeth. But that’s not the whole story as far as dental health is concerned.
Tea contains fluoride, known for strengthening teeth. What’s more, black tea contains enzymes that attack bacteria in dental plaque that causes cavities.
In 2001, scientists from the College of Dentistry at the University of Illinois found that when volunteers rinsed their mouths with black tea, plaque bacteria stopped growing. It also stopped producing the acid that breaks down tooth enamel and causes cavities (8).
So that sounds like good news for tea. But it’s important to remember that the volunteers in the experiment were rinsing their teeth with tea. Specifically, they were rinsing five times at three-minute intervals. And each time, they rinsed their teeth for 30 seconds.
That’s quite different from what we do when we drink tea. So we need to be cautious before making too many claims about the dental benefits of normal tea drinking.
Calming the nerves?
Many of us reach for a cup of coffee or tea when our stress levels are rising. But do either of them actually have any impact?
The good news is that there is some scientific evidence that both tea and coffee can help calm us down.
In 2006, researchers at University College London undertook a study to explore whether tea helped with stress. They withdrew normal tea, coffee and caffeinated drinks from 75 regular tea drinkers for a six-week period (9).
They divided the group into two and gave one group a tea-colored drink containing all the ingredients of black tea. The second group was given a drink with the same flavor, but none of the tea ingredients.
At the end of the six weeks, the volunteers were put in stressful role-playing scenarios. All of them reported feeling stressed, and their bodies showed signs of stress too. Everyone had higher levels of the stress hormone cortisol, and higher heart rates and blood pressure.
But while both groups showed stress, the group that had been drinking the real tea recovered more quickly. Fifty minutes later, their cortisol levels had dropped by almost half. The people who had been drinking “fake” tea had experienced a much lower drop of only 27 percent.
There was more. The tea drinkers showed fewer symptoms linked to blood clotting and heart attacks, and reported greater relaxation after the task (10).
This is good news for tea drinkers’ heart health. Other research has shown slow recovery from stress is associated with a greater risk of illnesses like coronary heart disease.
The scientists noted that tea contained a complex mix of different compounds. For that reason, they said, they couldn’t be sure what was responsible for the positive results.
Fast forward to 2015, however, and Portuguese scientists found that caffeine might be responsible. They found that mice regularly exposed to stressful situations quickly lost their appetite and became anxious.
Fortunately for the poor mice, this wasn’t the end of the story. When they were given water with caffeine to drink before being exposed to stress, most of their symptoms disappeared (11).
So if caffeine is the remedy for stress, both tea and coffee will help soothe frazzled nerves.
In fact, research has found that people who drink three cups of tea a day have a 37% lower risk of depression than those who don’t drink tea.
As for coffee, a 2016 analysis of a series of studies covering over 300,000 people also had good news. Each cup of coffee drunk per day seemed to decrease people’s risk of developing depression by 8 percent (12).
It’s important to recognize that there may be a whole range of other factors having an effect alongside the tea and coffee drinking. But it does seem that both drinks have positive effects on stress.
A host of studies have looked at whether tea or coffee has benefits in terms of the prevention of disease. The results are fascinating.
A 2015 Harvard study found that coffee reduced the risk of premature death from a range of diseases. Drinking three to five cups a day appeared to reduce the risk of cardiovascular and neurological diseases, type 2 diabetes, and even suicide. The reduction in risk also applied to decaf.
The researchers noted that coffee had anti-inflammatory properties and reduced insulin resistance. But as with other studies, they weren’t able to make a direct link between any ingredient and health benefits (13).
Other research indicates that both tea and coffee protect the heart, though the evidence for coffee is stronger.
Tea, on the other hand, seems to offer protection against a range of cancers, which isn’t the case for coffee (14).
Scientists found a significant inverse association between the amounts of black tea drunk and the rate of cancer deaths. In other words, drinking more black tea was associated with a lower risk of dying of cancer (15).
On the negative side, unfiltered coffee contains substances that can increase cholesterol levels. It’s also more acidic than tea, so if you have a sensitive digestive system, tea may be a better option (16).
There are some negatives for tea too. A 1982 study found that it could reduce the amount of iron you absorb from vegetables. Volunteers who drank a cup of tea with their meal absorbed 62 percent less iron than those who didn’t.
People who drank coffee with their meal also absorbed less iron. In their case, however, the reduction was far lower – 35 percent (17).
So is tea or coffee healthier?
We’ve seen that both tea and coffee have a range of benefits – and a few drawbacks too. It’s clear there’s no overall winner in terms of the health impacts. So the good news is there’s no reason not to choose your favorite hot drink based on taste!
It’s still worth thinking about the different advantages and disadvantages though. If you have trouble getting to sleep at night, tea probably has the edge over coffee. Then again, if you drink a lot and want to avoid staining your teeth, coffee is the better option.
We’d love to hear what you think about coffee vs tea. Please comment and let us know!