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Partial to a daily cup of tea? How about two or three? If you've ever wondered how much caffeine is in your favourite cuppa, whether black, green, or herbal, read on. We asked nutritionist Nicola Shubrook to explain.
What is caffeine?
Caffeine is a natural stimulant found in certain plant foods, including tea, coffee, cola nuts, cacao and guarana (found in some energy drinks and bars).
It works by speeding up messages through the central nervous system to the brain helping us to feel, temporarily, more alert and awake. Caffeine affects everyone differently, with some being very sensitive and unable to consume caffeine at all and others who can drinks several cups of tea or coffee with no apparent side effects at all.
Caffeine in tea is fine to drink as part of a balanced diet, but it is best avoided in the afternoon to prevent any disruption to sleep.
Caffeine is not recommended for toddlers and young children, and pregnant women should have no more than 200mg a day.
Whilst there is no direct guidance from the NHS on caffeine intake for adults, a general guide would appear to be a maximum of 400mg a day.
What affects the caffeine content in a cup of tea?
The type of tea leaf used
There are a few factors that affect the levels of caffeine in your cup of tea. Generally, broken tea leaves, as found in tea bags, will impart more caffeine when brewed compared to whole leaves.
The amount of tea used
The more tea leaves added to a cup, the more caffeine will be released. Tea bags naturally provide a standard amount of tea leaf, but if using loose leaf tea you could add more to the pot to increase caffeine levels.
The time taken to brew the tea
The longer the tea leaves sit in hot water, the more caffeine is released.
The temperature of the water used to brew tea
Higher temperatures will also increase the caffeine content as the hot water will act faster to release the caffeine from the leaves.
How much caffeine is in an average cup of black tea with milk?
An average cup of black tea with milk contains around 47mg of caffeine.
Does green tea contain caffeine?
Green tea contains less caffeine than black tea, with on average 33mg per cup.
Matcha green tea, which normally comes in a powder, is much stronger with around 35mg per half a teaspoon.
Do herbal teas contain caffeine?
Herbal teas that don’t come from the Camellia Sinensis plant (or tea plant) are caffeine-free. This includes fruit teas, camomile, ginger, peppermint and rooibos. Technically, these are infusions rather than teas.
However, if you buy herbal tea which has green or black tea added, this will contain caffeine. For example, green tea and mint or green tea and ginger.
Does black tea have more or less caffeine than coffee?
Like for like, a cup of coffee has around double the amount of caffeine compared to black tea, with an average of 95mg per cup. Like tea, a lot of factors can influence the caffeine content of coffee including the type of coffee beans, the roasting process and the type of coffee.
For example, a shot of espresso contains about 63mg of caffeine and a cup of instant coffee between 30-90mg.
This article was published on 30 April 2020.
Nicola Shubrook is a nutritional therapist and works with both private clients and the corporate sector. She is an accredited member of the British Association for Nutrition and Lifestyle Medicine (BANT) and the Complementary & Natural Healthcare Council (CNHC). Find out more at urbanwellness.co.uk.
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