What is caffeine?

Caffeine is a naturally occurring stimulant belonging to the alkaloid family. It has been termed the most widely consumed psychoactive substance in the world. The two most popular sources of caffeine are coffee beans and tea leaves. Other sources include cocoa beans, energy drinks and some over-the-counter medications.


The caffeine content of drinks will vary depending on the type, serving size and how it is prepared.

Discover our full range of health benefit guides, including the health benefits of green tea, and be inspired to mix up your morning cuppa with our coffee recipes.

Coffee beans close up

What are the pros and cons of caffeine?

Whether you’re drinking coffee, tea, caffeinated soft drinks or even hot chocolate, low doses of caffeine may make you feel more alert, energetic and mentally sharp. Research has advanced of late and identified further benefits including promoting the diversification of the gut microbiota to lowering the risk of certain health conditions including type 2 diabetes.

On the downside, caffeine has been identified as a potential risk factor for bone fracture, as it causes calcium to be excreted in the urine and faeces. This depletes the amount retained by the bones and possibly contributes to bone weakening and osteoporosis. For those with sensitive constitutions, excess caffeine may cause diarrhoea and increase the likelihood of Irritable Bowel Syndrome (IBS).

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How much caffeine is safe to drink?

We all metabolise coffee differently – this means even low doses may make some people feel anxious, irritable and unable to switch off or sleep. Dosage really matters and understanding the amount you can tolerate is key to optimising the benefits of caffeine for you.

Over time, excess caffeine may tire the adrenal glands, deplete vital nutrients and interfere with hormonal balance. Too much caffeine may also contribute to insomnia, nervousness, anxiety, gastrointestinal issues and cause heart palpitations.

There is specific advice for pregnant women, so check with your doctor if you are unsure. Also, what you add to your cuppa such as syrups and sugar should be kept to a minimum, because these are ‘free’ sugars, the type we are advised to cut back on. These additions can have a significant impact on your waistline and disrupt blood sugar control.

Mug of black coffee on pink background

How much caffeine is too much?

Before you order that extra-large triple-shot latte, keep in mind that most experts agree that if you’re drinking more than four to five cups of tea, coffee or caffeinated drinks a day, it is best to cut down. Because some people are more sensitive than others, you need to understand your own tolerance and limit it or choose decaf. As a general guide you should aim for no more than 400mg of caffeine per day.

What are the daily caffeine guidelines?

The following guidelines suggest the maximum amounts of caffeine that may be safely consumed each day and how much caffeine you might expect to find in different beverages.

  • Moderate daily caffeine intake at a dose level up to 400mg/day (for a 65kg person)
  • Women who are pregnant should consume no more than 200mg/day (for a 65kg person)
  • Children should consume no more than 45mg-100mg/day (depending on their age)

How much caffeine am I consuming*?

  • Brewed coffee 1 mug (200ml) – 100mg caffeine
  • Instant coffee 1 mug (200ml) – 60mg caffeine
  • Tea 1 mug (200ml) – 45mg caffeine
  • Green tea 1 mug (200ml) – 30-40mg caffeine
  • Can of cola (330ml) – 35mg caffeine
  • Can of energy drink (250ml) – 80mg caffeine
  • Small bar of chocolate (50g) – 5-36mg caffeine

*all figures are approximate

Ground coffee

Is caffeine safe for everyone?

For healthy adults, caffeine consumption is relatively safe. However, for vulnerable groups, levels of caffeine consumption may be harmful and lead to impairments in cardiovascular function, sleep and energy levels. This includes people with uncontrolled high blood pressure.

If you have a mental health condition, high levels of caffeine may worsen your condition. Furthermore, caffeine may reduce the efficacy of certain medications, such as those for anti-psychosis.

How to cut down on caffeine

  • Cut back gradually over a two-to-three week period. Rapid withdrawal may result in headaches. Try diluting smaller amounts of regular coffee to lower your intake.
  • If you’re in a cafe, order a small rather than a large drink.
  • Try decaffeinated tea and coffee – look out for products decaffeinated using the chemical-free Swiss Water method.
  • Make one cup at a time instead of a whole pot/cafetière.
  • Buy a smaller mug
  • Consider herbal varieties such as chicory or dandelion root.
  • Choose caffeine-free soft drinks.
  • Drink more water and herbal teas, as well as fruit and vegetable juices. Dilute juices with sparkling water.
  • Experiment with herbal teas such as lemongrass, peppermint, ginger, red clover, rosehip, nettle and chamomile.

Coffee alternatives to try

Citrus iced tea
Smoky ginger & honey tea
Turmeric tea
Fresh mint tea
Elderflower, lemon & vanilla cordial

Enjoyed this? Check out….

Health benefits of green tea
Health benefits of matcha
Health benefits of rooibos tea

Have you ditched caffeine? How did you do it and what benefits have you found? Share your experiences in the comments below….

A registered Nutritional Therapist, Kerry Torrens is a contributing author to a number of nutritional and cookery publications including BBC Good Food magazine. Kerry is a member of the The Royal Society of Medicine, Complementary and Natural Healthcare Council (CNHC), British Association for Applied Nutrition and Nutritional Therapy (BANT).

Jo Lewin is a registered nutritionist (RNutr) with the Association for Nutrition with a specialism in public health. Follow her on Twitter @nutri_jo.


All health content on bbcgoodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.

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