Costa Coffee's medium cappuccino contains 325mg of caffeine, more than any other hot drink sold by Britain's biggest high street chains, according to new research from consumer group Which?.
That is roughly the same amount of caffeine found in four 250ml cans of Red Bull, which each contain 80mg, Which? said. At the opposite end of the scale, Pret a Manger's Matcha Latte contained just 28mg of caffeine in a 355ml drink, the lowest of any beverage tested.
"For many of us, there is nothing quite like a strong cup of coffee to start the day, but Which? found even matcha enthusiasts could be consuming more caffeine than intended," said Jessica Carson, Which? health and wellbeing expert. "Our research shows caffeine content varies wildly from chain to chain. If you drink multiple cups a day or need to cut back for health reasons, pay attention to where you shop and what you order to avoid any unwanted side effects."
Which? analysed espressos, cappuccinos, filter coffees, flat whites, americanos and matcha lattes sold at Caffè Nero, Costa, Greggs, Starbucks and Pret a Manger. The British Heart Foundation advises that up to 400mg of caffeine a day is generally considered safe for most adults.
Cappuccinos and americanos compared
Costa's cappuccino was far ahead of its rivals. Greggs had the second-highest cappuccino caffeine level at 235mg, followed by Caffè Nero at 221mg.
Americanos showed the widest gap of any drink type across the five chains. A medium americano from Starbucks contained 89mg of caffeine, while the same drink from Costa contained 325mg.
Espresso shots and matcha lattes
Among single espresso shots, Pret a Manger's was the strongest at 180mg, four times the amount found in Starbucks' espresso, which had just 45mg.
Costa's matcha latte contained the most caffeine of any matcha drink tested, at 99mg, while Starbucks' matcha green tea latte had 57mg, more caffeine than Starbucks' own espresso shot.
"This could be a shock for non coffee drinkers looking for jitter-free energy, especially if they are consuming more than one on an empty stomach," Which? said.
Full caffeine rankings
Drinks with the most caffeine, according to Which?:
- Costa Coffee Cappuccino: 325mg
- Costa Coffee Americano: 325mg
- Pret Filter Coffee: 271mg
- Greggs Americano: 257mg
- Costa Coffee Flat White: 241mg
- Greggs Cappuccino: 235mg
- Caffè Nero Cappuccino: 221mg
- Starbucks Filter Coffee: 210mg
- Greggs Latte: 208mg
- Costa Coffee Latte: 200mg
- Caffè Nero Americano: 191mg
- Pret Espresso: 180mg
- Pret Cappuccino: 180mg
- Pret Flat White: 180mg
- Pret Latte: 180mg
- Pret Americano: 180mg
Drinks with the least caffeine:
- Pret Matcha Latte: 28mg
- Starbucks Espresso: 45mg
- Starbucks Matcha Green Tea Latte: 57mg
- Caffè Nero Espresso: 67mg
- Starbucks Americano: 89mg
- Starbucks Latte: 89mg
- Starbucks Flat White: 89mg
- Starbucks Cappuccino: 89mg
- Costa Coffee Matcha Latte: 99mg
- Costa Coffee Espresso: 100mg
- Caffè Nero Flat White: 105mg
- Greggs Flat White: 150mg
- Caffè Nero Latte: 175mg
Health guidance on caffeine intake
The British Heart Foundation, a UK charity that funds research into heart and circulatory disease, says on its website that drinking 400mg or less of caffeine a day should not affect heart rhythm or increase the risk of abnormal heart rhythms such as atrial fibrillation.
"You may find your heart rate increases slightly after consuming caffeine, especially if you're sensitive to its effects," the charity explains. "Some people also experience palpitations, when it feels like your heart is pounding or beating more quickly than usual, if they drink too much."
Chains respond
The Daily Mail, which first reported the findings, contacted Caffè Nero, Starbucks, Greggs and Pret a Manger for comment.
A Costa Coffee spokesperson said: "At Costa Coffee, we're committed to helping customers make informed choices. That's why caffeine and nutritional information is available across our menu and online, so customers can choose the drinks that best suit their individual preferences and needs. We also offer decaffeinated coffee and a range of non-caffeinated drinks. Coffee naturally contains caffeine and levels can vary depending on factors such as the blend, recipe and serving size."
Coffee's wider health effects
Caffeine has been deemed safe for consumption in doses of up to 400mg a day for the general population. Studies suggest it can have a range of health benefits, including combating liver disease and type 2 diabetes, and research has even suggested it could help people live longer.
Coffee is the world's most widely consumed stimulant, and reports show it can boost daily energy expenditure by around 5 per cent. Researchers have said combining two to four daily coffees with regular exercise would be even more effective at keeping weight off, and a 2015 study showed just a couple of cups a day could help dieters stay trim once they have reached their target weight.
