Tea or coffee: which is better for you?

Brits love tea and coffee. They are the two beverages we drink most of in the UK. Sometimes we choose one over the other based on the belief it’s healthier, better for keeping us alert or for calming us, or has fewer side effects. But is there any real reason to choose between tea and coffee, other than personal preference?

Wakey wakey!

The low to moderate (40–300mg) amount of caffeine typically contained in a cup of coffee has been found to improve alertness, attention and reaction time, but has less consistent effects on memory, judgement and decision making.

There’s evidence the effects of caffeine in a cup of tea are enhanced by an amino acid it contains, called L-theanine, if it is drunk regularly. The research finds “L-theanine may interact with caffeine to enhance performance in terms of attention switching and the ability to ignore distraction”. So if you find tea has a more positive effect on keeping you alert, you might be right!

What’s the price of all this extra alertness? After [5–6 hours], around half the caffeine you’ve drunk will still be in your system, and after 10–12 hours, a quarter of it could still be there, according to sleep scientist Matt Walker. This means you may have trouble falling or staying asleep. “Some people tell me [they] can have an espresso with dinner and […] fall asleep fine”, says Walker. But caffeine can decrease the amount of restorative deep sleep you have and as a consequence “you can wake up the next morning and not feel refreshed”, he continues.

One study concludes, “day-long tea consumption produces similar alerting effects to coffee, despite lower caffeine levels, but is less likely to disrupt sleep”. Either way, it’s advisable to limit your consumption of caffeinated drinks (especially those higher in the stimulant) to a long time before you go to bed.

A calming cuppa

Rather than aiming to get a buzz, some people reach for a hot drink to relax.

A University College London (UCL) study found drinking black tea “may speed up recovery from the daily stresses in life”, according to Andrew Steptoe, Professor at the university’s Department of Epidemiology and Public Health. But “we do not know what ingredients of tea were responsible for these effects on stress recovery and relaxation”, he added.

Low-caffeine green tea has also beenfound to reduce stress in some people. The researchers put this down to the earlier mentioned amino acid, L-theanine, which has been found to reduce acute stress and anxiety. L-theanine is also present, in lower concentrations, in black tea.

There’s less research on the effects of coffee on stress, but researchers have found moderate to high amounts of caffeine are linked to higher levels of anxiety.

The NHS advises “drinking too much caffeine can make you more anxious than normal”. So reaching for decaf is best when you’re looking to relax.

How much do they stain your teeth?

Evidence suggests tea stains teeth more than coffee does, including whitened teeth. But both drinks have a staining effect. Dental hygienist Anna Middleton recommends steps to reduce this impact:

• Add milk or a non-dairy alternative to tea and coffee.
• Rinse your mouth out with water or a fluoridated mouthwash after drinking tea or coffee.
• When drinking iced tea or coffee, use a straw.
• Use an electric toothbrush: more brush strokes per minute means more effective plaque removal.
• Clean between teeth with interdental brushes or floss to prevent plaque build-up.
• Use sugar-free mints/gum to increase production of saliva, which acts as a natural buffer in the mouth. Opt for products with Xylitol for extra protection against dental decay.
• Visit your hygienist for professional teeth cleaning.

Which is best for health?

It’s fine to drink tea and coffee as part of a balanced diet, according to the NHS. However, some research suggests caffeinated drinks make the body produce urine more quickly, leading to dehydration.

Both tea and coffee both contain polyphenols, which are “plant compounds that are good for our health”, says dietitian Sophie Medlin. While coffee contains more polyphenols than tea, according to one study, they don’t contain exactly the same types. Both drinks have been linked to a variety of health benefits, including reducing your risk of developing Type-2 diabetes. But drinking in excess of four cups of coffee a day may increase your blood pressure, according to the NHS.

Is green tea better for you than black tea?

While black tea is by far the most popular type of tea in the UK, green tea is growing in popularity – especially with younger adults.Green tea has something of a health halo, but is it that much better for us? Professor of Nutritional Physiology, Justin Roberts, Anglia Ruskin University (ARU) has investigated the benefits of green tea.

“Green tea and black tea come from the same plant camellia sinensis. The difference is how the plant is harvested. With green tea the leaves are frequently grown in the shade, so they get a little bit more time to process. Whereas with black tea, you take the leaves off and oxidize them, turning them into a powder.

“So, the health benefits of green tea could come down to its bioactive properties. Green tea contains a category of polyphenols called flavonoids and within those, certain chemicals like catechins – in particular, a type called epigallocatechin-3-gallate (EGCG).

“It has been proposed that these have some health benefits. But black tea has other compounds, like theaflavins, which also have health benefits. So, there are benefits to both green and black tea.”

However, there is one claim that Roberts isn't convinced about, that drinking green tea could help you to lose weight. "You'd need to drink a lot of it to get any kind of impact…” Plus, he points out: "When people try to lose weight by drinking green tea, it's likely they're taking other steps too - including reducing their calories and taking more exercise, so it's difficult to say that the weight loss is purely down to the tea."

Sensitivity

Some people can be sensitive to caffeine, and if you’re impacted by any side-effects such as digestive issues, anxiety or impaired sleep, you may want to choose tea over coffee, or switch to decaf drinks.

If you decide to cut out caffeine, it is best to do so gradually to avoid severe withdrawal symptoms. The severity of symptoms typically increases according to how much caffeine you drink. You could expect coffee drinkers to have worse symptoms than tea drinkers, due to the higher caffeine content, but it depends how much you drink.

Pregnant women should “limit their intake of caffeinated drinks”, according to the NHS, and caffeine is unsuitable for toddlers and young children.

Originally published April 2021, updated November 2024