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Welcome to the Health Defence Blog - a blog about health, wellness and a healthier you. Brought to you by the Health Defence team at Chest Heart & Stroke Scotland, you'll find up-to-date information on a range of topics from what's in your food to the latest advice on e-cigarettes!


Megan - Health Promotion Specialist

June 22, 2018

That ‘buzz’ you get from a cup of coffee or energy drink comes from the caffeine content in these drinks. Caffeine makes us feel more alert and reduces tiredness but you can have too much of a good thing. Read on to find out how much caffeine is safe to consume every day, how to cut back and find out if ‘decaf’ actually means ‘caffeine-free’.

What is caffeine?

Caffeine is a stimulant that can help you to feel more alert and reduce feelings of fatigue. Caffeine works by blocking the receptors in the brain that make you feel sleepy. The effects of caffeine are usually highest 15 – 45 minutes after consuming a caffeine-containing food or drink.

Where caffeine is found and how much is safe?

Caffeine is found in a number of foods and drinks and the amount can vary between products. For example, an instant coffee tends to have less caffeine than an espresso. The type of beans or tea leaves used and the size of cup also affects the caffeine content.

Generally, it is considered safe for most adults to consume up to 400mg of caffeine per day. However, some people should limit their intake further, such as pregnant women who should have no more than 200mg per day.

Common sources of caffeine:

  • Coffee – a major source of caffeine for many people
  • Tea – black tea has more caffeine than green tea
  • Energy drinks such as Red Bull, Monster, V or Relentless
  • Some foods such as chocolate (dark chocolate has more caffeine than milk chocolate. White chocolate has no caffeine)
  • Some medicines such as cold & flu remedies and some pain killers contain caffeine. Caffeine can make these medications more effective.

Caffeine content of foods and drinks 

*Please note: this list is not exhaustive and these are approximations only. For reference, a mug of filter coffee contains 140mg caffeine and a double-shot espresso or latte has 150-200mg caffeine. 

What 400mg per day can look like (remember this is the upper limit):

  • Four mugs of tea and one 250ml can of energy drink
  • Four to five mugs of instant coffee (depending on the strength)
  • Two double-shot lattes
  • Two 500ml cans of energy drink and one can of cola

Caffeine and health

Everyone responds to caffeine differently and some people are more sensitive to caffeine than others. Whilst drinking tea and coffee can be part of a healthy diet, consuming too much caffeine can cause:

  • Changes in your mood – feeling anxious or nervous
  • Insomnia – it’s best to avoid caffeine later in the day to prevent trouble sleeping
  • Headaches
  • May contribute to high blood pressure (for short periods after consuming it)
  • If you suffer from irritable bowel syndrome, caffeine can make this worse
  • More trips to the bathroom – caffeine is a diuretic which increases the loss of water from the body as urine
  • Palpitations in some people (a rapid thumping or fluttering feeling in your chest)

Are there any benefits?

When looking at the benefits of caffeine, it’s the type of beverage that contains the caffeine that is linked to health. For example, drinking coffee may be good for your health, but high-sugar colas are not.

When it comes to drinking coffee, the evidence is mixed but coffee appears to do more good, than harm. Drinking coffee may be beneficial due to high levels of antioxidants (but we also get these in our diet from fruit and vegetables). Both regular and decaffeinated coffee is linked to a lower risk of developing type 2 diabetes and may reduce heart disease and stroke risk.

Reducing your caffeine intake

Reducing your caffeine intake isn’t always as easy as it sounds. Just like having too much caffeine, some people may experience caffeine withdrawal symptoms such as headaches or irritability.

The best way to reduce your caffeine intake is to do so gradually.

  • Try some caffeine-free or decaf beverages – see the list below!
  • To minimise any caffeine withdrawal symptoms, reduce your intake slowly over a week or two. For example, reduce your intake by half a cup a day.
  • Drink plenty of water (this may help to combat headaches caused by cutting back)
  • Make a smaller cup of tea or coffee and only make one cup at a time (rather than a whole pot)
  • If you’re ordering out, buy a smaller beverage or try a decaf version

Caffeine free beverages

  • Water – try sparkling water or adding some flavour with slices of lemon or cucumber
  • Fruit and vegetable juices are naturally caffeine free
  • Herbal teas – for example, peppermint, ginger or rooibos tea (tip: green tea contains some caffeine, but less than regular tea depending on how long you steep it for)
  • Decaffeinated (‘decaf’) coffee or tea isn’t caffeine free but does contain significantly less caffeine. For example, a decaf instant coffee has about 5mg of caffeine (95mg less than a regular instant coffee).

Caffeine increases your energy and alertness and drinking coffee may have additional health benefits. However, listen to your body and limit your intake if you are having trouble sleeping or become anxious.

Want more? For tips on how to enjoy your coffee and keep your waistline happy at the same time, read our blog Is your morning coffee making you fat?’ 

***Disclaimer: always seek medical advice before starting a new diet, exercise regime or medication. The information in these articles is not a substitute for professional advice from a GP, registered dietitian or other health practitioner.

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